Fix #838 - check assertions, even outside conditionals

src/Psalm/Checker/ClassChecker.php

@@ -418,9 +418,7 @@ class ClassChecker extends ClassLikeChecker
                     }
                 }
             } elseif ($stmt instanceof PhpParser\Node\Stmt\ClassConst) {
-                foreach ($stmt->consts as $consts) {
-                    $member_stmts[] = $stmt;
-                }
+                $member_stmts[] = $stmt;
             }
         }
 

src/Psalm/Checker/FunctionChecker.php

@@ -765,7 +765,9 @@ class FunctionChecker extends FunctionLikeChecker
                         && $stmt instanceof PhpParser\Node\Stmt\Return_
                         && $stmt->expr
                     ) {
-                        $assertions = AssertionFinder::getAssertions($stmt->expr, null, $statements_checker);
+                        AssertionFinder::scrapeAssertions($stmt->expr, null, $statements_checker);
+
+                        $assertions = isset($stmt->expr->assertions) ? $stmt->expr->assertions : null;
 
                         if (isset($assertions['$' . $first_param->var->name])) {
                             $changed_var_ids = [];

src/Psalm/Checker/Statements/ExpressionChecker.php

@@ -8,6 +8,7 @@ use Psalm\Checker\CommentChecker;
 use Psalm\Checker\FunctionLikeChecker;
 use Psalm\Checker\ProjectChecker;
 use Psalm\Checker\Statements\Expression\ArrayChecker;
+use Psalm\Checker\Statements\Expression\AssertionFinder;
 use Psalm\Checker\Statements\Expression\AssignmentChecker;
 use Psalm\Checker\Statements\Expression\BinaryOpChecker;
 use Psalm\Checker\Statements\Expression\Call\FunctionCallChecker;
@@ -532,6 +533,22 @@ class ExpressionChecker
             }
         }
 
+        if (!$context->inside_conditional
+            && ($stmt instanceof PhpParser\Node\Expr\BinaryOp
+                || $stmt instanceof PhpParser\Node\Expr\Instanceof_
+                || $stmt instanceof PhpParser\Node\Expr\Assign
+                || $stmt instanceof PhpParser\Node\Expr\BooleanNot
+                || $stmt instanceof PhpParser\Node\Expr\Empty_
+                || $stmt instanceof PhpParser\Node\Expr\Isset_
+                || $stmt instanceof PhpParser\Node\Expr\FuncCall)
+        ) {
+            AssertionFinder::scrapeAssertions(
+                $stmt,
+                $context->self,
+                $statements_checker
+            );
+        }
+
         $project_checker = $statements_checker->getFileChecker()->project_checker;
 
         $plugin_classes = $project_checker->config->after_expression_checks;

src/Psalm/PropertyMap.php

@@ -396,6 +396,7 @@ return [
     ],
     'phpparser\\node\\expr' => [
         'inferredType' => 'Psalm\\Type\\Union|null',
+        'assertions' => 'array<string, array<int, array<int, string>>>|null',
     ],
     'phpparser\\node\\name' => [
         'inferredType' => 'Psalm\\Type\\Union|null',

src/Psalm/Type/Algebra.php

@@ -118,13 +118,15 @@ class Algebra
             return self::combineOredClauses($left_clauses, $right_clauses);
         }
 
-        $assertions = AssertionFinder::getAssertions(
+        AssertionFinder::scrapeAssertions(
             $conditional,
             $this_class_name,
             $source
         );
 
-        if ($assertions) {
+        if (isset($conditional->assertions) && $conditional->assertions) {
+            $assertions = $conditional->assertions;
+
             $clauses = [];
 
             foreach ($assertions as $var => $anded_types) {

tests/RedundantConditionTest.php

@@ -730,6 +730,30 @@ class RedundantConditionTest extends TestCase
                     }',
                 'error_message' => 'RedundantCondition',
             ],
+            'impossibleNullEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i !== null;',
+                'error_message' => 'RedundantCondition',
+            ],
+            'impossibleTrueEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i !== true;',
+                'error_message' => 'RedundantCondition',
+            ],
+            'impossibleFalseEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i !== false;',
+                'error_message' => 'RedundantCondition',
+            ],
+            'impossibleNumberEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i !== 3;',
+                'error_message' => 'RedundantCondition',
+            ],
         ];
     }
 }

tests/TypeReconciliationTest.php

@@ -1070,6 +1070,30 @@ class TypeReconciliationTest extends TestCase
                     }',
                 'error_message' => 'TypeDoesNotContainType',
             ],
+            'impossibleNullEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i === null;',
+                'error_message' => 'TypeDoesNotContainNull',
+            ],
+            'impossibleTrueEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i === true;',
+                'error_message' => 'TypeDoesNotContainType',
+            ],
+            'impossibleFalseEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i === false;',
+                'error_message' => 'TypeDoesNotContainType',
+            ],
+            'impossibleNumberEquality' => [
+                '<?php
+                    $i = 5;
+                    echo $i === 3;',
+                'error_message' => 'TypeDoesNotContainType',
+            ],
         ];
     }
 }