diff --git a/src/Psalm/Codebase.php b/src/Psalm/Codebase.php
index 63ba43330..256f5c5f1 100644
--- a/src/Psalm/Codebase.php
+++ b/src/Psalm/Codebase.php
@@ -95,7 +95,7 @@ class Codebase
     /**
      * @var null|'always'|'auto'
      */
-    public $find_unused_code = null;
+    public $find_unused_code;
 
     /**
      * @var FileProvider
@@ -179,7 +179,7 @@ class Codebase
     /**
      * @var ?Internal\Codebase\TaintFlowGraph
      */
-    public $taint_flow_graph = null;
+    public $taint_flow_graph;
 
     /**
      * @var bool
@@ -614,7 +614,7 @@ class Codebase
 
     public function getStubbedConstantType(string $const_id): ?Type\Union
     {
-        return isset(self::$stubbed_constants[$const_id]) ? self::$stubbed_constants[$const_id] : null;
+        return self::$stubbed_constants[$const_id] ?? null;
     }
 
     /**
@@ -1614,7 +1614,7 @@ class Codebase
             $insertion_text = Type::getStringFromFQCLN(
                 $fq_class_name,
                 $aliases && $aliases->namespace ? $aliases->namespace : null,
-                $aliases ? $aliases->uses_flipped : [],
+                $aliases->uses_flipped ?? [],
                 null
             );
 
diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index bd8ad77d2..7f58038ed 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -55,7 +55,6 @@ use function getcwd;
 use function glob;
 use function implode;
 use function in_array;
-use function intval;
 use function is_a;
 use function is_dir;
 use function is_file;
@@ -80,7 +79,6 @@ use function strlen;
 use function strpos;
 use function strrpos;
 use function strtolower;
-use function strtr;
 use function substr;
 use function substr_count;
 use function sys_get_temp_dir;
@@ -182,7 +180,7 @@ class Config
      *
      * @var bool|null
      */
-    public $load_xdebug_stub = null;
+    public $load_xdebug_stub;
 
     /**
      * The directory to store PHP Parser (and other) caches
@@ -288,7 +286,7 @@ class Config
     /**
      * @var ?bool
      */
-    public $show_mixed_issues = null;
+    public $show_mixed_issues;
 
     /** @var bool */
     public $strict_binary_operands = false;
@@ -501,7 +499,7 @@ class Config
     public $hash = '';
 
     /** @var string|null */
-    public $error_baseline = null;
+    public $error_baseline;
 
     /**
      * @var bool
@@ -978,7 +976,7 @@ class Config
         }
 
         if (isset($config_xml['maxStringLength'])) {
-            $attribute_text = intval($config_xml['maxStringLength']);
+            $attribute_text = (int)$config_xml['maxStringLength'];
             $config->max_string_length = $attribute_text;
         }
 
@@ -2115,7 +2113,7 @@ class Config
         $psr4_prefixes = $this->composer_class_loader->getPrefixesPsr4();
 
         // PSR-4 lookup
-        $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . '.php';
+        $logicalPathPsr4 = str_replace('\\', DIRECTORY_SEPARATOR, $class) . '.php';
 
         $candidate_path = null;
 
@@ -2200,11 +2198,7 @@ class Config
 
     public function getPhpVersion(): ?string
     {
-        if (isset($this->configured_php_version)) {
-            return $this->configured_php_version;
-        }
-
-        return $this->getPHPVersionFromComposerJson();
+        return $this->configured_php_version ?? $this->getPHPVersionFromComposerJson();
     }
 
     private function setBooleanAttribute(string $name, bool $value): void
diff --git a/src/Psalm/Config/Creator.php b/src/Psalm/Config/Creator.php
index 6ddf8a7a2..e54294888 100644
--- a/src/Psalm/Config/Creator.php
+++ b/src/Psalm/Config/Creator.php
@@ -76,13 +76,11 @@ class Creator
             );
         }
 
-        $template = str_replace(
+        return str_replace(
             'errorLevel="1"',
             'errorLevel="' . $level . '"',
             $template
         );
-
-        return $template;
     }
 
     public static function createBareConfig(
diff --git a/src/Psalm/Config/ProjectFileFilter.php b/src/Psalm/Config/ProjectFileFilter.php
index 6899e435d..dc03681f0 100644
--- a/src/Psalm/Config/ProjectFileFilter.php
+++ b/src/Psalm/Config/ProjectFileFilter.php
@@ -11,7 +11,7 @@ class ProjectFileFilter extends FileFilter
     /**
      * @var ProjectFileFilter|null
      */
-    private $file_filter = null;
+    private $file_filter;
 
     /**
      * @return static
diff --git a/src/Psalm/Context.php b/src/Psalm/Context.php
index 97c5564b3..34c74cabc 100644
--- a/src/Psalm/Context.php
+++ b/src/Psalm/Context.php
@@ -103,7 +103,7 @@ class Context
     /**
      * @var null|CodeLocation
      */
-    public $include_location = null;
+    public $include_location;
 
     /**
      * @var string|null
@@ -194,7 +194,7 @@ class Context
      *
      * @var array<string, bool>|null
      */
-    public $initialized_methods = null;
+    public $initialized_methods;
 
     /**
      * @var array<string, Type\Union>
@@ -290,27 +290,27 @@ class Context
     /**
      * @var Internal\Scope\LoopScope|null
      */
-    public $loop_scope = null;
+    public $loop_scope;
 
     /**
      * @var Internal\Scope\CaseScope|null
      */
-    public $case_scope = null;
+    public $case_scope;
 
     /**
      * @var Internal\Scope\FinallyScope|null
      */
-    public $finally_scope = null;
+    public $finally_scope;
 
     /**
      * @var Context|null
      */
-    public $if_context = null;
+    public $if_context;
 
     /**
      * @var \Psalm\Internal\Scope\IfScope|null
      */
-    public $if_scope = null;
+    public $if_scope;
 
     /**
      * @var bool
@@ -418,7 +418,7 @@ class Context
                     ? $end_context->vars_in_scope[$var_id]
                     : null;
 
-                $existing_type = isset($this->vars_in_scope[$var_id]) ? $this->vars_in_scope[$var_id] : null;
+                $existing_type = $this->vars_in_scope[$var_id] ?? null;
 
                 if (!$existing_type) {
                     if ($new_type) {
diff --git a/src/Psalm/DocComment.php b/src/Psalm/DocComment.php
index e4b2f53bc..bb0fb86ea 100644
--- a/src/Psalm/DocComment.php
+++ b/src/Psalm/DocComment.php
@@ -16,6 +16,7 @@ use function rtrim;
 use function str_repeat;
 use function str_replace;
 use function strlen;
+use function strpos;
 use function strspn;
 use function substr;
 use function trim;
@@ -156,7 +157,7 @@ class DocComment
         $docblock = preg_replace('/^\s*\n/', '', $docblock);
 
         foreach ($special as $special_key => $_) {
-            if (substr($special_key, 0, 6) === 'psalm-') {
+            if (strpos($special_key, 'psalm-') === 0) {
                 $special_key = substr($special_key, 6);
 
                 if (!in_array(
@@ -186,7 +187,7 @@ class DocComment
         );
 
         foreach ($parsed_docblock->tags as $special_key => $_) {
-            if (substr($special_key, 0, 6) === 'psalm-') {
+            if (strpos($special_key, 'psalm-') === 0) {
                 $special_key = substr($special_key, 6);
 
                 if (!in_array(
diff --git a/src/Psalm/FileManipulation.php b/src/Psalm/FileManipulation.php
index 891f02dac..e94489fe5 100644
--- a/src/Psalm/FileManipulation.php
+++ b/src/Psalm/FileManipulation.php
@@ -55,7 +55,7 @@ class FileManipulation
             $indentation = substr($existing_contents, $newline_pos, $this->start - $newline_pos);
 
             if (trim($indentation) === '') {
-                $this->insertion_text = $this->insertion_text . $indentation;
+                $this->insertion_text .= $indentation;
             }
         }
 
diff --git a/src/Psalm/Internal/Analyzer/CanAlias.php b/src/Psalm/Internal/Analyzer/CanAlias.php
index eaa47fd21..573125b8c 100644
--- a/src/Psalm/Internal/Analyzer/CanAlias.php
+++ b/src/Psalm/Internal/Analyzer/CanAlias.php
@@ -47,7 +47,7 @@ trait CanAlias
 
         foreach ($stmt->uses as $use) {
             $use_path = implode('\\', $use->name->parts);
-            $use_alias = $use->alias ? $use->alias->name : $use->name->getLast();
+            $use_alias = $use->alias->name ?? $use->name->getLast();
 
             switch ($use->type !== PhpParser\Node\Stmt\Use_::TYPE_UNKNOWN ? $use->type : $stmt->type) {
                 case PhpParser\Node\Stmt\Use_::TYPE_FUNCTION:
@@ -107,7 +107,7 @@ trait CanAlias
 
         foreach ($stmt->uses as $use) {
             $use_path = $use_prefix . '\\' . implode('\\', $use->name->parts);
-            $use_alias = $use->alias ? $use->alias->name : $use->name->getLast();
+            $use_alias = $use->alias->name ?? $use->name->getLast();
 
             switch ($use->type !== PhpParser\Node\Stmt\Use_::TYPE_UNKNOWN ? $use->type : $stmt->type) {
                 case PhpParser\Node\Stmt\Use_::TYPE_FUNCTION:
diff --git a/src/Psalm/Internal/Analyzer/ClassAnalyzer.php b/src/Psalm/Internal/Analyzer/ClassAnalyzer.php
index 5cd72ec1f..0d5116bc8 100644
--- a/src/Psalm/Internal/Analyzer/ClassAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/ClassAnalyzer.php
@@ -368,7 +368,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
                             $this->fq_class_name . ', defined abstract in ' . $declaring_class_name,
                             new CodeLocation(
                                 $this,
-                                $class->name ? $class->name : $class,
+                                $class->name ?? $class,
                                 $class_context->include_location,
                                 true
                             )
@@ -984,7 +984,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
             return;
         }
 
-        $fq_class_name = $class_context->self ? $class_context->self : $this->fq_class_name;
+        $fq_class_name = $class_context->self ?: $this->fq_class_name;
         $fq_class_name_lc = strtolower($fq_class_name);
 
         $included_file_path = $this->getFilePath();
@@ -1913,9 +1913,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
             );
         }
 
-        $overridden_method_ids = isset($class_storage->overridden_method_ids[strtolower($stmt->name->name)])
-            ? $class_storage->overridden_method_ids[strtolower($stmt->name->name)]
-            : [];
+        $overridden_method_ids = $class_storage->overridden_method_ids[strtolower($stmt->name->name)] ?? [];
 
         if (!$return_type
             && !$class_storage->is_interface
@@ -2276,7 +2274,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
 
             $code_location = new CodeLocation(
                 $this,
-                $class->name ? $class->name : $class,
+                $class->name ?? $class,
                 $class_context->include_location,
                 true
             );
@@ -2488,7 +2486,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
             $code_location = new CodeLocation(
                 $this,
                 $extended_class,
-                $class_context ? $class_context->include_location : null,
+                $class_context->include_location ?? null,
                 true
             );
 
@@ -2592,7 +2590,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
                 $code_location = new CodeLocation(
                     $this,
                     $class->name ?: $class,
-                    $class_context ? $class_context->include_location : null,
+                    $class_context->include_location ?? null,
                     true
                 );
 
diff --git a/src/Psalm/Internal/Analyzer/ClassLikeAnalyzer.php b/src/Psalm/Internal/Analyzer/ClassLikeAnalyzer.php
index f1b66b95e..622cf8b15 100644
--- a/src/Psalm/Internal/Analyzer/ClassLikeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/ClassLikeAnalyzer.php
@@ -454,7 +454,7 @@ abstract class ClassLikeAnalyzer extends SourceAnalyzer
 
     public function getClassName(): ?string
     {
-        return $this->class->name ? $this->class->name->name : null;
+        return $this->class->name->name ?? null;
     }
 
     /**
@@ -580,22 +580,17 @@ abstract class ClassLikeAnalyzer extends SourceAnalyzer
                 return $emit_issues ? null : true;
 
             case self::VISIBILITY_PRIVATE:
-                if (!$context->self || $appearing_property_class !== $context->self) {
-                    if ($emit_issues && IssueBuffer::accepts(
-                        new InaccessibleProperty(
-                            'Cannot access private property ' . $property_id . ' from context ' . $context->self,
-                            $code_location
-                        ),
-                        $suppressed_issues
-                    )) {
-                        // fall through
-                    }
-
-                    return null;
+                if ($emit_issues && IssueBuffer::accepts(
+                    new InaccessibleProperty(
+                        'Cannot access private property ' . $property_id . ' from context ' . $context->self,
+                        $code_location
+                    ),
+                    $suppressed_issues
+                )) {
+                    // fall through
                 }
 
-                return $emit_issues ? null : true;
-
+                return null;
             case self::VISIBILITY_PROTECTED:
                 if (!$context->self) {
                     if ($emit_issues && IssueBuffer::accepts(
diff --git a/src/Psalm/Internal/Analyzer/FunctionLike/ReturnTypeAnalyzer.php b/src/Psalm/Internal/Analyzer/FunctionLike/ReturnTypeAnalyzer.php
index c0d39267a..eb0d8e49a 100644
--- a/src/Psalm/Internal/Analyzer/FunctionLike/ReturnTypeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/FunctionLike/ReturnTypeAnalyzer.php
@@ -41,8 +41,8 @@ use Psalm\Type;
 use function array_diff;
 use function count;
 use function in_array;
+use function strpos;
 use function strtolower;
-use function substr;
 
 /**
  * @internal
@@ -109,7 +109,7 @@ class ReturnTypeAnalyzer
         $is_to_string = $function instanceof ClassMethod && strtolower($function->name->name) === '__tostring';
 
         if ($function instanceof ClassMethod
-            && substr($function->name->name, 0, 2) === '__'
+            && strpos($function->name->name, '__') === 0
             && !$is_to_string
             && !$return_type
         ) {
@@ -170,7 +170,7 @@ class ReturnTypeAnalyzer
 
         $function_always_exits = $control_actions === [ScopeAnalyzer::ACTION_END];
 
-        $function_returns_implicitly = !!array_diff(
+        $function_returns_implicitly = (bool)array_diff(
             $control_actions,
             [ScopeAnalyzer::ACTION_END, ScopeAnalyzer::ACTION_RETURN]
         );
@@ -748,8 +748,8 @@ class ReturnTypeAnalyzer
             $fleshed_out_return_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
                 $codebase,
                 $storage->return_type,
-                $classlike_storage ? $classlike_storage->name : null,
-                $classlike_storage ? $classlike_storage->name : null,
+                $classlike_storage->name ?? null,
+                $classlike_storage->name ?? null,
                 $parent_class
             );
 
@@ -770,8 +770,8 @@ class ReturnTypeAnalyzer
         $fleshed_out_signature_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
             $codebase,
             $storage->signature_return_type,
-            $classlike_storage ? $classlike_storage->name : null,
-            $classlike_storage ? $classlike_storage->name : null,
+            $classlike_storage->name ?? null,
+            $classlike_storage->name ?? null,
             $parent_class
         );
 
@@ -792,8 +792,8 @@ class ReturnTypeAnalyzer
         $fleshed_out_return_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
             $codebase,
             $storage->return_type,
-            $classlike_storage ? $classlike_storage->name : null,
-            $classlike_storage ? $classlike_storage->name : null,
+            $classlike_storage->name ?? null,
+            $classlike_storage->name ?? null,
             $parent_class,
             true,
             true
@@ -936,7 +936,7 @@ class ReturnTypeAnalyzer
                 true
             ),
             $inferred_return_type->canBeFullyExpressedInPhp($codebase->php_major_version, $codebase->php_minor_version),
-            $function_like_storage ? $function_like_storage->return_type_description : null
+            $function_like_storage->return_type_description ?? null
         );
     }
 }
diff --git a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
index 524a204ca..0cf5923e0 100644
--- a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
@@ -1624,16 +1624,6 @@ abstract class FunctionLikeAnalyzer extends SourceAnalyzer
         return [];
     }
 
-    public function getFQCLN(): ?string
-    {
-        return $this->source->getFQCLN();
-    }
-
-    public function getClassName(): ?string
-    {
-        return $this->source->getClassName();
-    }
-
     /**
      * @return array<string, array<string, Type\Union>>|null
      */
@@ -1647,16 +1637,6 @@ abstract class FunctionLikeAnalyzer extends SourceAnalyzer
         return $this->storage->template_types;
     }
 
-    public function getParentFQCLN(): ?string
-    {
-        return $this->source->getParentFQCLN();
-    }
-
-    public function getNodeTypeProvider() : \Psalm\NodeTypeProvider
-    {
-        return $this->source->getNodeTypeProvider();
-    }
-
     public function isStatic(): bool
     {
         return $this->is_static;
diff --git a/src/Psalm/Internal/Analyzer/MethodComparator.php b/src/Psalm/Internal/Analyzer/MethodComparator.php
index 977f23448..154cb460f 100644
--- a/src/Psalm/Internal/Analyzer/MethodComparator.php
+++ b/src/Psalm/Internal/Analyzer/MethodComparator.php
@@ -26,8 +26,8 @@ use Psalm\Storage\MethodStorage;
 use Psalm\Type;
 
 use function in_array;
+use function strpos;
 use function strtolower;
-use function substr;
 
 class MethodComparator
 {
@@ -412,7 +412,7 @@ class MethodComparator
                 && $implementer_classlike_storage->user_defined
                 && $implementer_param->location
                 && $guide_method_storage->cased_name
-                && substr($guide_method_storage->cased_name, 0, 2) !== '__'
+                && strpos($guide_method_storage->cased_name, '__') !== 0
                 && $config->isInProjectDirs(
                     $implementer_param->location->file_path
                 )
diff --git a/src/Psalm/Internal/Analyzer/ProjectAnalyzer.php b/src/Psalm/Internal/Analyzer/ProjectAnalyzer.php
index 8dcb978bd..ad7eb1b46 100644
--- a/src/Psalm/Internal/Analyzer/ProjectAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/ProjectAnalyzer.php
@@ -660,7 +660,7 @@ class ProjectAnalyzer
         $this->codebase->classlikes->consolidateAnalyzedData(
             $this->codebase->methods,
             $this->progress,
-            !!$this->codebase->find_unused_code
+            (bool)$this->codebase->find_unused_code
         );
     }
 
@@ -688,7 +688,7 @@ class ProjectAnalyzer
                 && $destination_pos === (strlen($destination) - 1)
             ) {
                 foreach ($this->codebase->classlike_storage_provider->getAll() as $class_storage) {
-                    if (substr($class_storage->name, 0, $source_pos) === substr($source, 0, -1)) {
+                    if (strpos($source, substr($class_storage->name, 0, $source_pos)) === 0) {
                         $this->to_refactor[$class_storage->name]
                             = substr($destination, 0, -1) . substr($class_storage->name, $source_pos);
                     }
@@ -1334,13 +1334,11 @@ class ProjectAnalyzer
 
         $file_path = $this->codebase->scanner->getClassLikeFilePath($fq_class_name_lc);
 
-        $file_analyzer = new FileAnalyzer(
+        return new FileAnalyzer(
             $this,
             $file_path,
             $this->config->shortenFileName($file_path)
         );
-
-        return $file_analyzer;
     }
 
     public function getMethodMutations(
diff --git a/src/Psalm/Internal/Analyzer/Statements/Block/ForeachAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Block/ForeachAnalyzer.php
index 124381ebd..713de3d8d 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Block/ForeachAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Block/ForeachAnalyzer.php
@@ -250,7 +250,7 @@ class ForeachAnalyzer
                 $foreach_context->branch_point ?: (int) $stmt->getAttribute('startFilePos');
         }
 
-        if ($stmt->keyVar && $stmt->keyVar instanceof PhpParser\Node\Expr\Variable && is_string($stmt->keyVar->name)) {
+        if ($stmt->keyVar instanceof PhpParser\Node\Expr\Variable && is_string($stmt->keyVar->name)) {
             $key_type = $key_type ?: Type::getMixed();
 
             AssignmentAnalyzer::analyze(
diff --git a/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/ElseIfAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/ElseIfAnalyzer.php
index de9a01690..9ff0bda05 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/ElseIfAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/ElseIfAnalyzer.php
@@ -159,7 +159,7 @@ class ElseIfAnalyzer
             if (array_filter(
                 $entry_clauses,
                 function ($clause): bool {
-                    return !!$clause->possibilities;
+                    return (bool)$clause->possibilities;
                 }
             )) {
                 $omit_keys = array_reduce(
diff --git a/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/IfAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/IfAnalyzer.php
index 24cf46aac..ac8e7e55d 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/IfAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Block/IfElse/IfAnalyzer.php
@@ -139,7 +139,7 @@ class IfAnalyzer
                     $if_scope->reasonable_clauses = Context::filterClauses(
                         $var_id,
                         $if_scope->reasonable_clauses,
-                        isset($if_context->vars_in_scope[$var_id]) ? $if_context->vars_in_scope[$var_id] : null,
+                        $if_context->vars_in_scope[$var_id] ?? null,
                         $statements_analyzer
                     );
                 }
diff --git a/src/Psalm/Internal/Analyzer/Statements/Block/IfElseAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Block/IfElseAnalyzer.php
index 93241c267..26de808b9 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Block/IfElseAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Block/IfElseAnalyzer.php
@@ -234,7 +234,7 @@ class IfElseAnalyzer
         if (array_filter(
             $context->clauses,
             function ($clause): bool {
-                return !!$clause->possibilities;
+                return (bool)$clause->possibilities;
             }
         )) {
             $omit_keys = array_reduce(
@@ -449,9 +449,7 @@ class IfElseAnalyzer
                     $if_scope->reasonable_clauses = Context::filterClauses(
                         $var_id,
                         $if_scope->reasonable_clauses,
-                        isset($context->vars_in_scope[$var_id])
-                            ? $context->vars_in_scope[$var_id]
-                            : null,
+                        $context->vars_in_scope[$var_id] ?? null,
                         $statements_analyzer
                     );
                 }
diff --git a/src/Psalm/Internal/Analyzer/Statements/Block/SwitchCaseAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Block/SwitchCaseAnalyzer.php
index bbedadc6c..1a7afc01e 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Block/SwitchCaseAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Block/SwitchCaseAnalyzer.php
@@ -39,6 +39,7 @@ use function array_merge;
 use function count;
 use function in_array;
 use function is_string;
+use function strpos;
 use function substr;
 
 /**
@@ -82,7 +83,7 @@ class SwitchCaseAnalyzer
 
         $fake_switch_condition = false;
 
-        if ($switch_var_id && substr($switch_var_id, 0, 15) === '$__tmp_switch__') {
+        if ($switch_var_id && strpos($switch_var_id, '$__tmp_switch__') === 0) {
             $switch_condition = new VirtualVariable(
                 substr($switch_var_id, 1),
                 $stmt->cond->getAttributes()
@@ -402,7 +403,7 @@ class SwitchCaseAnalyzer
                     $case_context->inside_loop,
                     new CodeLocation(
                         $statements_analyzer->getSource(),
-                        $case->cond ? $case->cond : $case,
+                        $case->cond ?? $case,
                         $context->include_location
                     )
                 );
diff --git a/src/Psalm/Internal/Analyzer/Statements/BreakAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/BreakAnalyzer.php
index 97c2246fb..2295dff5c 100644
--- a/src/Psalm/Internal/Analyzer/Statements/BreakAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/BreakAnalyzer.php
@@ -21,10 +21,7 @@ class BreakAnalyzer
         if ($loop_scope) {
             if ($context->break_types
                 && \end($context->break_types) === 'switch'
-                && (!$stmt->num
-                    || !$stmt->num instanceof PhpParser\Node\Scalar\LNumber
-                    || $stmt->num->value < 2
-                )
+                && (!$stmt->num instanceof PhpParser\Node\Scalar\LNumber || $stmt->num->value < 2)
             ) {
                 $loop_scope->final_actions[] = ScopeAnalyzer::ACTION_LEAVE_SWITCH;
             } else {
diff --git a/src/Psalm/Internal/Analyzer/Statements/ContinueAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/ContinueAnalyzer.php
index 49759c6a4..f13daeec0 100644
--- a/src/Psalm/Internal/Analyzer/Statements/ContinueAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/ContinueAnalyzer.php
@@ -17,10 +17,7 @@ class ContinueAnalyzer
         PhpParser\Node\Stmt\Continue_ $stmt,
         Context $context
     ): void {
-        $count = $stmt->num
-            && $stmt->num instanceof PhpParser\Node\Scalar\LNumber
-            ? $stmt->num->value
-            : 1;
+        $count = $stmt->num instanceof PhpParser\Node\Scalar\LNumber? $stmt->num->value : 1;
 
         $loop_scope = $context->loop_scope;
 
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
index 2a1b9d4f8..c1ccd6a27 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
@@ -133,7 +133,7 @@ class AssertionFinder
                 $this_class_name,
                 $source,
                 $codebase,
-                false,
+                false, //should this be $inside_negation??
                 $cache,
                 $inside_conditional
             );
@@ -147,7 +147,7 @@ class AssertionFinder
                 $this_class_name,
                 $source,
                 $codebase,
-                false,
+                false, //should this be $inside_negation??
                 $cache,
                 $inside_conditional
             );
@@ -2114,7 +2114,7 @@ class AssertionFinder
         ?Codebase $codebase,
         bool $inside_negation,
         int $false_position
-    ) {
+    ): array {
         $if_types = [];
 
         if ($false_position === self::ASSIGNMENT_TO_RIGHT) {
@@ -2492,7 +2492,7 @@ class AssertionFinder
                     $if_types[$var_name] = [['!=object']];
                 } elseif ($var_type === 'resource (closed)') {
                     $if_types[$var_name] = [['!closed-resource']];
-                } elseif (substr($var_type, 0, 10) === 'resource (') {
+                } elseif (strpos($var_type, 'resource (') === 0) {
                     $if_types[$var_name] = [['!=resource']];
                 } else {
                     $if_types[$var_name] = [['!' . $var_type]];
@@ -2550,7 +2550,7 @@ class AssertionFinder
                 $if_types[$var_name] = [['!=object']];
             } elseif ($var_type === 'resource (closed)') {
                 $if_types[$var_name] = [['!closed-resource']];
-            } elseif (substr($var_type, 0, 10) === 'resource (') {
+            } elseif (strpos($var_type, 'resource (') === 0) {
                 $if_types[$var_name] = [['!=resource']];
             } else {
                 $if_types[$var_name] = [['!' . $var_type]];
@@ -2807,7 +2807,7 @@ class AssertionFinder
         bool $inside_negation,
         bool $cache,
         int $true_position
-    ) {
+    ): array {
         $if_types = [];
 
         if ($true_position === self::ASSIGNMENT_TO_RIGHT) {
@@ -3173,7 +3173,7 @@ class AssertionFinder
                     $if_types[$var_name] = [['=object']];
                 } elseif ($var_type === 'resource (closed)') {
                     $if_types[$var_name] = [['closed-resource']];
-                } elseif (substr($var_type, 0, 10) === 'resource (') {
+                } elseif (strpos($var_type, 'resource (') === 0) {
                     $if_types[$var_name] = [['=resource']];
                 } else {
                     $if_types[$var_name] = [[$var_type]];
@@ -3231,7 +3231,7 @@ class AssertionFinder
                 $if_types[$var_name] = [['=object']];
             } elseif ($var_type === 'resource (closed)') {
                 $if_types[$var_name] = [['closed-resource']];
-            } elseif (substr($var_type, 0, 10) === 'resource (') {
+            } elseif (strpos($var_type, 'resource (') === 0) {
                 $if_types[$var_name] = [['=resource']];
             } else {
                 $if_types[$var_name] = [[$var_type]];
@@ -3418,7 +3418,7 @@ class AssertionFinder
         if ($first_var_name) {
             $first_arg = $expr->args[0]->value;
             $second_arg = $expr->args[1]->value;
-            $third_arg = isset($expr->args[2]->value) ? $expr->args[2]->value : null;
+            $third_arg = $expr->args[2]->value ?? null;
 
             if ($third_arg instanceof PhpParser\Node\Expr\ConstFetch) {
                 if (!in_array(strtolower($third_arg->name->parts[0]), ['true', 'false'])) {
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssignmentAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssignmentAnalyzer.php
index 02a0c287f..07a61a267 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/AssignmentAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/AssignmentAnalyzer.php
@@ -62,7 +62,6 @@ use function is_string;
 use function reset;
 use function strpos;
 use function strtolower;
-use function substr;
 
 /**
  * @internal
@@ -232,8 +231,7 @@ class AssignmentAnalyzer
 
         if ($comment_type && $comment_type_location) {
             $temp_assign_value_type = $assign_value_type
-                ? $assign_value_type
-                : ($assign_value ? $statements_analyzer->node_data->getType($assign_value) : null);
+                ?? ($assign_value ? $statements_analyzer->node_data->getType($assign_value) : null);
 
             if ($codebase->find_unused_variables
                 && $temp_assign_value_type
@@ -361,7 +359,7 @@ class AssignmentAnalyzer
             if (!$assign_var instanceof PhpParser\Node\Expr\PropertyFetch
                 && !strpos($root_var_id ?? '', '->')
                 && !$comment_type
-                && substr($var_id ?? '', 0, 2) !== '$_'
+                && strpos($var_id ?? '', '$_') !== 0
             ) {
                 $origin_locations = [];
 
@@ -1350,9 +1348,8 @@ class AssignmentAnalyzer
 
                         $can_be_empty = !$assign_value_atomic_type instanceof Type\Atomic\TNonEmptyList;
                     } elseif ($assign_value_atomic_type instanceof Type\Atomic\TKeyedArray) {
-                        if ($assign_var_item->key
-                            && ($assign_var_item->key instanceof PhpParser\Node\Scalar\String_
-                                || $assign_var_item->key instanceof PhpParser\Node\Scalar\LNumber)
+                        if (($assign_var_item->key instanceof PhpParser\Node\Scalar\String_
+                            || $assign_var_item->key instanceof PhpParser\Node\Scalar\LNumber)
                             && isset($assign_value_atomic_type->properties[$assign_var_item->key->value])
                         ) {
                             $new_assign_type =
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/BitwiseNotAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/BitwiseNotAnalyzer.php
index 74a2e04d3..25e183d99 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/BitwiseNotAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/BitwiseNotAnalyzer.php
@@ -100,8 +100,7 @@ class BitwiseNotAnalyzer
     private static function addDataFlow(
         StatementsAnalyzer $statements_analyzer,
         PhpParser\Node\Expr $stmt,
-        PhpParser\Node\Expr $value,
-        string $type = 'bitwisenot'
+        PhpParser\Node\Expr $value
     ): void {
         $result_type = $statements_analyzer->node_data->getType($stmt);
         if ($statements_analyzer->data_flow_graph instanceof VariableUseGraph && $result_type) {
@@ -109,7 +108,7 @@ class BitwiseNotAnalyzer
 
             $stmt_value_type = $statements_analyzer->node_data->getType($value);
 
-            $new_parent_node = DataFlowNode::getForAssignment($type, $var_location);
+            $new_parent_node = DataFlowNode::getForAssignment('bitwisenot', $var_location);
             $statements_analyzer->data_flow_graph->addNode($new_parent_node);
             $result_type->parent_nodes = [
                 $new_parent_node->id => $new_parent_node,
@@ -117,7 +116,7 @@ class BitwiseNotAnalyzer
 
             if ($stmt_value_type && $stmt_value_type->parent_nodes) {
                 foreach ($stmt_value_type->parent_nodes as $parent_node) {
-                    $statements_analyzer->data_flow_graph->addPath($parent_node, $new_parent_node, $type);
+                    $statements_analyzer->data_flow_graph->addPath($parent_node, $new_parent_node, 'bitwisenot');
                 }
             }
         }
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php
index e4c51bec0..22b65571a 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php
@@ -253,12 +253,12 @@ class ArgumentAnalyzer
         $param_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
             $codebase,
             $param_type,
-            $classlike_storage ? $classlike_storage->name : null,
-            $static_classlike_storage ? $static_classlike_storage->name : null,
+            $classlike_storage->name ?? null,
+            $static_classlike_storage->name ?? null,
             $parent_class,
             true,
             false,
-            $static_classlike_storage ? $static_classlike_storage->final : false,
+            $static_classlike_storage->final ?? false,
             true
         );
 
@@ -384,12 +384,12 @@ class ArgumentAnalyzer
             $param_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
                 $codebase,
                 $param_type,
-                $classlike_storage ? $classlike_storage->name : null,
-                $static_classlike_storage ? $static_classlike_storage->name : null,
+                $classlike_storage->name ?? null,
+                $static_classlike_storage->name ?? null,
                 $parent_class,
                 true,
                 false,
-                $static_classlike_storage ? $static_classlike_storage->final : false,
+                $static_classlike_storage->final ?? false,
                 true
             );
         }
@@ -398,8 +398,8 @@ class ArgumentAnalyzer
             ? \Psalm\Internal\Type\TypeExpander::expandUnion(
                 $codebase,
                 $function_param->signature_type,
-                $classlike_storage ? $classlike_storage->name : null,
-                $static_classlike_storage ? $static_classlike_storage->name : null,
+                $classlike_storage->name ?? null,
+                $static_classlike_storage->name ?? null,
                 $parent_class
             )
             : null;
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentsAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentsAnalyzer.php
index 5cfba7e5e..454bdb0c3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentsAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentsAnalyzer.php
@@ -70,8 +70,7 @@ class ArgumentsAnalyzer
             : null;
 
         // if this modifies the array type based on further args
-        if ($method_id
-            && in_array($method_id, ['array_push', 'array_unshift'], true)
+        if (in_array($method_id, ['array_push', 'array_unshift'], true)
             && $function_params
             && isset($args[0])
             && isset($args[1])
@@ -89,7 +88,7 @@ class ArgumentsAnalyzer
             return null;
         }
 
-        if ($method_id && $method_id === 'array_splice' && $function_params && count($args) > 1) {
+        if ($method_id === 'array_splice' && $function_params && count($args) > 1) {
             if (ArrayFunctionArgumentsAnalyzer::handleSplice($statements_analyzer, $args, $context) === false) {
                 return false;
             }
@@ -620,7 +619,7 @@ class ArgumentsAnalyzer
                             $function_params[$i],
                             $i,
                             $i,
-                            $function_storage ? $function_storage->allow_named_arg_calls : true,
+                            $function_storage->allow_named_arg_calls ?? true,
                             new VirtualArg(
                                 StubsGenerator::getExpressionFromType($default_type)
                             ),
@@ -628,7 +627,7 @@ class ArgumentsAnalyzer
                             $context,
                             $class_generic_params,
                             $template_result,
-                            $function_storage ? $function_storage->specialize_call : true,
+                            $function_storage->specialize_call ?? true,
                             $in_call_map
                         );
                     }
@@ -796,13 +795,13 @@ class ArgumentsAnalyzer
                     $function_param,
                     $argument_offset + $i,
                     $i,
-                    $function_storage ? $function_storage->allow_named_arg_calls : true,
+                    $function_storage->allow_named_arg_calls ?? true,
                     $arg,
                     $arg_value_type,
                     $context,
                     $class_generic_params,
                     $template_result,
-                    $function_storage ? $function_storage->specialize_call : true,
+                    $function_storage->specialize_call ?? true,
                     $in_call_map
                 ) === false) {
                     return false;
@@ -1364,12 +1363,12 @@ class ArgumentsAnalyzer
             $fleshed_out_param_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
                 $codebase,
                 $function_param->type,
-                $class_storage ? $class_storage->name : null,
-                $calling_class_storage ? $calling_class_storage->name : null,
+                $class_storage->name ?? null,
+                $calling_class_storage->name ?? null,
                 null,
                 true,
                 false,
-                $calling_class_storage ? $calling_class_storage->final : false
+                $calling_class_storage->final ?? false
             );
 
             TemplateStandinTypeReplacer::replace(
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArrayFunctionArgumentsAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArrayFunctionArgumentsAnalyzer.php
index 70aa20b5f..0239bc9b2 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArrayFunctionArgumentsAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArrayFunctionArgumentsAnalyzer.php
@@ -88,7 +88,7 @@ class ArrayFunctionArgumentsAnalyzer
             $array_arg_types[] = $array_arg_type;
         }
 
-        $closure_arg = isset($args[$closure_index]) ? $args[$closure_index] : null;
+        $closure_arg = $args[$closure_index] ?? null;
 
         $closure_arg_type = null;
 
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallAnalyzer.php
index 4c43208d3..9beaff738 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallAnalyzer.php
@@ -352,7 +352,7 @@ class FunctionCallAnalyzer extends CallAnalyzer
         PhpParser\Node\Name $function_name,
         Context $context,
         CodeLocation $code_location
-    ) {
+    ): FunctionCallInfo {
         $function_call_info = new FunctionCallInfo();
 
         $codebase = $statements_analyzer->getCodebase();
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallInfo.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallInfo.php
index c27baff25..70a193e8c 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallInfo.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallInfo.php
@@ -12,12 +12,12 @@ class FunctionCallInfo
     /**
      * @var ?string
      */
-    public $function_id = null;
+    public $function_id;
 
     /**
      * @var ?bool
      */
-    public $function_exists = null;
+    public $function_exists;
 
     /**
      * @var bool
@@ -42,17 +42,17 @@ class FunctionCallInfo
     /**
      * @var ?array<int, \Psalm\Storage\FunctionLikeParameter>
      */
-    public $function_params = null;
+    public $function_params;
 
     /**
      * @var ?\Psalm\Storage\FunctionLikeStorage
      */
-    public $function_storage = null;
+    public $function_storage;
 
     /**
      * @var ?PhpParser\Node\Name
      */
-    public $new_function_name = null;
+    public $new_function_name;
 
     /**
      * @var bool
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallReturnTypeFetcher.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallReturnTypeFetcher.php
index 1829db052..1da0a3893 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallReturnTypeFetcher.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/FunctionCallReturnTypeFetcher.php
@@ -222,7 +222,7 @@ class FunctionCallReturnTypeFetcher
                 $fake_call_factory = new BuilderFactory();
 
                 if (strpos($proxy_call['fqn'], '::') !== false) {
-                    list($fqcn, $method) = explode('::', $proxy_call['fqn']);
+                    [$fqcn, $method] = explode('::', $proxy_call['fqn']);
                     $fake_call = $fake_call_factory->staticCall($fqcn, $method, $fake_call_arguments);
                 } else {
                     $fake_call = $fake_call_factory->funcCall($proxy_call['fqn'], $fake_call_arguments);
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php
index ab58381d3..eb187adf3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php
@@ -660,7 +660,7 @@ class AtomicMethodCallAnalyzer extends CallAnalyzer
         PhpParser\Node\Expr\MethodCall $stmt,
         StatementsAnalyzer $statements_analyzer,
         string $fq_class_name
-    ) {
+    ): array {
         $naive_method_exists = false;
 
         if ($class_storage->templatedMixins
@@ -749,7 +749,7 @@ class AtomicMethodCallAnalyzer extends CallAnalyzer
         StatementsAnalyzer $statements_analyzer,
         string $fq_class_name,
         ?string $lhs_var_id
-    ) {
+    ): array {
         $naive_method_exists = false;
 
         foreach ($class_storage->namedMixins as $mixin) {
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php
index e92174acb..e1d790932 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php
@@ -103,9 +103,7 @@ class ExistingAtomicMethodCallAnalyzer extends CallAnalyzer
                 $context
             );
 
-            $function_return = $statements_analyzer->node_data->getType($fake_function_call) ?: Type::getMixed();
-
-            return $function_return;
+            return $statements_analyzer->node_data->getType($fake_function_call) ?: Type::getMixed();
         }
 
         $source = $statements_analyzer->getSource();
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodVisibilityAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodVisibilityAnalyzer.php
index 803e902b5..51a99a1fc 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodVisibilityAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodVisibilityAnalyzer.php
@@ -127,10 +127,7 @@ class MethodVisibilityAnalyzer
             // Oldest ancestor is at end of array
             $oldest_ancestor_declaring_method_id = array_pop($overridden_method_ids);
         }
-        $oldest_ancestor_declaring_method_class = null;
-        if ($oldest_ancestor_declaring_method_id) {
-            $oldest_ancestor_declaring_method_class = $oldest_ancestor_declaring_method_id->fq_class_name;
-        }
+        $oldest_ancestor_declaring_method_class = $oldest_ancestor_declaring_method_id->fq_class_name ?? null;
 
         switch ($visibility) {
             case ClassLikeAnalyzer::VISIBILITY_PUBLIC:
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NamedFunctionCallHandler.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NamedFunctionCallHandler.php
index af3fd3be9..73c271193 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NamedFunctionCallHandler.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NamedFunctionCallHandler.php
@@ -60,10 +60,10 @@ class NamedFunctionCallHandler
             return;
         }
 
-        $first_arg = isset($stmt->args[0]) ? $stmt->args[0] : null;
+        $first_arg = $stmt->args[0] ?? null;
 
         if ($function_id === 'method_exists') {
-            $second_arg = isset($stmt->args[1]) ? $stmt->args[1] : null;
+            $second_arg = $stmt->args[1] ?? null;
 
             if ($first_arg
                 && $first_arg->value instanceof PhpParser\Node\Expr\Variable
@@ -223,9 +223,7 @@ class NamedFunctionCallHandler
         if ($function_id === 'func_get_args') {
             $source = $statements_analyzer->getSource();
 
-            if ($statements_analyzer->data_flow_graph
-                && $source instanceof \Psalm\Internal\Analyzer\FunctionLikeAnalyzer
-            ) {
+            if ($source instanceof \Psalm\Internal\Analyzer\FunctionLikeAnalyzer) {
                 if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph) {
                     foreach ($source->param_nodes as $param_node) {
                         $statements_analyzer->data_flow_graph->addPath(
@@ -332,17 +330,13 @@ class NamedFunctionCallHandler
         ) {
             $stmt_assertions = $statements_analyzer->node_data->getAssertions($stmt);
 
-            if ($stmt_assertions !== null) {
-                $anded_assertions = $stmt_assertions;
-            } else {
-                $anded_assertions = AssertionFinder::processFunctionCall(
-                    $stmt,
-                    $context->self,
-                    $statements_analyzer,
-                    $codebase,
-                    $context->inside_negation
-                );
-            }
+            $anded_assertions = $stmt_assertions ?? AssertionFinder::processFunctionCall(
+                $stmt,
+                $context->self,
+                $statements_analyzer,
+                $codebase,
+                $context->inside_negation
+            );
 
             $changed_vars = [];
 
@@ -442,7 +436,7 @@ class NamedFunctionCallHandler
         string $function_id,
         Context $context
     ) : void {
-        $first_arg = isset($stmt->args[0]) ? $stmt->args[0] : null;
+        $first_arg = $stmt->args[0] ?? null;
 
         if ($first_arg) {
             $var = $first_arg->value;
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/CallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/CallAnalyzer.php
index 1b94c2abf..28d16d3f1 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/CallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/CallAnalyzer.php
@@ -191,17 +191,12 @@ class CallAnalyzer
                     || $is_final)
             ) {
                 $local_vars_in_scope = [];
-                $local_vars_possibly_in_scope = [];
 
                 foreach ($context->vars_in_scope as $var_id => $type) {
                     if (strpos($var_id, '$this->') === 0) {
                         if ($type->initialized) {
                             $local_vars_in_scope[$var_id] = $context->vars_in_scope[$var_id];
 
-                            if (isset($context->vars_possibly_in_scope[$var_id])) {
-                                $local_vars_possibly_in_scope[$var_id] = $context->vars_possibly_in_scope[$var_id];
-                            }
-
                             unset($context->vars_in_scope[$var_id]);
                             unset($context->vars_possibly_in_scope[$var_id]);
                         }
@@ -320,7 +315,7 @@ class CallAnalyzer
             $args,
             $method_params,
             (string) $method_id,
-            $method_storage ? $method_storage->allow_named_arg_calls : true,
+            $method_storage->allow_named_arg_calls ?? true,
             $context,
             $class_template_result
         ) === false) {
@@ -419,11 +414,11 @@ class CallAnalyzer
                     $codebase,
                     $type,
                     $appearing_class_name,
-                    $calling_class_storage ? $calling_class_storage->name : null,
+                    $calling_class_storage->name ?? null,
                     null,
                     true,
                     false,
-                    $calling_class_storage ? $calling_class_storage->final : false
+                    $calling_class_storage->final ?? false
                 );
             }
         }
@@ -1032,7 +1027,7 @@ class CallAnalyzer
                     $bounds_with_equality = array_filter(
                         $lower_bounds,
                         function ($lower_bound) {
-                            return !!$lower_bound->equality_bound_classlike;
+                            return (bool)$lower_bound->equality_bound_classlike;
                         }
                     );
 
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
index 81c2f902c..a2cc39f97 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
@@ -66,8 +66,7 @@ class CastAnalyzer
                         new Type\Atomic\TLiteralInt(1),
                     ]);
 
-                    if ($statements_analyzer->data_flow_graph
-                        && $statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
+                    if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
                     ) {
                         $type->parent_nodes = $maybe_type->parent_nodes;
                     }
@@ -79,10 +78,9 @@ class CastAnalyzer
             if ($as_int) {
                 $type = $valid_int_type ?? Type::getInt();
 
-                if ($statements_analyzer->data_flow_graph
-                    && $statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
+                if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
                 ) {
-                    $type->parent_nodes = $maybe_type ? $maybe_type->parent_nodes : [];
+                    $type->parent_nodes = $maybe_type->parent_nodes ?? [];
                 }
 
                 $statements_analyzer->node_data->setType($stmt, $type);
@@ -106,10 +104,9 @@ class CastAnalyzer
 
             $type = Type::getFloat();
 
-            if ($statements_analyzer->data_flow_graph
-                && $statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
+            if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
             ) {
-                $type->parent_nodes = $maybe_type ? $maybe_type->parent_nodes : [];
+                $type->parent_nodes = $maybe_type->parent_nodes ?? [];
             }
 
             $statements_analyzer->node_data->setType($stmt, $type);
@@ -132,10 +129,9 @@ class CastAnalyzer
 
             $type = Type::getBool();
 
-            if ($statements_analyzer->data_flow_graph
-                && $statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
+            if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
             ) {
-                $type->parent_nodes = $maybe_type ? $maybe_type->parent_nodes : [];
+                $type->parent_nodes = $maybe_type->parent_nodes ?? [];
             }
 
             $statements_analyzer->node_data->setType($stmt, $type);
@@ -183,10 +179,9 @@ class CastAnalyzer
 
             $maybe_type = $statements_analyzer->node_data->getType($stmt->expr);
 
-            if ($statements_analyzer->data_flow_graph
-                && $statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
+            if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
             ) {
-                $type->parent_nodes = $maybe_type ? $maybe_type->parent_nodes : [];
+                $type->parent_nodes = $maybe_type->parent_nodes ?? [];
             }
 
             $statements_analyzer->node_data->setType($stmt, $type);
@@ -237,10 +232,9 @@ class CastAnalyzer
                 $type = Type::getArray();
             }
 
-            if ($statements_analyzer->data_flow_graph
-                && $statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
+            if ($statements_analyzer->data_flow_graph instanceof \Psalm\Internal\Codebase\VariableUseGraph
             ) {
-                $type->parent_nodes = $stmt_expr_type ? $stmt_expr_type->parent_nodes : [];
+                $type->parent_nodes = $stmt_expr_type->parent_nodes ?? [];
             }
 
             $statements_analyzer->node_data->setType($stmt, $type);
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
index 75b07f429..d85dc8c71 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
@@ -1833,8 +1833,7 @@ class ArrayFetchAnalyzer
                     [
                         new VirtualArg(
                             $stmt->dim
-                                ? $stmt->dim
-                                : new VirtualConstFetch(
+                                ?? new VirtualConstFetch(
                                     new VirtualName('null'),
                                     $stmt->var->getAttributes()
                                 )
@@ -1957,7 +1956,7 @@ class ArrayFetchAnalyzer
         if ($type instanceof TSingleLetter) {
             $valid_offset_type = Type::getInt(false, 0);
         } elseif ($type instanceof TLiteralString) {
-            if (!strlen($type->value)) {
+            if ($type->value === '') {
                 $valid_offset_type = Type::getEmpty();
             } elseif (strlen($type->value) < 10) {
                 $valid_offsets = [];
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php
index de730ff64..7d6cf6db4 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php
@@ -1112,8 +1112,6 @@ class AtomicPropertyFetchAnalyzer
             $has_magic_getter,
             $var_id
         );
-
-        return;
     }
 
     private static function getClassPropertyType(
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/IncludeAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/IncludeAnalyzer.php
index 36a4fbb6e..a608ab4c7 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/IncludeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/IncludeAnalyzer.php
@@ -84,7 +84,7 @@ class IncludeAnalyzer
 
             // attempts to resolve using get_include_path dirs
             $include_path = self::resolveIncludePath($path_to_file, dirname($statements_analyzer->getFilePath()));
-            $path_to_file = $include_path ? $include_path : $path_to_file;
+            $path_to_file = $include_path ?: $path_to_file;
 
             if (DIRECTORY_SEPARATOR === '/') {
                 $is_path_relative = $path_to_file[0] !== DIRECTORY_SEPARATOR;
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php
index 32398a8e7..ceb43a8a5 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/SimpleTypeInferer.php
@@ -282,9 +282,7 @@ class SimpleTypeInferer
                         }
 
                         return null;
-                    } catch (\InvalidArgumentException $e) {
-                        return null;
-                    } catch (\Psalm\Exception\CircularReferenceException $e) {
+                    } catch (\InvalidArgumentException | \Psalm\Exception\CircularReferenceException $e) {
                         return null;
                     }
                 }
diff --git a/src/Psalm/Internal/Analyzer/Statements/ReturnAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/ReturnAnalyzer.php
index 65791d9d7..31c39ba5d 100644
--- a/src/Psalm/Internal/Analyzer/Statements/ReturnAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/ReturnAnalyzer.php
@@ -633,7 +633,7 @@ class ReturnAnalyzer
             $param->type = self::inferInnerClosureTypeFromParent(
                 $statements_analyzer->getCodebase(),
                 $param->type,
-                $parent_param ? $parent_param->type : null
+                $parent_param->type ?? null
             );
         }
 
diff --git a/src/Psalm/Internal/Analyzer/Statements/UnusedAssignmentRemover.php b/src/Psalm/Internal/Analyzer/Statements/UnusedAssignmentRemover.php
index 0fa0ca3bb..5d25d735f 100644
--- a/src/Psalm/Internal/Analyzer/Statements/UnusedAssignmentRemover.php
+++ b/src/Psalm/Internal/Analyzer/Statements/UnusedAssignmentRemover.php
@@ -132,7 +132,7 @@ class UnusedAssignmentRemover
         $iter = 1;
 
         // Check if second token is just whitespace
-        if (is_array($token_list[$iter]) && strlen(trim($token_list[$iter][1])) === 0) {
+        if (is_array($token_list[$iter]) && trim($token_list[$iter][1]) === '') {
             $offset_count += strlen($token_list[1][1]);
             $iter++;
         }
@@ -146,7 +146,7 @@ class UnusedAssignmentRemover
         $iter++;
 
         // Remove any whitespace following assignment operator token (e.g "=", "+=")
-        if (is_array($token_list[$iter]) && strlen(trim($token_list[$iter][1])) === 0) {
+        if (is_array($token_list[$iter]) && trim($token_list[$iter][1]) === '') {
             $offset_count += strlen($token_list[$iter][1]);
             $iter++;
         }
@@ -156,7 +156,7 @@ class UnusedAssignmentRemover
             $offset_count += 1;
             $iter++;
             // Handle any whitespace after "&"
-            if (is_array($token_list[$iter]) && strlen(trim($token_list[$iter][1])) === 0) {
+            if (is_array($token_list[$iter]) && trim($token_list[$iter][1]) === '') {
                 $offset_count += strlen($token_list[$iter][1]);
             }
         }
diff --git a/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php b/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
index 82e0e91f0..553e57498 100644
--- a/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
@@ -55,6 +55,7 @@ use function get_class;
 use function preg_split;
 use function round;
 use function strlen;
+use function strpos;
 use function strrpos;
 use function strtolower;
 use function substr;
@@ -117,12 +118,12 @@ class StatementsAnalyzer extends SourceAnalyzer
     /**
      * @var ParsedDocblock|null
      */
-    private $parsed_docblock = null;
+    private $parsed_docblock;
 
     /**
      * @var ?string
      */
-    private $fake_this_class = null;
+    private $fake_this_class;
 
     /** @var \Psalm\Internal\Provider\NodeDataProvider */
     public $node_data;
@@ -557,7 +558,7 @@ class StatementsAnalyzer extends SourceAnalyzer
                 $class_analyzer = new ClassAnalyzer(
                     $stmt,
                     $statements_analyzer->source,
-                    $stmt->name ? $stmt->name->name : null
+                    $stmt->name->name ?? null
                 );
 
                 $class_analyzer->analyze(null, $global_context);
@@ -755,7 +756,7 @@ class StatementsAnalyzer extends SourceAnalyzer
         }
 
         foreach ($this->unused_var_locations as [$var_id, $original_location]) {
-            if (substr($var_id, 0, 2) === '$_') {
+            if (strpos($var_id, '$_') === 0) {
                 continue;
             }
 
@@ -911,12 +912,12 @@ class StatementsAnalyzer extends SourceAnalyzer
      */
     public function getFirstAppearance(string $var_id): ?CodeLocation
     {
-        return isset($this->all_vars[$var_id]) ? $this->all_vars[$var_id] : null;
+        return $this->all_vars[$var_id] ?? null;
     }
 
     public function getBranchPoint(string $var_id): ?int
     {
-        return isset($this->var_branch_points[$var_id]) ? $this->var_branch_points[$var_id] : null;
+        return $this->var_branch_points[$var_id] ?? null;
     }
 
     public function addVariableInitialization(string $var_id, int $branch_point): void
diff --git a/src/Psalm/Internal/Cli/LanguageServer.php b/src/Psalm/Internal/Cli/LanguageServer.php
index d6afd30fc..b7d2d58d1 100644
--- a/src/Psalm/Internal/Cli/LanguageServer.php
+++ b/src/Psalm/Internal/Cli/LanguageServer.php
@@ -27,6 +27,7 @@ use function is_string;
 use function preg_replace;
 use function realpath;
 use function setlocale;
+use function strpos;
 use function strtolower;
 use function substr;
 
@@ -85,7 +86,7 @@ final class LanguageServer
              * @param string $arg
              */
             function ($arg) use ($valid_long_options): void {
-                if (substr($arg, 0, 2) === '--' && $arg !== '--') {
+                if (strpos($arg, '--') === 0 && $arg !== '--') {
                     $arg_name = preg_replace('/=.*$/', '', substr($arg, 2));
 
                     if (!in_array($arg_name, $valid_long_options, true)
@@ -309,6 +310,6 @@ HELP;
             $project_analyzer->language_server_verbose = true;
         }
 
-        $project_analyzer->server($options['tcp'] ?? null, isset($options['tcp-server']) ? true : false);
+        $project_analyzer->server($options['tcp'] ?? null, isset($options['tcp-server']));
     }
 }
diff --git a/src/Psalm/Internal/Cli/Psalm.php b/src/Psalm/Internal/Cli/Psalm.php
index b60ba4390..7e80ad592 100644
--- a/src/Psalm/Internal/Cli/Psalm.php
+++ b/src/Psalm/Internal/Cli/Psalm.php
@@ -251,7 +251,7 @@ final class Psalm
             }
         }
 
-        $paths_to_check = CliUtils::getPathsToCheck(isset($options['f']) ? $options['f'] : null);
+        $paths_to_check = CliUtils::getPathsToCheck($options['f'] ?? null);
 
         if ($config->resolve_from_config_file) {
             $current_dir = $config->base_dir;
@@ -420,7 +420,7 @@ final class Psalm
              * @param string $arg
              */
             function ($arg): void {
-                if (substr($arg, 0, 2) === '--' && $arg !== '--') {
+                if (strpos($arg, '--') === 0 && $arg !== '--') {
                     $arg_name = preg_replace('/=.*$/', '', substr($arg, 2));
 
                     if (!in_array($arg_name, self::LONG_OPTIONS)
@@ -434,7 +434,7 @@ final class Psalm
                         );
                         exit(1);
                     }
-                } elseif (substr($arg, 0, 1) === '-' && $arg !== '-' && $arg !== '--') {
+                } elseif (strpos($arg, '-') === 0 && $arg !== '-' && $arg !== '--') {
                     $arg_name = preg_replace('/=.*$/', '', substr($arg, 1));
 
                     if (!in_array($arg_name, self::SHORT_OPTIONS)
diff --git a/src/Psalm/Internal/Cli/Psalter.php b/src/Psalm/Internal/Cli/Psalter.php
index c386fd64f..40bd193f3 100644
--- a/src/Psalm/Internal/Cli/Psalter.php
+++ b/src/Psalm/Internal/Cli/Psalter.php
@@ -201,7 +201,7 @@ HELP;
         // If Xdebug is enabled, restart without it
         (new \Composer\XdebugHandler\XdebugHandler('PSALTER'))->check();
 
-        $paths_to_check = CliUtils::getPathsToCheck(isset($options['f']) ? $options['f'] : null);
+        $paths_to_check = CliUtils::getPathsToCheck($options['f'] ?? null);
 
         $path_to_config = CliUtils::getPathToConfig($options);
 
@@ -434,7 +434,7 @@ HELP;
              * @param string $arg
              */
             function ($arg): void {
-                if (substr($arg, 0, 2) === '--' && $arg !== '--') {
+                if (strpos($arg, '--') === 0 && $arg !== '--') {
                     $arg_name = preg_replace('/=.*$/', '', substr($arg, 2));
 
                     if ($arg_name === 'alter') {
diff --git a/src/Psalm/Internal/Cli/Refactor.php b/src/Psalm/Internal/Cli/Refactor.php
index d235c968a..b63ef6d10 100644
--- a/src/Psalm/Internal/Cli/Refactor.php
+++ b/src/Psalm/Internal/Cli/Refactor.php
@@ -75,7 +75,7 @@ final class Refactor
              * @param string $arg
              */
             function ($arg) use ($valid_long_options): void {
-                if (substr($arg, 0, 2) === '--' && $arg !== '--') {
+                if (strpos($arg, '--') === 0 && $arg !== '--') {
                     $arg_name = preg_replace('/=.*$/', '', substr($arg, 2));
 
                     if ($arg_name === 'refactor') {
diff --git a/src/Psalm/Internal/CliUtils.php b/src/Psalm/Internal/CliUtils.php
index 015f6a34a..821c48ffb 100644
--- a/src/Psalm/Internal/CliUtils.php
+++ b/src/Psalm/Internal/CliUtils.php
@@ -231,7 +231,7 @@ final class CliUtils
         if ($f_paths) {
             $input_paths = is_array($f_paths) ? $f_paths : [$f_paths];
         } else {
-            $input_paths = $argv ? $argv : null;
+            $input_paths = $argv ?: null;
         }
 
         if ($input_paths) {
@@ -264,7 +264,7 @@ final class CliUtils
                     continue;
                 }
 
-                if (substr($input_path, 0, 2) === '--' && strlen($input_path) > 2) {
+                if (strpos($input_path, '--') === 0 && strlen($input_path) > 2) {
                     if (substr($input_path, 2) === 'config') {
                         ++$i;
                     }
diff --git a/src/Psalm/Internal/Codebase/Analyzer.php b/src/Psalm/Internal/Codebase/Analyzer.php
index 37d3c2940..5797be13a 100644
--- a/src/Psalm/Internal/Codebase/Analyzer.php
+++ b/src/Psalm/Internal/Codebase/Analyzer.php
@@ -148,7 +148,7 @@ class Analyzer
      *
      * @var array<string>|null
      */
-    private $files_to_update = null;
+    private $files_to_update;
 
     /**
      * @var array<string, array<string, int>>
@@ -316,7 +316,7 @@ class Analyzer
 
             $project_analyzer->prepareMigration();
 
-            $files_to_update = $this->files_to_update !== null ? $this->files_to_update : $this->files_to_analyze;
+            $files_to_update = $this->files_to_update ?? $this->files_to_analyze;
 
             foreach ($files_to_update as $file_path) {
                 $this->updateFile($file_path, $project_analyzer->dry_run);
@@ -345,7 +345,7 @@ class Analyzer
 
                 $this->progress->debug('Analyzing ' . $file_analyzer->getFilePath() . "\n");
 
-                $file_analyzer->analyze(null);
+                $file_analyzer->analyze();
                 $file_analyzer->context = null;
                 $file_analyzer->clearSourceBeforeDestruction();
                 unset($file_analyzer);
diff --git a/src/Psalm/Internal/Codebase/ConstantTypeResolver.php b/src/Psalm/Internal/Codebase/ConstantTypeResolver.php
index 99f4345f7..a32fed6f9 100644
--- a/src/Psalm/Internal/Codebase/ConstantTypeResolver.php
+++ b/src/Psalm/Internal/Codebase/ConstantTypeResolver.php
@@ -134,12 +134,12 @@ class ConstantTypeResolver
                 || $cond instanceof Type\Atomic\TLiteralString
             ) {
                 if ($cond->value) {
-                    return $if ? $if : $cond;
+                    return $if ?? $cond;
                 }
             } elseif ($cond instanceof Type\Atomic\TFalse || $cond instanceof Type\Atomic\TNull) {
                 return $else;
             } elseif ($cond instanceof Type\Atomic\TTrue) {
-                return $if ? $if : $cond;
+                return $if ?? $cond;
             }
         }
 
diff --git a/src/Psalm/Internal/Codebase/DataFlowGraph.php b/src/Psalm/Internal/Codebase/DataFlowGraph.php
index 5d4f9547a..279e4c0e9 100644
--- a/src/Psalm/Internal/Codebase/DataFlowGraph.php
+++ b/src/Psalm/Internal/Codebase/DataFlowGraph.php
@@ -10,6 +10,7 @@ use function array_merge;
 use function array_reverse;
 use function array_sum;
 use function strlen;
+use function strpos;
 use function substr;
 
 abstract class DataFlowGraph
@@ -65,7 +66,7 @@ abstract class DataFlowGraph
 
         // arraykey-fetch requires a matching arraykey-assignment at the same level
         // otherwise the tainting is not valid
-        if (substr($path_type, 0, $el + 7) === $expression_type . '-fetch-' || $path_type === 'arraykey-fetch') {
+        if (strpos($path_type, $expression_type . '-fetch-') === 0 || $path_type === 'arraykey-fetch') {
             $fetch_nesting = 0;
 
             $previous_path_types = array_reverse($previous_path_types);
@@ -79,11 +80,11 @@ abstract class DataFlowGraph
                     $fetch_nesting--;
                 }
 
-                if (substr($previous_path_type, 0, $el + 6) === $expression_type . '-fetch') {
+                if (strpos($previous_path_type, $expression_type . '-fetch') === 0) {
                     $fetch_nesting++;
                 }
 
-                if (substr($previous_path_type, 0, $el + 12) === $expression_type . '-assignment-') {
+                if (strpos($previous_path_type, $expression_type . '-assignment-') === 0) {
                     if ($fetch_nesting > 0) {
                         $fetch_nesting--;
                         continue;
diff --git a/src/Psalm/Internal/Codebase/InternalCallMapHandler.php b/src/Psalm/Internal/Codebase/InternalCallMapHandler.php
index 57c187a60..f79ef431b 100644
--- a/src/Psalm/Internal/Codebase/InternalCallMapHandler.php
+++ b/src/Psalm/Internal/Codebase/InternalCallMapHandler.php
@@ -14,6 +14,7 @@ use function assert;
 use function count;
 use function dirname;
 use function file_exists;
+use function strpos;
 use function strtolower;
 use function substr;
 use function version_compare;
@@ -32,16 +33,16 @@ class InternalCallMapHandler
     /**
      * @var ?int
      */
-    private static $loaded_php_major_version = null;
+    private static $loaded_php_major_version;
     /**
      * @var ?int
      */
-    private static $loaded_php_minor_version = null;
+    private static $loaded_php_minor_version;
 
     /**
      * @var array<lowercase-string, array<int|string,string>>|null
      */
-    private static $call_map = null;
+    private static $call_map;
 
     /**
      * @var array<list<TCallable>>|null
@@ -274,7 +275,7 @@ class InternalCallMapHandler
                     $optional = true;
                 }
 
-                if (substr($arg_name, 0, 3) === '...') {
+                if (strpos($arg_name, '...') === 0) {
                     $arg_name = substr($arg_name, 3);
                     $variadic = true;
                 }
diff --git a/src/Psalm/Internal/Codebase/Methods.php b/src/Psalm/Internal/Codebase/Methods.php
index 1a928fe7e..2550677b4 100644
--- a/src/Psalm/Internal/Codebase/Methods.php
+++ b/src/Psalm/Internal/Codebase/Methods.php
@@ -360,7 +360,7 @@ class Methods
         if (InternalCallMapHandler::inCallMap((string) $callmap_id)) {
             $class_storage = $this->classlike_storage_provider->get($callmap_id->fq_class_name);
 
-            $declaring_method_name = $declaring_method_id ? $declaring_method_id->method_name : $method_name;
+            $declaring_method_name = $declaring_method_id->method_name ?? $method_name;
 
             if (!$class_storage->stubbed || empty($class_storage->methods[$declaring_method_name]->stubbed)) {
                 $function_callables = InternalCallMapHandler::getCallablesFromCallMap((string) $callmap_id);
@@ -1060,11 +1060,7 @@ class Methods
 
         $method_name = $method_id->method_name;
 
-        if (isset($class_storage->appearing_method_ids[$method_name])) {
-            return $class_storage->appearing_method_ids[$method_name];
-        }
-
-        return null;
+        return $class_storage->appearing_method_ids[$method_name] ?? null;
     }
 
     /**
@@ -1075,11 +1071,7 @@ class Methods
         $class_storage = $this->classlike_storage_provider->get($method_id->fq_class_name);
         $method_name = $method_id->method_name;
 
-        if (isset($class_storage->overridden_method_ids[$method_name])) {
-            return $class_storage->overridden_method_ids[$method_name];
-        }
-
-        return [];
+        return $class_storage->overridden_method_ids[$method_name] ?? [];
     }
 
     public function getCasedMethodId(MethodIdentifier $original_method_id): string
diff --git a/src/Psalm/Internal/Composer.php b/src/Psalm/Internal/Composer.php
index 16abe5369..52ac9350a 100644
--- a/src/Psalm/Internal/Composer.php
+++ b/src/Psalm/Internal/Composer.php
@@ -35,7 +35,7 @@ final class Composer
      */
     public static function getLockFilePath(string $root): string
     {
-        $composer_json_path = static::getJsonFilePath($root);
+        $composer_json_path = self::getJsonFilePath($root);
         return "json" === pathinfo($composer_json_path, PATHINFO_EXTENSION)
             ? substr($composer_json_path, 0, -4).'lock'
             : $composer_json_path . '.lock';
diff --git a/src/Psalm/Internal/ExecutionEnvironment/SystemCommandExecutor.php b/src/Psalm/Internal/ExecutionEnvironment/SystemCommandExecutor.php
index a78e3078d..89d0e3e02 100644
--- a/src/Psalm/Internal/ExecutionEnvironment/SystemCommandExecutor.php
+++ b/src/Psalm/Internal/ExecutionEnvironment/SystemCommandExecutor.php
@@ -24,7 +24,7 @@ final class SystemCommandExecutor
     {
         if (!\function_exists('exec')) {
             throw new \RuntimeException(sprintf('exec does not exist, failed to execute command: %s', $command));
-        };
+        }
 
         exec($command, $result, $returnValue);
 
diff --git a/src/Psalm/Internal/FileManipulation/FileManipulationBuffer.php b/src/Psalm/Internal/FileManipulation/FileManipulationBuffer.php
index e86990cd7..f3c6e3783 100644
--- a/src/Psalm/Internal/FileManipulation/FileManipulationBuffer.php
+++ b/src/Psalm/Internal/FileManipulation/FileManipulationBuffer.php
@@ -169,11 +169,7 @@ class FileManipulationBuffer
      */
     public static function getManipulationsForFile(string $file_path): array
     {
-        if (!isset(self::$file_manipulations[$file_path])) {
-            return [];
-        }
-
-        return self::$file_manipulations[$file_path];
+        return self::$file_manipulations[$file_path] ?? [];
     }
 
     /**
diff --git a/src/Psalm/Internal/Fork/Pool.php b/src/Psalm/Internal/Fork/Pool.php
index 21ef1e432..c9409f10f 100644
--- a/src/Psalm/Internal/Fork/Pool.php
+++ b/src/Psalm/Internal/Fork/Pool.php
@@ -21,7 +21,6 @@ use function get_class;
 use function gettype;
 use function in_array;
 use function ini_get;
-use function intval;
 use function pcntl_fork;
 use function pcntl_waitpid;
 use function pcntl_wexitstatus;
@@ -307,7 +306,7 @@ class Pool
         // resource id.
         $streams = [];
         foreach ($this->read_streams as $stream) {
-            $streams[intval($stream)] = $stream;
+            $streams[(int)$stream] = $stream;
         }
 
         // Create an array for the content received on each stream,
@@ -340,12 +339,12 @@ class Pool
             foreach ($needs_read as $file) {
                 $buffer = fread($file, 1024);
                 if ($buffer !== false) {
-                    $content[intval($file)] .= $buffer;
+                    $content[(int)$file] .= $buffer;
                 }
 
                 if (strpos($buffer, "\n") !== false) {
-                    $serialized_messages = explode("\n", $content[intval($file)]);
-                    $content[intval($file)] = array_pop($serialized_messages);
+                    $serialized_messages = explode("\n", $content[(int)$file]);
+                    $content[(int)$file] = array_pop($serialized_messages);
 
                     foreach ($serialized_messages as $serialized_message) {
                         $message = unserialize(base64_decode($serialized_message, true));
@@ -375,13 +374,13 @@ class Pool
 
                 // If the stream has closed, stop trying to select on it.
                 if (feof($file)) {
-                    if ($content[intval($file)] !== '') {
+                    if ($content[(int)$file] !== '') {
                         error_log('Child did not send full message before closing the connection');
                         $this->did_have_error = true;
                     }
 
                     fclose($file);
-                    unset($streams[intval($file)]);
+                    unset($streams[(int)$file]);
                 }
             }
         }
diff --git a/src/Psalm/Internal/LanguageServer/LanguageServer.php b/src/Psalm/Internal/LanguageServer/LanguageServer.php
index 90f6c77bf..24703864a 100644
--- a/src/Psalm/Internal/LanguageServer/LanguageServer.php
+++ b/src/Psalm/Internal/LanguageServer/LanguageServer.php
@@ -220,7 +220,7 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
 
                 $this->verboseLog("Initializing: Registering stub files...");
                 $this->clientStatus('initializing', 'registering stub files');
-                $codebase->config->visitStubFiles($codebase, null);
+                $codebase->config->visitStubFiles($codebase);
 
                 if ($this->textDocument === null) {
                     $this->textDocument = new TextDocument(
diff --git a/src/Psalm/Internal/LanguageServer/ProtocolStreamReader.php b/src/Psalm/Internal/LanguageServer/ProtocolStreamReader.php
index d982d875e..cde108ce5 100644
--- a/src/Psalm/Internal/LanguageServer/ProtocolStreamReader.php
+++ b/src/Psalm/Internal/LanguageServer/ProtocolStreamReader.php
@@ -37,7 +37,7 @@ class ProtocolStreamReader implements ProtocolReader
     /** @var string[] */
     private $headers = [];
     /** @var ?int */
-    private $content_length = null;
+    private $content_length;
     /** @var bool */
     private $did_emit_close = false;
 
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/AttributeResolver.php b/src/Psalm/Internal/PhpVisitor/Reflector/AttributeResolver.php
index e297ef9f0..315105342 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/AttributeResolver.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/AttributeResolver.php
@@ -26,24 +26,17 @@ class AttributeResolver
     ) : AttributeStorage {
         if ($stmt->name instanceof PhpParser\Node\Name\FullyQualified) {
             $fq_type_string = (string)$stmt->name;
-
-            $codebase->scanner->queueClassLikeForScanning($fq_type_string);
-            $file_storage->referenced_classlikes[strtolower($fq_type_string)] = $fq_type_string;
         } else {
             $fq_type_string = ClassLikeAnalyzer::getFQCLNFromNameObject($stmt->name, $aliases);
-
-            $codebase->scanner->queueClassLikeForScanning($fq_type_string);
-            $file_storage->referenced_classlikes[strtolower($fq_type_string)] = $fq_type_string;
         }
 
+        $codebase->scanner->queueClassLikeForScanning($fq_type_string);
+        $file_storage->referenced_classlikes[strtolower($fq_type_string)] = $fq_type_string;
+
         $args = [];
 
         foreach ($stmt->args as $arg_node) {
-            $key = null;
-
-            if ($arg_node->name) {
-                $key = $arg_node->name->name;
-            }
+            $key = $arg_node->name->name ?? null;
 
             $const_type = SimpleTypeInferer::infer(
                 $codebase,
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeDocblockParser.php b/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeDocblockParser.php
index 7702e6039..8c62963a2 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeDocblockParser.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeDocblockParser.php
@@ -489,7 +489,7 @@ class ClassLikeDocblockParser
         array $specials,
         string $property_tag
     ) : void {
-        $magic_property_comments = isset($specials[$property_tag]) ? $specials[$property_tag] : [];
+        $magic_property_comments = $specials[$property_tag] ?? [];
 
         foreach ($magic_property_comments as $offset => $property) {
             $line_parts = CommentAnalyzer::splitDocLine($property);
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeNodeScanner.php b/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeNodeScanner.php
index fc933678c..11a9b167d 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeNodeScanner.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeNodeScanner.php
@@ -366,12 +366,7 @@ class ClassLikeNodeScanner
                 if ($type_aliases) {
                     $this->classlike_type_aliases = $type_aliases;
                 }
-            } catch (DocblockParseException $e) {
-                $storage->docblock_issues[] = new InvalidDocblock(
-                    $e->getMessage(),
-                    new CodeLocation($this->file_scanner, $node, null, true)
-                );
-            } catch (TypeParseTreeException $e) {
+            } catch (DocblockParseException | TypeParseTreeException $e) {
                 $storage->docblock_issues[] = new InvalidDocblock(
                     $e->getMessage(),
                     new CodeLocation($this->file_scanner, $node, null, true)
@@ -1390,7 +1385,7 @@ class ClassLikeNodeScanner
             );
         }
 
-        $doc_var_group_type = $var_comment ? $var_comment->type : null;
+        $doc_var_group_type = $var_comment->type ?? null;
 
         if ($doc_var_group_type) {
             $doc_var_group_type->queueClassLikesForScanning($this->codebase, $this->file_storage);
@@ -1408,7 +1403,7 @@ class ClassLikeNodeScanner
             $property_storage->type_location = $signature_type_location;
             $property_storage->location = new CodeLocation($this->file_scanner, $property->name);
             $property_storage->stmt_location = new CodeLocation($this->file_scanner, $stmt);
-            $property_storage->has_default = $property->default ? true : false;
+            $property_storage->has_default = (bool)$property->default;
             $property_storage->deprecated = $var_comment ? $var_comment->deprecated : false;
             $property_storage->suppressed_issues = $var_comment ? $var_comment->suppressed_issues : [];
             $property_storage->internal = $var_comment ? $var_comment->psalm_internal ?? '' : '';
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/ExpressionScanner.php b/src/Psalm/Internal/PhpVisitor/Reflector/ExpressionScanner.php
index 34b09d905..a02a5cb83 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/ExpressionScanner.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/ExpressionScanner.php
@@ -281,7 +281,7 @@ class ExpressionScanner
 
             // attempts to resolve using get_include_path dirs
             $include_path = IncludeAnalyzer::resolveIncludePath($path_to_file, dirname($file_storage->file_path));
-            $path_to_file = $include_path ? $include_path : $path_to_file;
+            $path_to_file = $include_path ?: $path_to_file;
 
             if (DIRECTORY_SEPARATOR === '/') {
                 $is_path_relative = $path_to_file[0] !== DIRECTORY_SEPARATOR;
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockParser.php b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockParser.php
index 7aac2cc42..57f0b9a3a 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockParser.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockParser.php
@@ -20,6 +20,7 @@ use function preg_replace;
 use function preg_split;
 use function reset;
 use function str_replace;
+use function stripos;
 use function strlen;
 use function strpos;
 use function strtolower;
@@ -199,7 +200,7 @@ class FunctionLikeDocblockParser
                 if (count($param_parts) === 2) {
                     $taint_type = $param_parts[1];
 
-                    if (substr($taint_type, 0, 5) === 'exec_') {
+                    if (strpos($taint_type, 'exec_') === 0) {
                         $taint_type = substr($taint_type, 5);
 
                         if ($taint_type === 'tainted') {
@@ -375,7 +376,7 @@ class FunctionLikeDocblockParser
             }
         }
 
-        if (strpos(strtolower($parsed_docblock->description), '@inheritdoc') !== false
+        if (stripos($parsed_docblock->description, '@inheritdoc') !== false
             || isset($parsed_docblock->tags['inheritdoc'])
             || isset($parsed_docblock->tags['inheritDoc'])
         ) {
@@ -490,7 +491,7 @@ class FunctionLikeDocblockParser
      * @param list<string> $line_parts
      * @return array{string, string} $line_parts
      */
-    private static function sanitizeAssertionLineParts(array $line_parts)
+    private static function sanitizeAssertionLineParts(array $line_parts): array
     {
         if (count($line_parts) < 2 || strpos($line_parts[1], '$') === false) {
             throw new IncorrectDocblockException('Misplaced variable');
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockScanner.php b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockScanner.php
index 8c01914be..d281fa986 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockScanner.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeDocblockScanner.php
@@ -617,7 +617,7 @@ class FunctionLikeDocblockScanner
             $param_name = $docblock_param['name'];
             $docblock_param_variadic = false;
 
-            if (substr($param_name, 0, 3) === '...') {
+            if (strpos($param_name, '...') === 0) {
                 $docblock_param_variadic = true;
                 $param_name = substr($param_name, 3);
             }
@@ -987,7 +987,7 @@ class FunctionLikeDocblockScanner
 
                 if (isset($flow_parts[0]) && \strpos(trim($flow_parts[0]), 'proxy') === 0) {
                     $proxy_call = trim(substr($flow_parts[0], strlen('proxy')));
-                    list($fully_qualified_name, $source_param_string) = explode('(', $proxy_call, 2);
+                    [$fully_qualified_name, $source_param_string] = explode('(', $proxy_call, 2);
 
                     if (!empty($fully_qualified_name) && !empty($source_param_string)) {
                         $source_params = preg_split('/, ?/', substr($source_param_string, 0, -1)) ?: [];
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php
index 83157e1b3..fb518a1a4 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php
@@ -218,7 +218,7 @@ class FunctionLikeNodeScanner
             }
 
             $existing_params['$' . $param_storage->name] = $i;
-            $storage->addParam($param_storage, !!$param->type);
+            $storage->addParam($param_storage, (bool)$param->type);
 
             if (!$param_storage->is_optional && !$param_storage->is_variadic) {
                 $required_param_count = $i + 1;
@@ -292,7 +292,7 @@ class FunctionLikeNodeScanner
                             $cond_id,
                             $cond_id,
                             $function_stmt->cond,
-                            $this->classlike_storage ? $this->classlike_storage->name : null,
+                            $this->classlike_storage->name ?? null,
                             $this->file_scanner,
                             null
                         );
@@ -585,7 +585,7 @@ class FunctionLikeNodeScanner
                 $property_storage->type_location = $param_storage->type_location;
                 $property_storage->location = $param_storage->location;
                 $property_storage->stmt_location = new CodeLocation($this->file_scanner, $param);
-                $property_storage->has_default = $param->default ? true : false;
+                $property_storage->has_default = (bool)$param->default;
                 $param_storage->promoted_property = true;
                 $property_storage->is_promoted = true;
 
diff --git a/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php b/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php
index 8c1a4c320..7d9793583 100644
--- a/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php
+++ b/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php
@@ -92,7 +92,7 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements FileSour
     /**
      * @var ?int
      */
-    private $skip_if_descendants = null;
+    private $skip_if_descendants;
 
     /**
      * @var array<string, TypeAlias>
@@ -126,17 +126,12 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements FileSour
     {
         foreach ($node->getComments() as $comment) {
             if ($comment instanceof PhpParser\Comment\Doc && !$node instanceof PhpParser\Node\Stmt\ClassLike) {
-                $self_fqcln = $node instanceof PhpParser\Node\Stmt\ClassLike
-                    && $node->name !== null
-                    ? ($this->aliases->namespace ? $this->aliases->namespace . '\\' : '') . $node->name->name
-                    : null;
-
                 try {
                     $type_aliases = Reflector\ClassLikeNodeScanner::getTypeAliasesFromComment(
                         $comment,
                         $this->aliases,
                         $this->type_aliases,
-                        $self_fqcln
+                        null
                     );
 
                     foreach ($type_aliases as $type_alias) {
@@ -145,12 +140,7 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements FileSour
                     }
 
                     $this->type_aliases += $type_aliases;
-                } catch (DocblockParseException $e) {
-                    $this->file_storage->docblock_issues[] = new InvalidDocblock(
-                        $e->getMessage(),
-                        new CodeLocation($this->file_scanner, $node, null, true)
-                    );
-                } catch (TypeParseTreeException $e) {
+                } catch (DocblockParseException | TypeParseTreeException $e) {
                     $this->file_storage->docblock_issues[] = new InvalidDocblock(
                         $e->getMessage(),
                         new CodeLocation($this->file_scanner, $node, null, true)
@@ -434,7 +424,7 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements FileSour
         foreach ($node->uses as $use) {
             $use_path = implode('\\', $use->name->parts);
 
-            $use_alias = $use->alias ? $use->alias->name : $use->name->getLast();
+            $use_alias = $use->alias->name ?? $use->name->getLast();
 
             switch ($use->type !== PhpParser\Node\Stmt\Use_::TYPE_UNKNOWN ? $use->type : $node->type) {
                 case PhpParser\Node\Stmt\Use_::TYPE_FUNCTION:
@@ -467,7 +457,7 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements FileSour
 
         foreach ($node->uses as $use) {
             $use_path = $use_prefix . '\\' . implode('\\', $use->name->parts);
-            $use_alias = $use->alias ? $use->alias->name : $use->name->getLast();
+            $use_alias = $use->alias->name ?? $use->name->getLast();
 
             switch ($use->type !== PhpParser\Node\Stmt\Use_::TYPE_UNKNOWN ? $use->type : $node->type) {
                 case PhpParser\Node\Stmt\Use_::TYPE_FUNCTION:
diff --git a/src/Psalm/Internal/PhpVisitor/SimpleNameResolver.php b/src/Psalm/Internal/PhpVisitor/SimpleNameResolver.php
index 04d41daa3..e2cfdc7b9 100644
--- a/src/Psalm/Internal/PhpVisitor/SimpleNameResolver.php
+++ b/src/Psalm/Internal/PhpVisitor/SimpleNameResolver.php
@@ -68,7 +68,7 @@ class SimpleNameResolver extends NodeVisitorAbstract
             $this->nameContext->startNamespace($node->name);
         } elseif ($node instanceof Stmt\Use_) {
             foreach ($node->uses as $use) {
-                $this->addAlias($use, $node->type, null);
+                $this->addAlias($use, $node->type);
             }
         } elseif ($node instanceof Stmt\GroupUse) {
             foreach ($node->uses as $use) {
diff --git a/src/Psalm/Internal/PluginManager/PluginList.php b/src/Psalm/Internal/PluginManager/PluginList.php
index 2769bace7..916ecdc8e 100644
--- a/src/Psalm/Internal/PluginManager/PluginList.php
+++ b/src/Psalm/Internal/PluginManager/PluginList.php
@@ -18,10 +18,10 @@ class PluginList
     private $composer_lock;
 
     /** @var ?array<string,string> [pluginClass => packageName] */
-    private $all_plugins = null;
+    private $all_plugins;
 
     /** @var ?array<string,?string> [pluginClass => ?packageName] */
-    private $enabled_plugins = null;
+    private $enabled_plugins;
 
     public function __construct(?ConfigFile $config_file, ComposerLock $composer_lock)
     {
diff --git a/src/Psalm/Internal/Provider/FakeFileProvider.php b/src/Psalm/Internal/Provider/FakeFileProvider.php
index 596fecd9d..7d693ec47 100644
--- a/src/Psalm/Internal/Provider/FakeFileProvider.php
+++ b/src/Psalm/Internal/Provider/FakeFileProvider.php
@@ -29,11 +29,7 @@ class FakeFileProvider extends FileProvider
             return $this->temp_files[strtolower($file_path)];
         }
 
-        if (isset($this->fake_files[$file_path])) {
-            return $this->fake_files[$file_path];
-        }
-
-        return parent::getContents($file_path);
+        return $this->fake_files[$file_path] ?? parent::getContents($file_path);
     }
 
     public function setContents(string $file_path, string $file_contents): void
@@ -50,11 +46,7 @@ class FakeFileProvider extends FileProvider
 
     public function getModifiedTime(string $file_path): int
     {
-        if (isset($this->fake_file_times[$file_path])) {
-            return $this->fake_file_times[$file_path];
-        }
-
-        return parent::getModifiedTime($file_path);
+        return $this->fake_file_times[$file_path] ?? parent::getModifiedTime($file_path);
     }
 
     /**
diff --git a/src/Psalm/Internal/Provider/FileReferenceCacheProvider.php b/src/Psalm/Internal/Provider/FileReferenceCacheProvider.php
index 34aff48ae..02b7daa9f 100644
--- a/src/Psalm/Internal/Provider/FileReferenceCacheProvider.php
+++ b/src/Psalm/Internal/Provider/FileReferenceCacheProvider.php
@@ -818,10 +818,7 @@ class FileReferenceCacheProvider
         if ($cache_directory
             && file_exists($config_hash_cache_location)
         ) {
-            /** @var string */
-            $file_maps_cache = file_get_contents($config_hash_cache_location);
-
-            return $file_maps_cache;
+            return file_get_contents($config_hash_cache_location);
         }
 
         return false;
diff --git a/src/Psalm/Internal/Provider/FileReferenceProvider.php b/src/Psalm/Internal/Provider/FileReferenceProvider.php
index 887e6ff32..6bd1c35ef 100644
--- a/src/Psalm/Internal/Provider/FileReferenceProvider.php
+++ b/src/Psalm/Internal/Provider/FileReferenceProvider.php
@@ -78,7 +78,7 @@ class FileReferenceProvider
      *
      * @var array<int, string>|null
      */
-    private static $deleted_files = null;
+    private static $deleted_files;
 
     /**
      * A lookup table used for getting all the files referenced by a file
@@ -447,7 +447,7 @@ class FileReferenceProvider
      */
     public function getFilesReferencingFile(string $file): array
     {
-        return isset(self::$file_references[$file]['a']) ? self::$file_references[$file]['a'] : [];
+        return self::$file_references[$file]['a'] ?? [];
     }
 
     /**
@@ -455,7 +455,7 @@ class FileReferenceProvider
      */
     public function getFilesInheritingFromFile(string $file): array
     {
-        return isset(self::$file_references[$file]['i']) ? self::$file_references[$file]['i'] : [];
+        return self::$file_references[$file]['i'] ?? [];
     }
 
     /**
@@ -691,14 +691,14 @@ class FileReferenceProvider
         foreach ($visited_files as $file => $_) {
             $all_file_references = array_unique(
                 array_merge(
-                    isset(self::$file_references[$file]['a']) ? self::$file_references[$file]['a'] : [],
+                    self::$file_references[$file]['a'] ?? [],
                     $this->calculateFilesReferencingFile($codebase, $file)
                 )
             );
 
             $inheritance_references = array_unique(
                 array_merge(
-                    isset(self::$file_references[$file]['i']) ? self::$file_references[$file]['i'] : [],
+                    self::$file_references[$file]['i'] ?? [],
                     $this->calculateFilesInheritingFile($codebase, $file)
                 )
             );
diff --git a/src/Psalm/Internal/Provider/ParserCacheProvider.php b/src/Psalm/Internal/Provider/ParserCacheProvider.php
index bde4314e2..8a8973f71 100644
--- a/src/Psalm/Internal/Provider/ParserCacheProvider.php
+++ b/src/Psalm/Internal/Provider/ParserCacheProvider.php
@@ -45,7 +45,7 @@ class ParserCacheProvider
      *
      * @var array<string, string>|null
      */
-    private $existing_file_content_hashes = null;
+    private $existing_file_content_hashes;
 
     /**
      * A map of recently-added filename hashes to contents hashes
diff --git a/src/Psalm/Internal/Provider/ProjectCacheProvider.php b/src/Psalm/Internal/Provider/ProjectCacheProvider.php
index e0d9d7c14..0aa52bf36 100644
--- a/src/Psalm/Internal/Provider/ProjectCacheProvider.php
+++ b/src/Psalm/Internal/Provider/ProjectCacheProvider.php
@@ -21,12 +21,12 @@ class ProjectCacheProvider
     /**
      * @var int|null
      */
-    private $last_run = null;
+    private $last_run;
 
     /**
      * @var string|null
      */
-    private $composer_lock_hash = null;
+    private $composer_lock_hash;
 
     private $composer_lock_location;
 
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFilterReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFilterReturnTypeProvider.php
index 6c9507517..c87858f12 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFilterReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayFilterReturnTypeProvider.php
@@ -38,7 +38,7 @@ class ArrayFilterReturnTypeProvider implements \Psalm\Plugin\EventHandler\Functi
             return Type::getMixed();
         }
 
-        $array_arg = isset($call_args[0]->value) ? $call_args[0]->value : null;
+        $array_arg = $call_args[0]->value ?? null;
 
         $first_arg_array = $array_arg
             && ($first_arg_type = $statements_source->node_data->getType($array_arg))
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPointerAdjustmentReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPointerAdjustmentReturnTypeProvider.php
index e4794676f..32d44bd3c 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPointerAdjustmentReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPointerAdjustmentReturnTypeProvider.php
@@ -24,7 +24,7 @@ class ArrayPointerAdjustmentReturnTypeProvider implements \Psalm\Plugin\EventHan
             return Type::getMixed();
         }
 
-        $first_arg = isset($call_args[0]->value) ? $call_args[0]->value : null;
+        $first_arg = $call_args[0]->value ?? null;
 
         if (!$first_arg) {
             return Type::getMixed();
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPopReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPopReturnTypeProvider.php
index 8b4aa693a..33b9321d5 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPopReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayPopReturnTypeProvider.php
@@ -23,7 +23,7 @@ class ArrayPopReturnTypeProvider implements \Psalm\Plugin\EventHandler\FunctionR
             return Type::getMixed();
         }
 
-        $first_arg = isset($call_args[0]->value) ? $call_args[0]->value : null;
+        $first_arg = $call_args[0]->value ?? null;
 
         $first_arg_array = $first_arg
             && ($first_arg_type = $statements_source->node_data->getType($first_arg))
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayRandReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayRandReturnTypeProvider.php
index 8f22be303..8e61ae121 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayRandReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayRandReturnTypeProvider.php
@@ -23,8 +23,8 @@ class ArrayRandReturnTypeProvider implements \Psalm\Plugin\EventHandler\Function
             return Type::getMixed();
         }
 
-        $first_arg = isset($call_args[0]->value) ? $call_args[0]->value : null;
-        $second_arg = isset($call_args[1]->value) ? $call_args[1]->value : null;
+        $first_arg = $call_args[0]->value ?? null;
+        $second_arg = $call_args[1]->value ?? null;
 
         $first_arg_array = $first_arg
             && ($first_arg_type = $statements_source->node_data->getType($first_arg))
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayReduceReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayReduceReturnTypeProvider.php
index 3b38a8bf6..3530237f1 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayReduceReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayReduceReturnTypeProvider.php
@@ -258,11 +258,6 @@ class ArrayReduceReturnTypeProvider implements \Psalm\Plugin\EventHandler\Functi
                                 $method_id,
                                 $self_class
                             ) ?: Type::getMixed();
-
-                            $reduce_return_type = Type::combineUnionTypes(
-                                $reduce_return_type,
-                                $return_type
-                            );
                         } else {
                             if (!$codebase->functions->functionExists(
                                 $statements_source,
@@ -280,12 +275,9 @@ class ArrayReduceReturnTypeProvider implements \Psalm\Plugin\EventHandler\Functi
                             );
 
                             $return_type = $function_storage->return_type ?: Type::getMixed();
-
-                            $reduce_return_type = Type::combineUnionTypes(
-                                $reduce_return_type,
-                                $return_type
-                            );
                         }
+
+                        $reduce_return_type = Type::combineUnionTypes($reduce_return_type, $return_type);
                     }
                 }
 
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArraySliceReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArraySliceReturnTypeProvider.php
index cca2571b8..5b8c90276 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArraySliceReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArraySliceReturnTypeProvider.php
@@ -23,7 +23,7 @@ class ArraySliceReturnTypeProvider implements \Psalm\Plugin\EventHandler\Functio
             return Type::getMixed();
         }
 
-        $first_arg = isset($call_args[0]->value) ? $call_args[0]->value : null;
+        $first_arg = $call_args[0]->value ?? null;
 
         if (!$first_arg) {
             return Type::getArray();
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayValuesReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayValuesReturnTypeProvider.php
index bbea643ac..a6a16a9fe 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayValuesReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayValuesReturnTypeProvider.php
@@ -22,7 +22,7 @@ class ArrayValuesReturnTypeProvider implements \Psalm\Plugin\EventHandler\Functi
             return Type::getMixed();
         }
 
-        $first_arg = isset($call_args[0]->value) ? $call_args[0]->value : null;
+        $first_arg = $call_args[0]->value ?? null;
 
         if (!$first_arg) {
             return Type::getArray();
diff --git a/src/Psalm/Internal/Provider/StatementsProvider.php b/src/Psalm/Internal/Provider/StatementsProvider.php
index 47aed3ef8..d6701770e 100644
--- a/src/Psalm/Internal/Provider/StatementsProvider.php
+++ b/src/Psalm/Internal/Provider/StatementsProvider.php
@@ -14,7 +14,7 @@ use function count;
 use function filemtime;
 use function md5;
 use function strlen;
-use function substr;
+use function strpos;
 
 /**
  * @internal
@@ -227,7 +227,7 @@ class StatementsProvider
 
                 $changed_members = array_map(
                     function (string $key) use ($file_path_hash) : string {
-                        if (substr($key, 0, 4) === 'use:') {
+                        if (strpos($key, 'use:') === 0) {
                             return $key . ':' . $file_path_hash;
                         }
 
diff --git a/src/Psalm/Internal/Scanner/ClassLikeDocblockComment.php b/src/Psalm/Internal/Scanner/ClassLikeDocblockComment.php
index f18f947f5..64f24ad52 100644
--- a/src/Psalm/Internal/Scanner/ClassLikeDocblockComment.php
+++ b/src/Psalm/Internal/Scanner/ClassLikeDocblockComment.php
@@ -32,7 +32,7 @@ class ClassLikeDocblockComment
      *
      * @var null|string
      */
-    public $psalm_internal = null;
+    public $psalm_internal;
 
     /**
      * @var string[]
@@ -57,7 +57,7 @@ class ClassLikeDocblockComment
     /**
      * @var ?string
      */
-    public $yield = null;
+    public $yield;
 
     /**
      * @var array<int, array{name:string, type:string, tag:string, line_number:int}>
diff --git a/src/Psalm/Internal/Scanner/DocblockParser.php b/src/Psalm/Internal/Scanner/DocblockParser.php
index 58e6c8268..aa9a11c30 100644
--- a/src/Psalm/Internal/Scanner/DocblockParser.php
+++ b/src/Psalm/Internal/Scanner/DocblockParser.php
@@ -31,7 +31,7 @@ class DocblockParser
         // Strip off comments.
         $docblock = trim($docblock);
 
-        if (substr($docblock, 0, 3) === '/**') {
+        if (strpos($docblock, '/**') === 0) {
             $docblock = substr($docblock, 3);
         }
 
diff --git a/src/Psalm/Internal/Scanner/FunctionDocblockComment.php b/src/Psalm/Internal/Scanner/FunctionDocblockComment.php
index f3c8fda0a..d0482c10a 100644
--- a/src/Psalm/Internal/Scanner/FunctionDocblockComment.php
+++ b/src/Psalm/Internal/Scanner/FunctionDocblockComment.php
@@ -9,22 +9,22 @@ class FunctionDocblockComment
     /**
      * @var string|null
      */
-    public $return_type = null;
+    public $return_type;
 
     /**
      * @var string|null
      */
-    public $return_type_description = null;
+    public $return_type_description;
 
     /**
      * @var int|null
      */
-    public $return_type_start = null;
+    public $return_type_start;
 
     /**
      * @var int|null
      */
-    public $return_type_end = null;
+    public $return_type_end;
 
     /**
      * @var int|null
@@ -73,7 +73,7 @@ class FunctionDocblockComment
      *
      * @var null|string
      */
-    public $psalm_internal = null;
+    public $psalm_internal;
 
     /**
      * Whether or not the function is internal
diff --git a/src/Psalm/Internal/Scanner/UnresolvedConstant/UnresolvedTernary.php b/src/Psalm/Internal/Scanner/UnresolvedConstant/UnresolvedTernary.php
index 0a675617b..f9618f0ff 100644
--- a/src/Psalm/Internal/Scanner/UnresolvedConstant/UnresolvedTernary.php
+++ b/src/Psalm/Internal/Scanner/UnresolvedConstant/UnresolvedTernary.php
@@ -9,8 +9,11 @@ use Psalm\Internal\Scanner\UnresolvedConstantComponent;
  */
 class UnresolvedTernary extends UnresolvedConstantComponent
 {
+    /** @var UnresolvedConstantComponent */
     public $cond;
+    /** @var UnresolvedConstantComponent|null */
     public $if;
+    /** @var UnresolvedConstantComponent */
     public $else;
 
     public function __construct(
diff --git a/src/Psalm/Internal/Scanner/VarDocblockComment.php b/src/Psalm/Internal/Scanner/VarDocblockComment.php
index fb55108f5..330848f7c 100644
--- a/src/Psalm/Internal/Scanner/VarDocblockComment.php
+++ b/src/Psalm/Internal/Scanner/VarDocblockComment.php
@@ -16,7 +16,7 @@ class VarDocblockComment
     /**
      * @var string|null
      */
-    public $var_id = null;
+    public $var_id;
 
     /**
      * @var int|null
@@ -52,7 +52,7 @@ class VarDocblockComment
      *
      * @var null|string
      */
-    public $psalm_internal = null;
+    public $psalm_internal;
 
     /**
      * Whether or not the property is readonly
diff --git a/src/Psalm/Internal/Scope/IfScope.php b/src/Psalm/Internal/Scope/IfScope.php
index 98ee90741..85fdc515e 100644
--- a/src/Psalm/Internal/Scope/IfScope.php
+++ b/src/Psalm/Internal/Scope/IfScope.php
@@ -12,7 +12,7 @@ class IfScope
     /**
      * @var array<string, Type\Union>|null
      */
-    public $new_vars = null;
+    public $new_vars;
 
     /**
      * @var array<string, bool>
@@ -22,12 +22,12 @@ class IfScope
     /**
      * @var array<string, Type\Union>|null
      */
-    public $redefined_vars = null;
+    public $redefined_vars;
 
     /**
      * @var array<string, int>|null
      */
-    public $assigned_var_ids = null;
+    public $assigned_var_ids;
 
     /**
      * @var array<string, bool>
@@ -57,7 +57,7 @@ class IfScope
     /**
      * @var array<string, string>|null
      */
-    public $negatable_if_types = null;
+    public $negatable_if_types;
 
     /**
      * @var list<Clause>
@@ -78,7 +78,7 @@ class IfScope
      *
      * @var array<string, Type\Union>|null
      */
-    public $possible_param_types = null;
+    public $possible_param_types;
 
     /**
      * @var string[]
diff --git a/src/Psalm/Internal/Scope/LoopScope.php b/src/Psalm/Internal/Scope/LoopScope.php
index 2bbfe903b..1e6204100 100644
--- a/src/Psalm/Internal/Scope/LoopScope.php
+++ b/src/Psalm/Internal/Scope/LoopScope.php
@@ -37,7 +37,7 @@ class LoopScope
     /**
      * @var array<string, Type\Union>|null
      */
-    public $possibly_redefined_loop_parent_vars = null;
+    public $possibly_redefined_loop_parent_vars;
 
     /**
      * @var array<string, Type\Union>
diff --git a/src/Psalm/Internal/Scope/SwitchScope.php b/src/Psalm/Internal/Scope/SwitchScope.php
index 9025e6557..0697d6fab 100644
--- a/src/Psalm/Internal/Scope/SwitchScope.php
+++ b/src/Psalm/Internal/Scope/SwitchScope.php
@@ -13,7 +13,7 @@ class SwitchScope
     /**
      * @var array<string, Type\Union>|null
      */
-    public $new_vars_in_scope = null;
+    public $new_vars_in_scope;
 
     /**
      * @var array<string, bool>
@@ -23,12 +23,12 @@ class SwitchScope
     /**
      * @var array<string, Type\Union>|null
      */
-    public $redefined_vars = null;
+    public $redefined_vars;
 
     /**
      * @var array<string, Type\Union>|null
      */
-    public $possibly_redefined_vars = null;
+    public $possibly_redefined_vars;
 
     /**
      * @var array<PhpParser\Node\Stmt>
@@ -38,7 +38,7 @@ class SwitchScope
     /**
      * @var PhpParser\Node\Expr|null
      */
-    public $leftover_case_equality_expr = null;
+    public $leftover_case_equality_expr;
 
     /**
      * @var list<Clause>
@@ -48,5 +48,5 @@ class SwitchScope
     /**
      * @var array<string, bool>|null
      */
-    public $new_assigned_var_ids = null;
+    public $new_assigned_var_ids;
 }
diff --git a/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php b/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php
index a1044f89d..55d19edca 100644
--- a/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php
+++ b/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php
@@ -16,6 +16,7 @@ use Psalm\Storage\ClassLikeStorage;
 use Psalm\Internal\Analyzer\ClassLikeAnalyzer;
 use Psalm\Internal\Scanner\ParsedDocblock;
 use Psalm\Type;
+use function array_slice;
 
 class ClassLikeStubGenerator
 {
diff --git a/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php b/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php
index e57c180b2..efce50c04 100644
--- a/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php
+++ b/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php
@@ -22,6 +22,7 @@ use Psalm\Node\VirtualName;
 use Psalm\Node\VirtualNullableType;
 use Psalm\Node\VirtualParam;
 use Psalm\Type;
+use function dirname;
 
 class StubsGenerator
 {
diff --git a/src/Psalm/Internal/Type/AssertionReconciler.php b/src/Psalm/Internal/Type/AssertionReconciler.php
index 9daff509c..e7d47ad1a 100644
--- a/src/Psalm/Internal/Type/AssertionReconciler.php
+++ b/src/Psalm/Internal/Type/AssertionReconciler.php
@@ -147,7 +147,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
             return $simply_reconciled_type;
         }
 
-        if (substr($assertion, 0, 4) === 'isa-') {
+        if (strpos($assertion, 'isa-') === 0) {
             $should_return = false;
 
             $new_type = self::handleIsA(
@@ -164,7 +164,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
             if ($should_return) {
                 return $new_type;
             }
-        } elseif (substr($assertion, 0, 9) === 'getclass-') {
+        } elseif (strpos($assertion, 'getclass-') === 0) {
             $assertion = substr($assertion, 9);
             $new_type = Type::parseString($assertion, null, $template_type_map);
         } else {
@@ -1003,7 +1003,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
                     $did_remove_type = false;
 
                     foreach ($existing_var_atomic_types as $atomic_key => $_) {
-                        if (substr($atomic_key, 0, 6) === 'float(') {
+                        if (strpos($atomic_key, 'float(') === 0) {
                             $atomic_key = 'int(' . substr($atomic_key, 6);
                         }
                         if ($atomic_key !== $assertion) {
@@ -1075,7 +1075,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
                         $existing_var_atomic_type->as = self::handleLiteralEquality(
                             $assertion,
                             $bracket_pos,
-                            $is_loose_equality,
+                            false,
                             $existing_var_atomic_type->as,
                             $old_var_type_string,
                             $var_id,
@@ -1211,7 +1211,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
                     $did_remove_type = false;
 
                     foreach ($existing_var_atomic_types as $atomic_key => $_) {
-                        if (substr($atomic_key, 0, 4) === 'int(') {
+                        if (strpos($atomic_key, 'int(') === 0) {
                             $atomic_key = 'float(' . substr($atomic_key, 4);
                         }
                         if ($atomic_key !== $assertion) {
@@ -1240,7 +1240,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
                 }
             }
         } elseif ($scalar_type === 'enum') {
-            list($fq_enum_name, $case_name) = explode('::', $value);
+            [$fq_enum_name, $case_name] = explode('::', $value);
 
             if ($existing_var_type->hasMixed()) {
                 if ($is_loose_equality) {
@@ -1297,7 +1297,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
         Codebase $codebase,
         Union $existing_var_type,
         string &$assertion,
-        array &$template_type_map,
+        array $template_type_map,
         ?CodeLocation $code_location,
         ?string $key,
         array $suppressed_issues,
@@ -1307,7 +1307,7 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
 
         $allow_string_comparison = false;
 
-        if (substr($assertion, 0, 7) === 'string-') {
+        if (strpos($assertion, 'string-') === 0) {
             $assertion = substr($assertion, 7);
             $allow_string_comparison = true;
         }
diff --git a/src/Psalm/Internal/Type/Comparator/CallableTypeComparator.php b/src/Psalm/Internal/Type/Comparator/CallableTypeComparator.php
index 3a0b6227b..26e65fd21 100644
--- a/src/Psalm/Internal/Type/Comparator/CallableTypeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/CallableTypeComparator.php
@@ -321,7 +321,7 @@ class CallableTypeComparator
 
                     $matching_callable->is_pure = $codebase->functions->isCallMapFunctionPure(
                         $codebase,
-                        $statements_analyzer ? $statements_analyzer->node_data : null,
+                        $statements_analyzer->node_data ?? null,
                         $input_type_part->value,
                         null,
                         $must_use
diff --git a/src/Psalm/Internal/Type/Comparator/IntegerRangeComparator.php b/src/Psalm/Internal/Type/Comparator/IntegerRangeComparator.php
index 4fe35a4f9..33607b97c 100644
--- a/src/Psalm/Internal/Type/Comparator/IntegerRangeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/IntegerRangeComparator.php
@@ -81,15 +81,7 @@ class IntegerRangeComparator
             return false;
         }
 
-        if ($result_reduction === null) {
-            //inconclusive result, we can't remove atomics anymore.
-            //container: `int<1, 5>`, input: `int<0, 6>`
-            //container: `5`, input: `int<4, 6>`
-            //we assume there's no combinations that makes the input contained
-            return false;
-        }
-
-        return $result_reduction;
+        return $result_reduction ?? false;
     }
 
     /**
diff --git a/src/Psalm/Internal/Type/Comparator/ObjectComparator.php b/src/Psalm/Internal/Type/Comparator/ObjectComparator.php
index 017ef53e0..22d451e8a 100644
--- a/src/Psalm/Internal/Type/Comparator/ObjectComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/ObjectComparator.php
@@ -76,11 +76,11 @@ class ObjectComparator
 
                     foreach ($intersection_input_types as $intersection_input_type) {
                         if ($intersection_input_type instanceof TTemplateParam
-                            && (\substr($intersection_container_type->defining_class, 0, 3) === 'fn-'
-                                || \substr($intersection_input_type->defining_class, 0, 3) === 'fn-')
+                            && (\strpos($intersection_container_type->defining_class, 'fn-') === 0
+                                || \strpos($intersection_input_type->defining_class, 'fn-') === 0)
                         ) {
-                            if (\substr($intersection_input_type->defining_class, 0, 3) === 'fn-'
-                                && \substr($intersection_container_type->defining_class, 0, 3) === 'fn-'
+                            if (\strpos($intersection_input_type->defining_class, 'fn-') === 0
+                                && \strpos($intersection_container_type->defining_class, 'fn-') === 0
                                 && $intersection_input_type->defining_class
                                     !== $intersection_container_type->defining_class
                             ) {
@@ -191,10 +191,10 @@ class ObjectComparator
                     if ($intersection_container_type->param_name !== $intersection_input_type->param_name
                         || ($intersection_container_type->defining_class
                             !== $intersection_input_type->defining_class
-                            && \substr($intersection_input_type->defining_class, 0, 3) !== 'fn-'
-                            && \substr($intersection_container_type->defining_class, 0, 3) !== 'fn-')
+                            && \strpos($intersection_input_type->defining_class, 'fn-') !== 0
+                            && \strpos($intersection_container_type->defining_class, 'fn-') !== 0)
                     ) {
-                        if (\substr($intersection_input_type->defining_class, 0, 3) !== 'fn-') {
+                        if (\strpos($intersection_input_type->defining_class, 'fn-') !== 0) {
                             $input_class_storage = $codebase->classlike_storage_provider->get(
                                 $intersection_input_type->defining_class
                             );
diff --git a/src/Psalm/Internal/Type/Comparator/TypeComparisonResult.php b/src/Psalm/Internal/Type/Comparator/TypeComparisonResult.php
index 78f269873..288da07b9 100644
--- a/src/Psalm/Internal/Type/Comparator/TypeComparisonResult.php
+++ b/src/Psalm/Internal/Type/Comparator/TypeComparisonResult.php
@@ -5,26 +5,26 @@ namespace Psalm\Internal\Type\Comparator;
 class TypeComparisonResult
 {
     /** @var ?bool */
-    public $scalar_type_match_found = null;
+    public $scalar_type_match_found;
 
     /** @var ?bool */
-    public $type_coerced = null;
+    public $type_coerced;
 
     /** @var ?bool */
-    public $type_coerced_from_mixed = null;
+    public $type_coerced_from_mixed;
 
     /** @var ?bool */
-    public $type_coerced_from_as_mixed = null;
+    public $type_coerced_from_as_mixed;
 
     /** @var ?bool */
-    public $to_string_cast = null;
+    public $to_string_cast;
 
     /** @var ?bool */
-    public $type_coerced_from_scalar = null;
+    public $type_coerced_from_scalar;
 
     /** @var ?\Psalm\Type\Union */
-    public $replacement_union_type = null;
+    public $replacement_union_type;
 
     /** @var ?\Psalm\Type\Atomic */
-    public $replacement_atomic_type = null;
+    public $replacement_atomic_type;
 }
diff --git a/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php b/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
index 622047b47..12eb39ea7 100644
--- a/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
@@ -381,7 +381,7 @@ class UnionTypeComparator
             }
         }
 
-        return !!$matching_input_keys;
+        return (bool)$matching_input_keys;
     }
 
     /**
diff --git a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
index 8a0d68787..164d21399 100644
--- a/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/NegatedAssertionReconciler.php
@@ -159,7 +159,7 @@ class NegatedAssertionReconciler extends Reconciler
                 return Type::getEmpty();
             }
 
-            if (substr($assertion, 0, 9) === 'in-array-') {
+            if (strpos($assertion, 'in-array-') === 0) {
                 $assertion = substr($assertion, 9);
                 $new_var_type = null;
                 try {
@@ -195,7 +195,7 @@ class NegatedAssertionReconciler extends Reconciler
                 return $existing_var_type;
             }
 
-            if (substr($assertion, 0, 14) === 'has-array-key-') {
+            if (strpos($assertion, 'has-array-key-') === 0) {
                 return $existing_var_type;
             }
         }
@@ -283,7 +283,7 @@ class NegatedAssertionReconciler extends Reconciler
         ) {
             $existing_var_type->removeType('array-key');
             $existing_var_type->addType(new TString);
-        } elseif (substr($assertion, 0, 9) === 'getclass-') {
+        } elseif (strpos($assertion, 'getclass-') === 0) {
             $assertion = substr($assertion, 9);
         } elseif (!$is_equality) {
             $codebase = $statements_analyzer->getCodebase();
@@ -462,7 +462,7 @@ class NegatedAssertionReconciler extends Reconciler
                 $scalar_var_type = Type::getFloat((float) $scalar_value);
             }
         } elseif ($scalar_type === 'enum') {
-            list($fq_enum_name, $case_name) = explode('::', substr($assertion, $bracket_pos + 1, -1));
+            [$fq_enum_name, $case_name] = explode('::', substr($assertion, $bracket_pos + 1, -1));
 
             foreach ($existing_var_type->getAtomicTypes() as $atomic_key => $atomic_type) {
                 if (get_class($atomic_type) === Type\Atomic\TNamedObject::class
diff --git a/src/Psalm/Internal/Type/ParseTreeCreator.php b/src/Psalm/Internal/Type/ParseTreeCreator.php
index 4c70e4ff3..95b812274 100644
--- a/src/Psalm/Internal/Type/ParseTreeCreator.php
+++ b/src/Psalm/Internal/Type/ParseTreeCreator.php
@@ -402,10 +402,8 @@ class ParseTreeCreator
             $this->current_leaf->parent = $new_leaf;
 
             array_pop($current_parent->children);
-            $current_parent->children[] = $new_leaf;
-        } else {
-            $current_parent->children[] = $new_leaf;
         }
+        $current_parent->children[] = $new_leaf;
 
         $this->current_leaf = $new_leaf;
     }
@@ -450,7 +448,7 @@ class ParseTreeCreator
             return;
         }
 
-        if ($current_parent && $current_parent instanceof ParseTree\KeyedArrayPropertyTree) {
+        if ($current_parent instanceof ParseTree\KeyedArrayPropertyTree) {
             return;
         }
 
@@ -462,7 +460,7 @@ class ParseTreeCreator
             $current_parent = $this->current_leaf->parent;
         }
 
-        if ($current_parent && $current_parent instanceof ParseTree\ConditionalTree) {
+        if ($current_parent instanceof ParseTree\ConditionalTree) {
             if (count($current_parent->children) > 1) {
                 throw new TypeParseTreeException('Cannot process colon in conditional twice');
             }
@@ -608,12 +606,12 @@ class ParseTreeCreator
             throw new TypeParseTreeException('Unexpected token |');
         }
 
-        if ($current_parent && $current_parent instanceof ParseTree\UnionTree) {
+        if ($current_parent instanceof ParseTree\UnionTree) {
             $this->current_leaf = $current_parent;
             return;
         }
 
-        if ($current_parent && $current_parent instanceof ParseTree\IntersectionTree) {
+        if ($current_parent instanceof ParseTree\IntersectionTree) {
             $this->current_leaf = $current_parent;
             $current_parent = $this->current_leaf->parent;
         }
@@ -649,12 +647,12 @@ class ParseTreeCreator
 
         $current_parent = $this->current_leaf->parent;
 
-        if ($current_parent && $current_parent instanceof ParseTree\MethodTree) {
+        if ($current_parent instanceof ParseTree\MethodTree) {
             $this->createMethodParam($this->type_tokens[$this->t], $current_parent);
             return;
         }
 
-        if ($current_parent && $current_parent instanceof ParseTree\IntersectionTree) {
+        if ($current_parent instanceof ParseTree\IntersectionTree) {
             $this->current_leaf = $current_parent;
             return;
         }
diff --git a/src/Psalm/Internal/Type/SimpleAssertionReconciler.php b/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
index d57453eda..d757708d8 100644
--- a/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
@@ -87,7 +87,7 @@ class SimpleAssertionReconciler extends \Psalm\Type\Reconciler
             return $existing_var_type;
         }
 
-        if (substr($assertion, 0, 9) === 'in-array-') {
+        if (strpos($assertion, 'in-array-') === 0) {
             return self::reconcileInArray(
                 $codebase,
                 $existing_var_type,
@@ -100,7 +100,7 @@ class SimpleAssertionReconciler extends \Psalm\Type\Reconciler
             );
         }
 
-        if (substr($assertion, 0, 14) === 'has-array-key-') {
+        if (strpos($assertion, 'has-array-key-') === 0) {
             return self::reconcileHasArrayKey(
                 $existing_var_type,
                 substr($assertion, 14)
@@ -369,7 +369,7 @@ class SimpleAssertionReconciler extends \Psalm\Type\Reconciler
             );
         }
 
-        if (substr($assertion, 0, 13) === 'has-at-least-') {
+        if (strpos($assertion, 'has-at-least-') === 0) {
             return self::reconcileNonEmptyCountable(
                 $existing_var_type,
                 $key,
@@ -382,7 +382,7 @@ class SimpleAssertionReconciler extends \Psalm\Type\Reconciler
             );
         }
 
-        if (substr($assertion, 0, 12) === 'has-exactly-') {
+        if (strpos($assertion, 'has-exactly-') === 0) {
             /** @psalm-suppress ArgumentTypeCoercion */
             return self::reconcileExactlyCountable(
                 $existing_var_type,
@@ -390,7 +390,7 @@ class SimpleAssertionReconciler extends \Psalm\Type\Reconciler
             );
         }
 
-        if (substr($assertion, 0, 10) === 'hasmethod-') {
+        if (strpos($assertion, 'hasmethod-') === 0) {
             return self::reconcileHasMethod(
                 $codebase,
                 substr($assertion, 10),
diff --git a/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php b/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
index ab6b41e09..9ea23e96c 100644
--- a/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
@@ -29,6 +29,7 @@ use Psalm\Type\Union;
 
 use function get_class;
 use function max;
+use function strpos;
 use function substr;
 
 class SimpleNegatedAssertionReconciler extends Reconciler
@@ -217,7 +218,7 @@ class SimpleNegatedAssertionReconciler extends Reconciler
             );
         }
 
-        if (substr($assertion, 0, 13) === 'has-at-least-') {
+        if (strpos($assertion, 'has-at-least-') === 0) {
             return self::reconcileNonEmptyCountable(
                 $existing_var_type,
                 $key,
@@ -230,7 +231,7 @@ class SimpleNegatedAssertionReconciler extends Reconciler
             );
         }
 
-        if (substr($assertion, 0, 12) === 'has-exactly-') {
+        if (strpos($assertion, 'has-exactly-') === 0) {
             return $existing_var_type;
         }
 
diff --git a/src/Psalm/Internal/Type/TemplateInferredTypeReplacer.php b/src/Psalm/Internal/Type/TemplateInferredTypeReplacer.php
index a1cd6fdff..cc92d0430 100644
--- a/src/Psalm/Internal/Type/TemplateInferredTypeReplacer.php
+++ b/src/Psalm/Internal/Type/TemplateInferredTypeReplacer.php
@@ -14,7 +14,7 @@ use Psalm\Type\Union;
 use function array_merge;
 use function array_shift;
 use function array_values;
-use function substr;
+use function strpos;
 
 class TemplateInferredTypeReplacer
 {
@@ -83,7 +83,7 @@ class TemplateInferredTypeReplacer
                 } elseif ($codebase) {
                     foreach ($inferred_lower_bounds as $template_type_map) {
                         foreach ($template_type_map as $template_class => $_) {
-                            if (substr($template_class, 0, 3) === 'fn-') {
+                            if (strpos($template_class, 'fn-') === 0) {
                                 continue;
                             }
 
diff --git a/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php b/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
index b07073017..5223e1126 100644
--- a/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
+++ b/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
@@ -179,7 +179,7 @@ class TemplateStandinTypeReplacer
                     $template_result,
                     $codebase,
                     $statements_analyzer,
-                    $replace,
+                    true,
                     $add_lower_bound,
                     $bound_equality_classlike,
                     $depth,
@@ -599,7 +599,7 @@ class TemplateStandinTypeReplacer
                         $input_arg_offset,
                         $calling_class,
                         $calling_function,
-                        $replace,
+                        true,
                         $add_lower_bound,
                         $bound_equality_classlike,
                         $depth + 1
@@ -685,7 +685,7 @@ class TemplateStandinTypeReplacer
                 $input_arg_offset,
                 $calling_class,
                 $calling_function,
-                $replace,
+                true,
                 $add_lower_bound,
                 $bound_equality_classlike,
                 $depth + 1
@@ -1174,11 +1174,7 @@ class TemplateStandinTypeReplacer
                                 \array_keys($input_class_storage->template_types)
                             );
 
-                            if (!isset($input_type_params[$old_params_offset])) {
-                                $candidate_param_type = \Psalm\Type::getMixed();
-                            } else {
-                                $candidate_param_type = $input_type_params[$old_params_offset];
-                            }
+                            $candidate_param_type = $input_type_params[$old_params_offset] ?? \Psalm\Type::getMixed();
                         } else {
                             $candidate_param_type = new Union([clone $et]);
                         }
diff --git a/src/Psalm/Internal/Type/TypeCombination.php b/src/Psalm/Internal/Type/TypeCombination.php
index f2fd1dcc6..5bcb88e95 100644
--- a/src/Psalm/Internal/Type/TypeCombination.php
+++ b/src/Psalm/Internal/Type/TypeCombination.php
@@ -46,10 +46,10 @@ class TypeCombination
     public $objectlike_sealed = true;
 
     /** @var ?Union */
-    public $objectlike_key_type = null;
+    public $objectlike_key_type;
 
     /** @var ?Union */
-    public $objectlike_value_type = null;
+    public $objectlike_value_type;
 
     /** @var bool */
     public $empty_mixed = false;
@@ -58,7 +58,7 @@ class TypeCombination
     public $non_empty_mixed = false;
 
     /** @var ?bool */
-    public $mixed_from_loop_isset = null;
+    public $mixed_from_loop_isset;
 
     /** @var array<string, Atomic\TLiteralString>|null */
     public $strings = [];
diff --git a/src/Psalm/Internal/Type/TypeCombiner.php b/src/Psalm/Internal/Type/TypeCombiner.php
index 320ebc0f3..8c86dd9c7 100644
--- a/src/Psalm/Internal/Type/TypeCombiner.php
+++ b/src/Psalm/Internal/Type/TypeCombiner.php
@@ -684,9 +684,7 @@ class TypeCombiner
             $has_defined_keys = false;
 
             foreach ($type->properties as $candidate_property_name => $candidate_property_type) {
-                $value_type = isset($combination->objectlike_entries[$candidate_property_name])
-                    ? $combination->objectlike_entries[$candidate_property_name]
-                    : null;
+                $value_type = $combination->objectlike_entries[$candidate_property_name] ?? null;
 
                 if (!$value_type) {
                     $combination->objectlike_entries[$candidate_property_name] = clone $candidate_property_type;
diff --git a/src/Psalm/Internal/Type/TypeExpander.php b/src/Psalm/Internal/Type/TypeExpander.php
index b61735e05..e7123c461 100644
--- a/src/Psalm/Internal/Type/TypeExpander.php
+++ b/src/Psalm/Internal/Type/TypeExpander.php
@@ -664,7 +664,7 @@ class TypeExpander
         bool $evaluate_class_constants = true,
         bool $evaluate_conditional_types = false,
         bool $final = false,
-        bool &$expand_generic = false,
+        bool $expand_generic = false,
         bool $expand_templates = false
     ) {
         $new_as_type = self::expandUnion(
diff --git a/src/Psalm/Internal/Type/TypeParser.php b/src/Psalm/Internal/Type/TypeParser.php
index 77100f9fa..ab0da4d45 100644
--- a/src/Psalm/Internal/Type/TypeParser.php
+++ b/src/Psalm/Internal/Type/TypeParser.php
@@ -406,7 +406,7 @@ class TypeParser
 
                 return new Atomic\TTemplateParamClass(
                     $t->param_name,
-                    $t_atomic_type ? $t_atomic_type->value : 'object',
+                    $t_atomic_type->value ?? 'object',
                     $t_atomic_type,
                     $t->defining_class
                 );
@@ -1183,7 +1183,7 @@ class TypeParser
         $array_defining_class = array_keys($template_type_map[$array_param_name])[0];
 
         if ($offset_defining_class !== $array_defining_class
-            && substr($offset_defining_class, 0, 3) !== 'fn-'
+            && strpos($offset_defining_class, 'fn-') !== 0
         ) {
             throw new TypeParseTreeException('Template params are defined in different locations');
         }
diff --git a/src/Psalm/Internal/Type/TypeTokenizer.php b/src/Psalm/Internal/Type/TypeTokenizer.php
index bb74404a2..204361bf8 100644
--- a/src/Psalm/Internal/Type/TypeTokenizer.php
+++ b/src/Psalm/Internal/Type/TypeTokenizer.php
@@ -4,7 +4,6 @@ namespace Psalm\Internal\Type;
 use Psalm\Aliases;
 use Psalm\Exception\TypeParseTreeException;
 
-use function array_push;
 use function array_splice;
 use function array_unshift;
 use function count;
@@ -479,7 +478,7 @@ class TypeTokenizer
                     $replacement_tokens = $type_alias->replacement_tokens;
 
                     array_unshift($replacement_tokens, ['(', $i]);
-                    array_push($replacement_tokens, [')', $i]);
+                    $replacement_tokens[] = [')', $i];
 
                     $diff = count($replacement_tokens) - 1;
 
diff --git a/src/Psalm/Internal/TypeVisitor/TypeChecker.php b/src/Psalm/Internal/TypeVisitor/TypeChecker.php
index 3993d8567..d402cbd01 100644
--- a/src/Psalm/Internal/TypeVisitor/TypeChecker.php
+++ b/src/Psalm/Internal/TypeVisitor/TypeChecker.php
@@ -355,7 +355,7 @@ class TypeChecker extends NodeVisitor
     public function checkTemplateParam(\Psalm\Type\Atomic\TTemplateParam $atomic) : void
     {
         if ($this->prevent_template_covariance
-            && \substr($atomic->defining_class, 0, 3) !== 'fn-'
+            && \strpos($atomic->defining_class, 'fn-') !== 0
         ) {
             $codebase = $this->source->getCodebase();
 
diff --git a/src/Psalm/Issue/CodeIssue.php b/src/Psalm/Issue/CodeIssue.php
index 3d64cfc4d..871b89d47 100644
--- a/src/Psalm/Issue/CodeIssue.php
+++ b/src/Psalm/Issue/CodeIssue.php
@@ -2,11 +2,9 @@
 namespace Psalm\Issue;
 
 use Psalm\CodeLocation;
-use Psalm\Config;
 
 use function array_pop;
 use function explode;
-use function get_called_class;
 
 abstract class CodeIssue
 {
@@ -87,13 +85,13 @@ abstract class CodeIssue
         return $this->message;
     }
 
-    public function toIssueData(string $severity = Config::REPORT_ERROR): \Psalm\Internal\Analyzer\IssueData
+    public function toIssueData(string $severity): \Psalm\Internal\Analyzer\IssueData
     {
         $location = $this->code_location;
         $selection_bounds = $location->getSelectionBounds();
         $snippet_bounds = $location->getSnippetBounds();
 
-        $fqcn_parts = explode('\\', get_called_class());
+        $fqcn_parts = explode('\\', static::class);
         $issue_type = array_pop($fqcn_parts);
 
         return new \Psalm\Internal\Analyzer\IssueData(
diff --git a/src/Psalm/IssueBuffer.php b/src/Psalm/IssueBuffer.php
index e07d60bab..9b773d485 100644
--- a/src/Psalm/IssueBuffer.php
+++ b/src/Psalm/IssueBuffer.php
@@ -115,7 +115,7 @@ class IssueBuffer
 
     public static function addUnusedSuppression(string $file_path, int $offset, string $issue_type) : void
     {
-        if (\substr($issue_type, 0, 7) === 'Tainted') {
+        if (\strpos($issue_type, 'Tainted') === 0) {
             return;
         }
 
@@ -215,7 +215,7 @@ class IssueBuffer
             return false;
         }
 
-        $is_tainted = \substr($issue_type, 0, 7) === 'Tainted';
+        $is_tainted = \strpos($issue_type, 'Tainted') === 0;
 
         if ($project_analyzer->getCodebase()->taint_flow_graph && !$is_tainted) {
             return false;
@@ -531,12 +531,12 @@ class IssueBuffer
                                 if ($position !== false) {
                                     $issue_data->severity = Config::REPORT_INFO;
                                     array_splice($issue_baseline[$file][$type]['s'], $position, 1);
-                                    $issue_baseline[$file][$type]['o'] = $issue_baseline[$file][$type]['o'] - 1;
+                                    $issue_baseline[$file][$type]['o']--;
                                 }
                             } else {
                                 $issue_baseline[$file][$type]['s'] = [];
                                 $issue_data->severity = Config::REPORT_INFO;
-                                $issue_baseline[$file][$type]['o'] = $issue_baseline[$file][$type]['o'] - 1;
+                                $issue_baseline[$file][$type]['o']--;
                             }
                         }
 
diff --git a/src/Psalm/Progress/Progress.php b/src/Psalm/Progress/Progress.php
index 7bf84b561..06c4efd52 100644
--- a/src/Psalm/Progress/Progress.php
+++ b/src/Psalm/Progress/Progress.php
@@ -54,7 +54,7 @@ abstract class Progress
 
     protected static function doesTerminalSupportUtf8() : bool
     {
-        if (\strtoupper(\substr(PHP_OS, 0, 3)) === 'WIN') {
+        if (\stripos(PHP_OS, 'WIN') === 0) {
             if (!\function_exists('sapi_windows_cp_is_utf8') || !\sapi_windows_cp_is_utf8()) {
                 return false;
             }
diff --git a/src/Psalm/Report.php b/src/Psalm/Report.php
index 68cbc331b..a57b2d304 100644
--- a/src/Psalm/Report.php
+++ b/src/Psalm/Report.php
@@ -105,7 +105,7 @@ abstract class Report
 
     protected function xmlEncode(string $data): string
     {
-        return htmlspecialchars($data, ENT_XML1 | ENT_QUOTES, 'UTF-8');
+        return htmlspecialchars($data, ENT_XML1 | ENT_QUOTES);
     }
 
     abstract public function create(): string;
diff --git a/src/Psalm/Report/PylintReport.php b/src/Psalm/Report/PylintReport.php
index 1e1041dd5..d96354c6e 100644
--- a/src/Psalm/Report/PylintReport.php
+++ b/src/Psalm/Report/PylintReport.php
@@ -36,14 +36,12 @@ class PylintReport extends Report
         // but it's still useful for users.
         // E.g. jenkins can't parse %s:%d:%d.
         $message = sprintf('%s (column %d)', $message, $issue_data->column_from);
-        $issue_string = sprintf(
+        return sprintf(
             '%s:%d: [%s] %s',
             $issue_data->file_name,
             $issue_data->line_from,
             $code,
             $message
         );
-
-        return $issue_string;
     }
 }
diff --git a/src/Psalm/Report/SarifReport.php b/src/Psalm/Report/SarifReport.php
index 6a1e41378..b63e4cb38 100644
--- a/src/Psalm/Report/SarifReport.php
+++ b/src/Psalm/Report/SarifReport.php
@@ -45,7 +45,7 @@ class SarifReport extends Report
                 ],
                 'properties' => [
                     'tags' => [
-                        (\substr($issue_data->type, 0, 7) === 'Tainted') ? 'security' : 'maintainability',
+                        (\strpos($issue_data->type, 'Tainted') === 0) ? 'security' : 'maintainability',
                     ],
                 ],
                 'helpUri' => $issue_data->link,
diff --git a/src/Psalm/Storage/ClassConstantStorage.php b/src/Psalm/Storage/ClassConstantStorage.php
index 2185f6a80..ac752dc10 100644
--- a/src/Psalm/Storage/ClassConstantStorage.php
+++ b/src/Psalm/Storage/ClassConstantStorage.php
@@ -30,7 +30,7 @@ class ClassConstantStorage
     /**
      * @var ?\Psalm\Internal\Scanner\UnresolvedConstantComponent
      */
-    public $unresolved_node = null;
+    public $unresolved_node;
 
     /**
      * @var bool
diff --git a/src/Psalm/Storage/ClassLikeStorage.php b/src/Psalm/Storage/ClassLikeStorage.php
index bf1164115..c7a533e96 100644
--- a/src/Psalm/Storage/ClassLikeStorage.php
+++ b/src/Psalm/Storage/ClassLikeStorage.php
@@ -54,7 +54,7 @@ class ClassLikeStorage
     /**
      * @var ?string
      */
-    public $mixin_declaring_fqcln = null;
+    public $mixin_declaring_fqcln;
 
     /**
      * @var bool
diff --git a/src/Psalm/Storage/FunctionLikeStorage.php b/src/Psalm/Storage/FunctionLikeStorage.php
index 5a1fe6abf..fdef5d4ea 100644
--- a/src/Psalm/Storage/FunctionLikeStorage.php
+++ b/src/Psalm/Storage/FunctionLikeStorage.php
@@ -242,7 +242,7 @@ abstract class FunctionLikeStorage
         return $this->getSignature(false);
     }
 
-    public function getSignature(bool $allow_newlines = false): string
+    public function getSignature(bool $allow_newlines): string
     {
         $newlines = $allow_newlines && !empty($this->params);
 
diff --git a/src/Psalm/Storage/MethodStorage.php b/src/Psalm/Storage/MethodStorage.php
index 7591f18b9..becfc51d4 100644
--- a/src/Psalm/Storage/MethodStorage.php
+++ b/src/Psalm/Storage/MethodStorage.php
@@ -83,12 +83,12 @@ class MethodStorage extends FunctionLikeStorage
     /**
      * @var ?array<string, bool>
      */
-    public $this_property_mutations = null;
+    public $this_property_mutations;
 
     /**
      * @var Type\Union|null
      */
-    public $self_out_type = null;
+    public $self_out_type;
 
     /**
      * @var bool
diff --git a/src/Psalm/Storage/PropertyStorage.php b/src/Psalm/Storage/PropertyStorage.php
index 66917c336..2452f2b0c 100644
--- a/src/Psalm/Storage/PropertyStorage.php
+++ b/src/Psalm/Storage/PropertyStorage.php
@@ -84,7 +84,7 @@ class PropertyStorage
     /**
      * @var ?string
      */
-    public $getter_method = null;
+    public $getter_method;
 
     /**
      * @var bool
diff --git a/src/Psalm/Type/Atomic.php b/src/Psalm/Type/Atomic.php
index 9b6e7c92d..88d9a286c 100644
--- a/src/Psalm/Type/Atomic.php
+++ b/src/Psalm/Type/Atomic.php
@@ -56,7 +56,6 @@ use function get_class;
 use function is_numeric;
 use function strpos;
 use function strtolower;
-use function substr;
 
 abstract class Atomic implements TypeNode
 {
@@ -289,7 +288,7 @@ abstract class Atomic implements TypeNode
                 return new TNonEmptyMixed();
         }
 
-        if (strpos($value, '-') && substr($value, 0, 4) !== 'OCI-') {
+        if (strpos($value, '-') && strpos($value, 'OCI-') !== 0) {
             throw new \Psalm\Exception\TypeParseTreeException('Unrecognized type ' . $value);
         }
 
diff --git a/src/Psalm/Type/Atomic/TCallableArray.php b/src/Psalm/Type/Atomic/TCallableArray.php
index aa484aa89..6edaa611c 100644
--- a/src/Psalm/Type/Atomic/TCallableArray.php
+++ b/src/Psalm/Type/Atomic/TCallableArray.php
@@ -10,9 +10,4 @@ class TCallableArray extends TNonEmptyArray
      * @var string
      */
     public $value = 'callable-array';
-
-    public function getKey(bool $include_extra = true): string
-    {
-        return 'array';
-    }
 }
diff --git a/src/Psalm/Type/Atomic/TClassStringMap.php b/src/Psalm/Type/Atomic/TClassStringMap.php
index acef988c7..70e3b0546 100644
--- a/src/Psalm/Type/Atomic/TClassStringMap.php
+++ b/src/Psalm/Type/Atomic/TClassStringMap.php
@@ -92,7 +92,7 @@ class TClassStringMap extends \Psalm\Type\Atomic
                     $namespace,
                     $aliased_classes,
                     $this_class,
-                    $use_phpdoc_format
+                    true
                 );
         }
 
@@ -106,7 +106,7 @@ class TClassStringMap extends \Psalm\Type\Atomic
                 $namespace,
                 $aliased_classes,
                 $this_class,
-                $use_phpdoc_format
+                false
             )
             . '>';
     }
@@ -234,7 +234,7 @@ class TClassStringMap extends \Psalm\Type\Atomic
         return new Type\Union([
             new TTemplateParamClass(
                 $this->param_name,
-                $this->as_type ? $this->as_type->value : 'object',
+                $this->as_type->value ?? 'object',
                 $this->as_type,
                 'class-string-map'
             )
diff --git a/src/Psalm/Type/Atomic/TEnumCase.php b/src/Psalm/Type/Atomic/TEnumCase.php
index 9e3815c55..0c0f99a5a 100644
--- a/src/Psalm/Type/Atomic/TEnumCase.php
+++ b/src/Psalm/Type/Atomic/TEnumCase.php
@@ -13,7 +13,7 @@ class TEnumCase extends TNamedObject
 
     public function __construct(string $fq_enum_name, string $case_name)
     {
-        parent::__construct($fq_enum_name, false);
+        parent::__construct($fq_enum_name);
 
         $this->case_name = $case_name;
     }
diff --git a/src/Psalm/Type/Atomic/TGenericObject.php b/src/Psalm/Type/Atomic/TGenericObject.php
index 4d0b8c755..20e4e31f3 100644
--- a/src/Psalm/Type/Atomic/TGenericObject.php
+++ b/src/Psalm/Type/Atomic/TGenericObject.php
@@ -69,7 +69,7 @@ class TGenericObject extends TNamedObject
         int $php_major_version,
         int $php_minor_version
     ): ?string {
-        return parent::toNamespacedString($namespace, $aliased_classes, $this_class, false);
+        return $this->toNamespacedString($namespace, $aliased_classes, $this_class, false);
     }
 
     public function equals(Atomic $other_type, bool $ensure_source_equality): bool
@@ -98,6 +98,6 @@ class TGenericObject extends TNamedObject
 
     public function getChildNodes() : array
     {
-        return array_merge($this->type_params, $this->extra_types !== null ? $this->extra_types : []);
+        return array_merge($this->type_params, $this->extra_types ?? []);
     }
 }
diff --git a/src/Psalm/Type/Atomic/TIntMask.php b/src/Psalm/Type/Atomic/TIntMask.php
index c7db8aa42..abb1e0cbf 100644
--- a/src/Psalm/Type/Atomic/TIntMask.php
+++ b/src/Psalm/Type/Atomic/TIntMask.php
@@ -40,19 +40,6 @@ class TIntMask extends TInt
         return 'int-mask<' . substr($s, 0, -2) . '>';
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return $php_major_version >= 7 ? 'int' : null;
-    }
-
     /**
      * @param  array<lowercase-string, string> $aliased_classes
      *
@@ -70,7 +57,7 @@ class TIntMask extends TInt
         $s = '';
 
         foreach ($this->values as $value) {
-            $s .= $value->toNamespacedString($namespace, $aliased_classes, $this_class, $use_phpdoc_format) . ', ';
+            $s .= $value->toNamespacedString($namespace, $aliased_classes, $this_class, false) . ', ';
         }
 
         return 'int-mask<' . substr($s, 0, -2) . '>';
diff --git a/src/Psalm/Type/Atomic/TIntMaskOf.php b/src/Psalm/Type/Atomic/TIntMaskOf.php
index 27e3f80a5..de4f36c29 100644
--- a/src/Psalm/Type/Atomic/TIntMaskOf.php
+++ b/src/Psalm/Type/Atomic/TIntMaskOf.php
@@ -29,19 +29,6 @@ class TIntMaskOf extends TInt
         return $this->getKey();
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return $php_major_version >= 7 ? 'int' : null;
-    }
-
     /**
      * @param array<lowercase-string, string> $aliased_classes
      */
diff --git a/src/Psalm/Type/Atomic/TIntRange.php b/src/Psalm/Type/Atomic/TIntRange.php
index c8e9cd35d..0f8032e38 100644
--- a/src/Psalm/Type/Atomic/TIntRange.php
+++ b/src/Psalm/Type/Atomic/TIntRange.php
@@ -9,8 +9,8 @@ use function min;
  */
 class TIntRange extends TInt
 {
-    const BOUND_MIN = 'min';
-    const BOUND_MAX = 'max';
+    public const BOUND_MIN = 'min';
+    public const BOUND_MAX = 'max';
 
     /**
      * @var int|null
@@ -42,19 +42,6 @@ class TIntRange extends TInt
         return false;
     }
 
-    /**
-     * @param array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return $php_major_version >= 7 ? 'int' : null;
-    }
-
     /**
      * @param array<lowercase-string, string> $aliased_classes
      */
diff --git a/src/Psalm/Type/Atomic/TIterable.php b/src/Psalm/Type/Atomic/TIterable.php
index c00215c66..9169cee9e 100644
--- a/src/Psalm/Type/Atomic/TIterable.php
+++ b/src/Psalm/Type/Atomic/TIterable.php
@@ -121,6 +121,6 @@ class TIterable extends Atomic
 
     public function getChildNodes() : array
     {
-        return array_merge($this->type_params, $this->extra_types !== null ? $this->extra_types : []);
+        return array_merge($this->type_params, $this->extra_types ?? []);
     }
 }
diff --git a/src/Psalm/Type/Atomic/TKeyedArray.php b/src/Psalm/Type/Atomic/TKeyedArray.php
index 1ec5c0ff3..8563f0944 100644
--- a/src/Psalm/Type/Atomic/TKeyedArray.php
+++ b/src/Psalm/Type/Atomic/TKeyedArray.php
@@ -32,7 +32,7 @@ class TKeyedArray extends \Psalm\Type\Atomic
     /**
      * @var array<string, bool>|null
      */
-    public $class_strings = null;
+    public $class_strings;
 
     /**
      * @var bool - whether or not the objectlike has been created from an explicit array
@@ -44,14 +44,14 @@ class TKeyedArray extends \Psalm\Type\Atomic
      *
      * @var ?Union
      */
-    public $previous_key_type = null;
+    public $previous_key_type;
 
     /**
      * Whether or not to allow new properties to be asserted on the given array
      *
      * @var ?Union
      */
-    public $previous_value_type = null;
+    public $previous_value_type;
 
     /**
      * @var bool - if this is a list of sequential elements
@@ -147,7 +147,7 @@ class TKeyedArray extends \Psalm\Type\Atomic
                 $namespace,
                 $aliased_classes,
                 $this_class,
-                $use_phpdoc_format
+                true
             );
         }
 
diff --git a/src/Psalm/Type/Atomic/TList.php b/src/Psalm/Type/Atomic/TList.php
index 50a319aa8..05781ad09 100644
--- a/src/Psalm/Type/Atomic/TList.php
+++ b/src/Psalm/Type/Atomic/TList.php
@@ -68,7 +68,7 @@ class TList extends \Psalm\Type\Atomic
                     $namespace,
                     $aliased_classes,
                     $this_class,
-                    $use_phpdoc_format
+                    true
                 );
         }
 
@@ -79,7 +79,7 @@ class TList extends \Psalm\Type\Atomic
                 $namespace,
                 $aliased_classes,
                 $this_class,
-                $use_phpdoc_format
+                false
             )
             . '>';
     }
diff --git a/src/Psalm/Type/Atomic/TLiteralFloat.php b/src/Psalm/Type/Atomic/TLiteralFloat.php
index 062603803..7b2ce34a8 100644
--- a/src/Psalm/Type/Atomic/TLiteralFloat.php
+++ b/src/Psalm/Type/Atomic/TLiteralFloat.php
@@ -24,19 +24,6 @@ class TLiteralFloat extends TFloat
         return 'float(' . $this->value . ')';
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return $php_major_version >= 7 ? 'float' : null;
-    }
-
     /**
      * @param  array<lowercase-string, string> $aliased_classes
      *
diff --git a/src/Psalm/Type/Atomic/TLiteralInt.php b/src/Psalm/Type/Atomic/TLiteralInt.php
index 1666ca85c..1b0abec1b 100644
--- a/src/Psalm/Type/Atomic/TLiteralInt.php
+++ b/src/Psalm/Type/Atomic/TLiteralInt.php
@@ -29,19 +29,6 @@ class TLiteralInt extends TInt
         return 'int(' . $this->value . ')';
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return $php_major_version >= 7 ? 'int' : null;
-    }
-
     /**
      * @param  array<lowercase-string, string> $aliased_classes
      *
diff --git a/src/Psalm/Type/Atomic/TLiteralString.php b/src/Psalm/Type/Atomic/TLiteralString.php
index e16aa54c4..e59c92e41 100644
--- a/src/Psalm/Type/Atomic/TLiteralString.php
+++ b/src/Psalm/Type/Atomic/TLiteralString.php
@@ -23,11 +23,6 @@ class TLiteralString extends TString
         return 'string(' . $this->value . ')';
     }
 
-    public function __toString(): string
-    {
-        return 'string';
-    }
-
     public function getId(bool $nested = false): string
     {
         // quote control characters, backslashes and double quote
@@ -44,19 +39,6 @@ class TLiteralString extends TString
         return 'string(' . $this->value . ')';
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return $php_major_version >= 7 ? 'string' : null;
-    }
-
     /**
      * @param  array<lowercase-string, string> $aliased_classes
      *
diff --git a/src/Psalm/Type/Atomic/TLowercaseString.php b/src/Psalm/Type/Atomic/TLowercaseString.php
index cb78b5200..b8414be8c 100644
--- a/src/Psalm/Type/Atomic/TLowercaseString.php
+++ b/src/Psalm/Type/Atomic/TLowercaseString.php
@@ -3,11 +3,6 @@ namespace Psalm\Type\Atomic;
 
 class TLowercaseString extends TString
 {
-    public function getKey(bool $include_extra = true): string
-    {
-        return 'string';
-    }
-
     public function getId(bool $nested = false): string
     {
         return 'lowercase-string';
diff --git a/src/Psalm/Type/Atomic/TNamedObject.php b/src/Psalm/Type/Atomic/TNamedObject.php
index feb7de18d..f9bac8935 100644
--- a/src/Psalm/Type/Atomic/TNamedObject.php
+++ b/src/Psalm/Type/Atomic/TNamedObject.php
@@ -144,6 +144,6 @@ class TNamedObject extends Atomic
 
     public function getChildNodes() : array
     {
-        return $this->extra_types !== null ? $this->extra_types : [];
+        return $this->extra_types ?? [];
     }
 }
diff --git a/src/Psalm/Type/Atomic/TNonEmptyLowercaseString.php b/src/Psalm/Type/Atomic/TNonEmptyLowercaseString.php
index d01324013..3ab6ab6bf 100644
--- a/src/Psalm/Type/Atomic/TNonEmptyLowercaseString.php
+++ b/src/Psalm/Type/Atomic/TNonEmptyLowercaseString.php
@@ -6,11 +6,6 @@ namespace Psalm\Type\Atomic;
  */
 class TNonEmptyLowercaseString extends TNonEmptyString
 {
-    public function getKey(bool $include_extra = true): string
-    {
-        return 'string';
-    }
-
     public function getId(bool $nested = false): string
     {
         return 'non-empty-lowercase-string';
diff --git a/src/Psalm/Type/Atomic/TNonEmptyNonspecificLiteralString.php b/src/Psalm/Type/Atomic/TNonEmptyNonspecificLiteralString.php
index 4b6f5657a..9eee2fd1f 100644
--- a/src/Psalm/Type/Atomic/TNonEmptyNonspecificLiteralString.php
+++ b/src/Psalm/Type/Atomic/TNonEmptyNonspecificLiteralString.php
@@ -7,11 +7,6 @@ namespace Psalm\Type\Atomic;
  */
 class TNonEmptyNonspecificLiteralString extends TNonspecificLiteralString
 {
-    public function getKey(bool $include_extra = true): string
-    {
-        return 'string';
-    }
-
     public function getId(bool $nested = false): string
     {
         return 'non-empty-literal-string';
diff --git a/src/Psalm/Type/Atomic/TNonspecificLiteralInt.php b/src/Psalm/Type/Atomic/TNonspecificLiteralInt.php
index 99e20ef04..09481333a 100644
--- a/src/Psalm/Type/Atomic/TNonspecificLiteralInt.php
+++ b/src/Psalm/Type/Atomic/TNonspecificLiteralInt.php
@@ -12,11 +12,6 @@ class TNonspecificLiteralInt extends TInt
         return 'literal-int';
     }
 
-    public function getKey(bool $include_extra = true) : string
-    {
-        return 'int';
-    }
-
     public function canBeFullyExpressedInPhp(int $php_major_version, int $php_minor_version): bool
     {
         return false;
diff --git a/src/Psalm/Type/Atomic/TNonspecificLiteralString.php b/src/Psalm/Type/Atomic/TNonspecificLiteralString.php
index 5a688b596..4d57f6378 100644
--- a/src/Psalm/Type/Atomic/TNonspecificLiteralString.php
+++ b/src/Psalm/Type/Atomic/TNonspecificLiteralString.php
@@ -12,11 +12,6 @@ class TNonspecificLiteralString extends TString
         return 'literal-string';
     }
 
-    public function getKey(bool $include_extra = true) : string
-    {
-        return 'string';
-    }
-
     public function canBeFullyExpressedInPhp(int $php_major_version, int $php_minor_version): bool
     {
         return false;
diff --git a/src/Psalm/Type/Atomic/TTemplateIndexedAccess.php b/src/Psalm/Type/Atomic/TTemplateIndexedAccess.php
index 517e12ff5..4af9887df 100644
--- a/src/Psalm/Type/Atomic/TTemplateIndexedAccess.php
+++ b/src/Psalm/Type/Atomic/TTemplateIndexedAccess.php
@@ -60,17 +60,4 @@ class TTemplateIndexedAccess extends \Psalm\Type\Atomic
     {
         return false;
     }
-
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     *
-     */
-    public function toNamespacedString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        bool $use_phpdoc_format
-    ): string {
-        return $this->getKey();
-    }
 }
diff --git a/src/Psalm/Type/Atomic/TTemplateKeyOf.php b/src/Psalm/Type/Atomic/TTemplateKeyOf.php
index 09958050b..f0982d039 100644
--- a/src/Psalm/Type/Atomic/TTemplateKeyOf.php
+++ b/src/Psalm/Type/Atomic/TTemplateKeyOf.php
@@ -48,27 +48,6 @@ class TTemplateKeyOf extends TArrayKey
         return 'key-of<' . $this->param_name . ':' . $this->defining_class . ' as ' . $this->as->getId() . '>';
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return null;
-    }
-
-    /**
-     * @return false
-     */
-    public function canBeFullyExpressedInPhp(int $php_major_version, int $php_minor_version): bool
-    {
-        return false;
-    }
-
     /**
      * @param array<lowercase-string, string> $aliased_classes
      */
diff --git a/src/Psalm/Type/Atomic/TTemplateParam.php b/src/Psalm/Type/Atomic/TTemplateParam.php
index 1ef9d2eec..b9e5ebc21 100644
--- a/src/Psalm/Type/Atomic/TTemplateParam.php
+++ b/src/Psalm/Type/Atomic/TTemplateParam.php
@@ -100,7 +100,7 @@ class TTemplateParam extends \Psalm\Type\Atomic
                 $namespace,
                 $aliased_classes,
                 $this_class,
-                $use_phpdoc_format
+                true
             );
         }
 
@@ -108,7 +108,7 @@ class TTemplateParam extends \Psalm\Type\Atomic
             $namespace,
             $aliased_classes,
             $this_class,
-            $use_phpdoc_format
+            false
         );
 
         return $this->param_name . $intersection_types;
diff --git a/src/Psalm/Type/Atomic/TTemplateParamClass.php b/src/Psalm/Type/Atomic/TTemplateParamClass.php
index 6dca3507d..9e50cceba 100644
--- a/src/Psalm/Type/Atomic/TTemplateParamClass.php
+++ b/src/Psalm/Type/Atomic/TTemplateParamClass.php
@@ -49,24 +49,6 @@ class TTemplateParamClass extends TClassString
         return 'class-string<' . $this->param_name . '>';
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     */
-    public function toPhpString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        int $php_major_version,
-        int $php_minor_version
-    ): ?string {
-        return 'string';
-    }
-
-    public function canBeFullyExpressedInPhp(int $php_major_version, int $php_minor_version): bool
-    {
-        return false;
-    }
-
     /**
      * @param  array<lowercase-string, string> $aliased_classes
      *
@@ -79,9 +61,4 @@ class TTemplateParamClass extends TClassString
     ): string {
         return $this->param_name . '::class';
     }
-
-    public function getChildNodes() : array
-    {
-        return $this->as_type ? [$this->as_type] : [];
-    }
 }
diff --git a/src/Psalm/Type/Atomic/TTypeAlias.php b/src/Psalm/Type/Atomic/TTypeAlias.php
index 197afd0a1..1003c288c 100644
--- a/src/Psalm/Type/Atomic/TTypeAlias.php
+++ b/src/Psalm/Type/Atomic/TTypeAlias.php
@@ -78,19 +78,6 @@ class TTypeAlias extends \Psalm\Type\Atomic
         return false;
     }
 
-    /**
-     * @param  array<lowercase-string, string> $aliased_classes
-     *
-     */
-    public function toNamespacedString(
-        ?string $namespace,
-        array $aliased_classes,
-        ?string $this_class,
-        bool $use_phpdoc_format
-    ): string {
-        return $this->getKey();
-    }
-
     public function getAssertionString(bool $exact = false): string
     {
         return 'mixed';
diff --git a/src/Psalm/Type/Reconciler.php b/src/Psalm/Type/Reconciler.php
index cfec9f321..0f9334af6 100644
--- a/src/Psalm/Type/Reconciler.php
+++ b/src/Psalm/Type/Reconciler.php
@@ -102,10 +102,8 @@ class Reconciler
 
             foreach ($new_type_parts as $new_type_part_parts) {
                 foreach ($new_type_part_parts as $new_type_part_part) {
-                    switch ($new_type_part_part[0]) {
-                        case '!':
-                            $has_negation = true;
-                            break;
+                    if ($new_type_part_part[0] === '!') {
+                        $has_negation = true;
                     }
 
                     $has_isset = $has_isset
diff --git a/src/Psalm/Type/Union.php b/src/Psalm/Type/Union.php
index 00c0ca9e4..1f19e8f0b 100644
--- a/src/Psalm/Type/Union.php
+++ b/src/Psalm/Type/Union.php
@@ -26,7 +26,6 @@ use function implode;
 use function reset;
 use function sort;
 use function strpos;
-use function strval;
 
 class Union implements TypeNode
 {
@@ -80,7 +79,7 @@ class Union implements TypeNode
      *
      * @var ?string
      */
-    public $initialized_class = null;
+    public $initialized_class;
 
     /**
      * Whether or not the type has been checked yet
@@ -336,7 +335,7 @@ class Union implements TypeNode
                 $printed_int = true;
             }
 
-            $types[] = strval($type);
+            $types[] = (string)$type;
         }
 
         sort($types);
@@ -374,7 +373,7 @@ class Union implements TypeNode
                 $types[] = 'int';
                 $printed_int = true;
             } else {
-                $types[] = strval($type->getKey());
+                $types[] = $type->getKey();
             }
         }
 
@@ -390,7 +389,7 @@ class Union implements TypeNode
 
         $types = [];
         foreach ($this->types as $type) {
-            $types[] = strval($type->getId());
+            $types[] = $type->getId();
         }
         sort($types);
 
@@ -637,7 +636,7 @@ class Union implements TypeNode
 
     public function hasArrayAccessInterface(Codebase $codebase) : bool
     {
-        return !!array_filter(
+        return (bool)array_filter(
             $this->types,
             function ($type) use ($codebase) {
                 return $type->hasArrayAccessInterface($codebase);