get_defined_vars() return type contains know variables

Author: MartinMystikJonas

conf/config.neon

@@ -1427,6 +1427,11 @@ services:
 tags:
 - phpstan.broker.dynamicFunctionReturnTypeExtension
 
+-
+class: PHPStan\Type\Php\GetDefinedVarsFunctionReturnTypeExtension
+tags:
+- phpstan.broker.dynamicFunctionReturnTypeExtension
+
 -
 class: PHPStan\Type\Php\GetParentClassDynamicFunctionReturnTypeExtension
 tags:

src/Type/Php/GetDefinedVarsFunctionReturnTypeExtension.php

@@ -0,0 +1,68 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PhpParser\Node\Expr\FuncCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\Constant\ConstantArrayType;
+use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\StringType;
+use PHPStan\Type\Type;
+use function array_filter;
+use function array_map;
+use function array_merge;
+use function array_values;
+use function count;
+use function range;
+
+// based on code by @ruudk
+final class GetDefinedVarsFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
+{
+
+public function isFunctionSupported(FunctionReflection $functionReflection): bool
+{
+return $functionReflection->getName() === 'get_defined_vars';
+}
+
+public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): Type
+{
+if ($scope->canAnyVariableExist()) {
+return new ArrayType(
+new StringType(),
+new MixedType(),
+);
+}
+
+$variables = array_values(array_filter(
+$scope->getDefinedVariables(),
+static fn ($variable) => $variable !== 'this',
+));
+
+$maybeVariables = array_values(
+$scope->getMaybeDefinedVariables(),
+);
+
+$keys = array_map(
+static fn ($variable) => new ConstantStringType($variable),
+array_merge($variables, $maybeVariables),
+);
+
+$values = array_map(
+static fn ($variable) => $scope->getVariableType($variable),
+array_merge($variables, $maybeVariables),
+);
+
+if ($maybeVariables !== []) {
+$maybeIndexes = range(count($variables), count($variables) + count($maybeVariables));
+} else {
+$maybeIndexes = [];
+}
+
+return new ConstantArrayType($keys, $values, [0], $maybeIndexes);
+}
+
+}

tests/PHPStan/Analyser/nsrt/get-defined-vars.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace GetDefinedVars;
+
+use function PHPStan\Testing\assertType;
+
+function doFoo(int $param) {
+$local = "foo";
+assertType('array{param: int, local: \'foo\'}', get_defined_vars());
+assertType('array{\'param\', \'local\'}', array_keys(get_defined_vars()));
+}
+
+function doBar(int $param) {
+$local = "foo";
+if(true) {
+$conditional = "bar";
+assertType('array{param: int, local: \'foo\', conditional: \'bar\'}', get_defined_vars());
+} else {
+$other = "baz";
+assertType('array{param: int, local: \'foo\', other: \'baz\'}', get_defined_vars());
+}
+assertType('array{param: int, local: \'foo\', conditional: \'bar\'}', get_defined_vars());
+}
+
+function doBaz(int $param) {
+$local = "foo";
+if(rand(0, 1)) {
+$random1 = "bar";
+assertType('array{param: int, local: \'foo\', random1: \'bar\'}', get_defined_vars());
+} else {
+$random2 = "baz";
+assertType('array{param: int, local: \'foo\', random2: \'baz\'}', get_defined_vars());
+}
+assertType('array{param: int, local: \'foo\', random2?: \'baz\', random1?: \'bar\'}', get_defined_vars());
+}