From 2fc2cba098e58821bc38c63cc216e4deee2eef00 Mon Sep 17 00:00:00 2001
From: Jean-Luc Herren <jlh@gmx.ch>
Date: Wed, 30 Jun 2021 21:33:04 +0200
Subject: [PATCH] Add return type extension for strval()

---
 conf/config.neon                              |  5 +++
 .../Php/StrvalFunctionReturnTypeExtension.php | 33 +++++++++++++++++++
 .../Analyser/NodeScopeResolverTest.php        |  1 +
 tests/PHPStan/Analyser/data/strval.php        | 19 +++++++++++
 4 files changed, 58 insertions(+)
 create mode 100644 src/Type/Php/StrvalFunctionReturnTypeExtension.php
 create mode 100644 tests/PHPStan/Analyser/data/strval.php

diff --git a/conf/config.neon b/conf/config.neon
index aa13516293..6ae19bb2db 100644
--- a/conf/config.neon
+++ b/conf/config.neon
@@ -1397,6 +1397,11 @@ services:
 		tags:
 			- phpstan.broker.dynamicFunctionReturnTypeExtension
 
+	-
+		class: PHPStan\Type\Php\StrvalFunctionReturnTypeExtension
+		tags:
+			- phpstan.broker.dynamicFunctionReturnTypeExtension
+
 	-
 		class: PHPStan\Type\Php\StrWordCountFunctionDynamicReturnTypeExtension
 		tags:
diff --git a/src/Type/Php/StrvalFunctionReturnTypeExtension.php b/src/Type/Php/StrvalFunctionReturnTypeExtension.php
new file mode 100644
index 0000000000..391003efcb
--- /dev/null
+++ b/src/Type/Php/StrvalFunctionReturnTypeExtension.php
@@ -0,0 +1,33 @@
+<?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\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\NullType;
+use PHPStan\Type\Type;
+
+class StrvalFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
+{
+
+	public function isFunctionSupported(FunctionReflection $functionReflection): bool
+	{
+		return $functionReflection->getName() === 'strval';
+	}
+
+	public function getTypeFromFunctionCall(
+		FunctionReflection $functionReflection,
+		FuncCall $functionCall,
+		Scope $scope
+	): Type
+	{
+		if (count($functionCall->args) === 0) {
+			return new NullType();
+		}
+		$argType = $scope->getType($functionCall->args[0]->value);
+		return $argType->toString();
+	}
+
+}
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
index 19a7405266..5bfb578ccf 100644
--- a/tests/PHPStan/Analyser/NodeScopeResolverTest.php
+++ b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -430,6 +430,7 @@ public function dataFileAsserts(): iterable
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/closure-types.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-5219.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/strval.php');
 	}
 
 	/**
diff --git a/tests/PHPStan/Analyser/data/strval.php b/tests/PHPStan/Analyser/data/strval.php
new file mode 100644
index 0000000000..04689cbcb8
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/strval.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace StrvalTest;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param class-string<\stdClass> $class
+ */
+function test(string $class)
+{
+	assertType('\'foo\'', strval('foo'));
+	assertType('\'\'', strval(null));
+	assertType('\'\'|\'1\'', strval(rand(0, 1) === 0));
+	assertType('string&numeric', strval(rand()));
+	assertType('string&numeric', strval(rand() * 0.1));
+	assertType('string&numeric', strval(strval(rand())));
+	assertType('class-string<stdClass>', strval($class));
+}