From a503e9b6e2ca12f1360fb66191ad0d7426ca5a18 Mon Sep 17 00:00:00 2001
From: Martin Jonas <martin.jonas@growjob.com>
Date: Mon, 11 Nov 2024 17:15:04 +0100
Subject: [PATCH] get_defined_vars() return type contains known variables

Co-Authored-By: Ruud Kamphuis <ruudk@users.noreply.github.com>
---
 conf/config.neon                              |  5 ++
 ...DefinedVarsFunctionReturnTypeExtension.php | 46 +++++++++++++++++++
 .../Analyser/nsrt/get-defined-vars.php        | 46 +++++++++++++++++++
 3 files changed, 97 insertions(+)
 create mode 100644 src/Type/Php/GetDefinedVarsFunctionReturnTypeExtension.php
 create mode 100644 tests/PHPStan/Analyser/nsrt/get-defined-vars.php

diff --git a/conf/config.neon b/conf/config.neon
index f8ad1af8b3..19b6388858 100644
--- a/conf/config.neon
+++ b/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:
diff --git a/src/Type/Php/GetDefinedVarsFunctionReturnTypeExtension.php b/src/Type/Php/GetDefinedVarsFunctionReturnTypeExtension.php
new file mode 100644
index 0000000000..35999b424b
--- /dev/null
+++ b/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 $typeBuilder->getArray();
+	}
+
+}
diff --git a/tests/PHPStan/Analyser/nsrt/get-defined-vars.php b/tests/PHPStan/Analyser/nsrt/get-defined-vars.php
new file mode 100644
index 0000000000..345d54dbd3
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/get-defined-vars.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace GetDefinedVars;
+
+use function PHPStan\Testing\assertType;
+
+$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());
+}