get_defined_vars() return type contains known variables

Co-Authored-By: Ruud Kamphuis <ruudk@users.noreply.github.com>

Author: 2 people

conf/config.neon

@@ -1525,6 +1525,11 @@ 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 +1,46 @@
+<?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\ConstantArrayTypeBuilder;
+use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\StringType;
+use PHPStan\Type\Type;
+
+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(),
+			);
+		}
+
+		$typeBuilder = ConstantArrayTypeBuilder::createEmpty();
+
+		foreach ($scope->getDefinedVariables() as $variable) {
+			$typeBuilder->setOffsetValueType(new ConstantStringType($variable), $scope->getVariableType($variable), false);
+		}
+
+		foreach ($scope->getMaybeDefinedVariables() as $variable) {
+			$typeBuilder->setOffsetValueType(new ConstantStringType($variable), $scope->getVariableType($variable), true);
+		}
+
+		return $typeBuilder->getArray();
+	}
+
+}

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

@@ -0,0 +1,46 @@
+<?php
+
+namespace GetDefinedVars;
+
+use function PHPStan\Testing\assertType;
+
+$global = "foo";
+
+assertType('array<string, mixed>', get_defined_vars()); // any variable can exist
+
+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) {
+	global $global;
+	$local = "foo";
+	assertType('array{param: int, global: mixed, local: \'foo\'}', get_defined_vars());
+	assertType('array{\'param\', \'global\', \'local\'}', array_keys(get_defined_vars()));
+}
+
+function doConditional(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 doRandom(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());
+}