Introduce BeforeExpressionAnalysisEvent

src/Psalm/Internal/Analyzer/Statements/ExpressionAnalyzer.php

@@ -53,6 +53,7 @@ use Psalm\Issue\UnrecognizedExpression;
 use Psalm\Issue\UnsupportedReferenceUsage;
 use Psalm\IssueBuffer;
 use Psalm\Plugin\EventHandler\Event\AfterExpressionAnalysisEvent;
+use Psalm\Plugin\EventHandler\Event\BeforeExpressionAnalysisEvent;
 use Psalm\Storage\FunctionLikeParameter;
 use Psalm\Type;
 use Psalm\Type\TaintKind;
@@ -80,6 +81,10 @@ class ExpressionAnalyzer
         ?TemplateResult $template_result = null,
         bool $assigned_to_reference = false
     ): bool {
+        if (self::dispatchBeforeExpressionAnalysis($stmt, $context, $statements_analyzer) === false) {
+            return false;
+        }
+
         $codebase = $statements_analyzer->getCodebase();
 
         if (self::handleExpression(
@@ -126,24 +131,10 @@ class ExpressionAnalyzer
             }
         }
 
-        $event = new AfterExpressionAnalysisEvent(
-            $stmt,
-            $context,
-            $statements_analyzer,
-            $codebase,
-            [],
-        );
-
-        if ($codebase->config->eventDispatcher->dispatchAfterExpressionAnalysis($event) === false) {
+        if (self::dispatchAfterExpressionAnalysis($stmt, $context, $statements_analyzer) === false) {
             return false;
         }
 
-        $file_manipulations = $event->getFileReplacements();
-
-        if ($file_manipulations) {
-            FileManipulationBuffer::add($statements_analyzer->getFilePath(), $file_manipulations);
-        }
-
         return true;
     }
 
@@ -554,4 +545,60 @@ class ExpressionAnalyzer
 
         return true;
     }
+
+    private static function dispatchBeforeExpressionAnalysis(
+        PhpParser\Node\Expr $expr,
+        Context $context,
+        StatementsAnalyzer $statements_analyzer
+    ): ?bool {
+        $codebase = $statements_analyzer->getCodebase();
+
+        $event = new BeforeExpressionAnalysisEvent(
+            $expr,
+            $context,
+            $statements_analyzer,
+            $codebase,
+            [],
+        );
+
+        if ($codebase->config->eventDispatcher->dispatchBeforeExpressionAnalysis($event) === false) {
+            return false;
+        }
+
+        $file_manipulations = $event->getFileReplacements();
+
+        if (!empty($file_manipulations)) {
+            FileManipulationBuffer::add($statements_analyzer->getFilePath(), $file_manipulations);
+        }
+
+        return null;
+    }
+
+    private static function dispatchAfterExpressionAnalysis(
+        PhpParser\Node\Expr $expr,
+        Context $context,
+        StatementsAnalyzer $statements_analyzer
+    ): ?bool {
+        $codebase = $statements_analyzer->getCodebase();
+
+        $event = new AfterExpressionAnalysisEvent(
+            $expr,
+            $context,
+            $statements_analyzer,
+            $codebase,
+            [],
+        );
+
+        if ($codebase->config->eventDispatcher->dispatchAfterExpressionAnalysis($event) === false) {
+            return false;
+        }
+
+        $file_manipulations = $event->getFileReplacements();
+
+        if (!empty($file_manipulations)) {
+            FileManipulationBuffer::add($statements_analyzer->getFilePath(), $file_manipulations);
+        }
+
+        return null;
+    }
 }

src/Psalm/Internal/EventDispatcher.php

@@ -16,6 +16,7 @@ use Psalm\Plugin\EventHandler\AfterFunctionLikeAnalysisInterface;
 use Psalm\Plugin\EventHandler\AfterMethodCallAnalysisInterface;
 use Psalm\Plugin\EventHandler\AfterStatementAnalysisInterface;
 use Psalm\Plugin\EventHandler\BeforeAddIssueInterface;
+use Psalm\Plugin\EventHandler\BeforeExpressionAnalysisInterface;
 use Psalm\Plugin\EventHandler\BeforeFileAnalysisInterface;
 use Psalm\Plugin\EventHandler\BeforeStatementAnalysisInterface;
 use Psalm\Plugin\EventHandler\Event\AddRemoveTaintsEvent;
@@ -32,6 +33,7 @@ use Psalm\Plugin\EventHandler\Event\AfterFunctionLikeAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\AfterMethodCallAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\AfterStatementAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\BeforeAddIssueEvent;
+use Psalm\Plugin\EventHandler\Event\BeforeExpressionAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\BeforeFileAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\BeforeStatementAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\StringInterpreterEvent;
@@ -77,6 +79,13 @@ class EventDispatcher
      */
     public array $after_every_function_checks = [];
 
+    /**
+     * Static methods to be called before expression checks are completed
+     *
+     * @var list<class-string<BeforeExpressionAnalysisInterface>>
+     */
+    public array $before_expression_checks = [];
+
     /**
      * Static methods to be called after expression checks have completed
      *
@@ -197,6 +206,10 @@ class EventDispatcher
             $this->after_every_function_checks[] = $class;
         }
 
+        if (is_subclass_of($class, BeforeExpressionAnalysisInterface::class)) {
+            $this->before_expression_checks[] = $class;
+        }
+
         if (is_subclass_of($class, AfterExpressionAnalysisInterface::class)) {
             $this->after_expression_checks[] = $class;
         }
@@ -284,6 +297,17 @@ class EventDispatcher
         }
     }
 
+    public function dispatchBeforeExpressionAnalysis(BeforeExpressionAnalysisEvent $event): ?bool
+    {
+        foreach ($this->before_expression_checks as $handler) {
+            if ($handler::beforeExpressionAnalysis($event) === false) {
+                return false;
+            }
+        }
+
+        return null;
+    }
+
     public function dispatchAfterExpressionAnalysis(AfterExpressionAnalysisEvent $event): ?bool
     {
         foreach ($this->after_expression_checks as $handler) {

src/Psalm/Plugin/EventHandler/BeforeExpressionAnalysisInterface.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Psalm\Plugin\EventHandler;
+
+use Psalm\Plugin\EventHandler\Event\BeforeExpressionAnalysisEvent;
+
+interface BeforeExpressionAnalysisInterface
+{
+    /**
+     * Called before an expression is checked
+     */
+    public static function beforeExpressionAnalysis(BeforeExpressionAnalysisEvent $event): ?bool;
+}

src/Psalm/Plugin/EventHandler/Event/BeforeExpressionAnalysisEvent.php

@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Psalm\Plugin\EventHandler\Event;
+
+use PhpParser\Node\Expr;
+use Psalm\Codebase;
+use Psalm\Context;
+use Psalm\FileManipulation;
+use Psalm\StatementsSource;
+
+final class BeforeExpressionAnalysisEvent
+{
+    private Expr $expr;
+    private Context $context;
+    private StatementsSource $statements_source;
+    private Codebase $codebase;
+    /**
+     * @var list<FileManipulation>
+     */
+    private array $file_replacements;
+
+    /**
+     * Called before an expression is checked
+     *
+     * @param  list<FileManipulation> $file_replacements
+     * @internal
+     */
+    public function __construct(
+        Expr $expr,
+        Context $context,
+        StatementsSource $statements_source,
+        Codebase $codebase,
+        array $file_replacements = []
+    ) {
+        $this->expr = $expr;
+        $this->context = $context;
+        $this->statements_source = $statements_source;
+        $this->codebase = $codebase;
+        $this->file_replacements = $file_replacements;
+    }
+
+    public function getExpr(): Expr
+    {
+        return $this->expr;
+    }
+
+    public function getContext(): Context
+    {
+        return $this->context;
+    }
+
+    public function getStatementsSource(): StatementsSource
+    {
+        return $this->statements_source;
+    }
+
+    public function getCodebase(): Codebase
+    {
+        return $this->codebase;
+    }
+
+    /**
+     * @return list<FileManipulation>
+     */
+    public function getFileReplacements(): array
+    {
+        return $this->file_replacements;
+    }
+
+    /**
+     * @param list<FileManipulation> $file_replacements
+     */
+    public function setFileReplacements(array $file_replacements): void
+    {
+        $this->file_replacements = $file_replacements;
+    }
+}