Merge pull request #922 from WinterSilence/patch-1

Add `ReflectionFunctionAbstract::couldThrow()`

src/Reflection/ReflectionFunctionAbstract.php

@@ -8,7 +8,9 @@
 use PhpParser\Node;
 use PhpParser\Node\Expr\Yield_ as YieldNode;
 use PhpParser\Node\Expr\YieldFrom as YieldFromNode;
+use PhpParser\Node\Stmt\Throw_ as NodeThrow;
 use PhpParser\NodeTraverser;
+use PhpParser\NodeVisitor\FindingVisitor;
 use PhpParser\PrettyPrinter\Standard as StandardPrettyPrinter;
 use PhpParser\PrettyPrinterAbstract;
 use Roave\BetterReflection\Reflection\Annotation\AnnotationHelper;
@@ -188,6 +190,17 @@ public function isVariadic(): bool
         return false;
     }
 
+    /** Checks if the function/method contains `throw` expressions. */
+    public function couldThrow(): bool
+    {
+        $visitor   = new FindingVisitor(static fn (Node $node): bool => $node instanceof NodeThrow);
+        $traverser = new NodeTraverser();
+        $traverser->addVisitor($visitor);
+        $traverser->traverse($this->getBodyAst());
+
+        return $visitor->getFoundNodes() !== [];
+    }
+
     /**
      * Recursively search an array of statements (PhpParser nodes) to find if a
      * yield expression exists anywhere (thus indicating this is a generator).

test/unit/Reflection/ReflectionFunctionAbstractTest.php

@@ -700,4 +700,29 @@ public function testGetAttributesByInstance(): void
 
         self::assertCount(2, $attributes);
     }
+
+    public function testCouldThrow(): void
+    {
+        $php       = <<<'PHP'
+        <?php
+        function foo($a) {
+            if ($a === null) {
+                throw new Exception('Invalid a!');
+            }
+        }
+        PHP;
+        $reflector = new DefaultReflector(new StringSourceLocator($php, $this->astLocator));
+        $function  = $reflector->reflectFunction('foo');
+        self::assertTrue($function->couldThrow());
+
+        $php       = <<<'PHP'
+        <?php
+        function foo(object $obj) {
+            echo $obj instanceof Throwable ? 'throw' : 'not throw';
+        }
+        PHP;
+        $reflector = new DefaultReflector(new StringSourceLocator($php, $this->astLocator));
+        $function  = $reflector->reflectFunction('foo');
+        self::assertNotTrue($function->couldThrow());
+    }
 }