array_key_exists - fix for AST-based offset

ondrejmirtes · ondrejmirtes · commit 8613169c105f · 2022-08-09T22:26:57.000+02:00
diff --git a/src/Type/Php/ArrayKeyExistsFunctionTypeSpecifyingExtension.php b/src/Type/Php/ArrayKeyExistsFunctionTypeSpecifyingExtension.php
@@ -2,7 +2,11 @@
 
 namespace PHPStan\Type\Php;
 
+use PhpParser\Node\Expr\ArrayDimFetch;
+use PhpParser\Node\Expr\BinaryOp\Identical;
+use PhpParser\Node\Expr\ConstFetch;
 use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Name;
 use PHPStan\Analyser\Scope;
 use PHPStan\Analyser\SpecifiedTypes;
 use PHPStan\Analyser\TypeSpecifier;
@@ -48,8 +52,18 @@ public function specifyTypes(
 		if (count($node->getArgs()) < 2) {
 			return new SpecifiedTypes();
 		}
-		$keyType = $scope->getType($node->getArgs()[0]->value);
+		$key = $node->getArgs()[0]->value;
+		$array = $node->getArgs()[1]->value;
+		$keyType = $scope->getType($key);
 		if (!$keyType instanceof ConstantIntegerType && !$keyType instanceof ConstantStringType) {
+			if ($context->truthy()) {
+				$arrayDimFetch = new ArrayDimFetch(
+					$array,
+					$key,
+				);
+				return $this->typeSpecifier->create($arrayDimFetch, $scope->getType($array)->getIterableValueType(), $context, false, $scope, new Identical($arrayDimFetch, new ConstFetch(new Name('__PHPSTAN_FAUX_CONSTANT'))));
+			}
+
 			return new SpecifiedTypes();
 		}
 
@@ -63,7 +77,7 @@ public function specifyTypes(
 		}
 
 		return $this->typeSpecifier->create(
-			$node->getArgs()[1]->value,
+			$array,
 			$type,
 			$context,
 			false,
diff --git a/tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php b/tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php
@@ -499,4 +499,13 @@ public function testBug7469(): void
 		$this->analyse([__DIR__ . '/data/bug-7469.php'], $expected);
 	}
 
+	public function testBug7763(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1.');
+		}
+
+		$this->analyse([__DIR__ . '/data/bug-7763.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Arrays/data/bug-7763.php b/tests/PHPStan/Rules/Arrays/data/bug-7763.php
@@ -0,0 +1,27 @@
+<?php // lint >= 8.1
+
+namespace Bug7763;
+
+enum MyEnum: int {
+	case Case1 = 1;
+	case Case2 = 2;
+
+	public function test(self $enum): string
+	{
+		$mapping = array_filter([
+			self::Case1->value => $this->maybeNull(),
+			self::Case2->value => $this->maybeNull(),
+		]);
+
+		if (array_key_exists($enum->value, $mapping)) {
+			return $mapping[$enum->value]; // Offset 1|2 does not exist on array{1?: non-falsy-string, 2?: non-falsy-string}
+		}
+
+		return '';
+	}
+
+	private function maybeNull(): ?string
+	{
+		return (bool) rand(0, 1) ? '' : null;
+	}
+}

Original file line number	Diff line number	Diff line change
`@@ -499,4 +499,13 @@ public function testBug7469(): void`
`499`	`499`	`$this->analyse([__DIR__ . '/data/bug-7469.php'], $expected);`
`500`	`500`	`}`
`501`	`501`
	`502`	`+ public function testBug7763(): void`
	`503`	`+ {`
	`504`	`+ if (PHP_VERSION_ID < 80100) {`
	`505`	`+ $this->markTestSkipped('Test requires PHP 8.1.');`
	`506`	`+ }`
	`507`	`+`
	`508`	`+ $this->analyse([__DIR__ . '/data/bug-7763.php'], []);`
	`509`	`+ }`
	`510`	`+`
`502`	`511`	`}`