Bleeding edge - Precise array shape for preg_match_callback() $matches

Author: staabm

conf/config.neon

@@ -295,6 +295,8 @@ conditionalTags:
 		phpstan.typeSpecifier.functionTypeSpecifyingExtension: %featureToggles.narrowPregMatches%
 	PHPStan\Type\Php\PregMatchParameterOutTypeExtension:
 		phpstan.functionParameterOutTypeExtension: %featureToggles.narrowPregMatches%
+	PHPStan\Type\Php\PregMatchCallbackClosureTypeExtension:
+		phpstan.functionParameterClosureTypeExtension: %featureToggles.narrowPregMatches%
 
 services:
 	-
@@ -1497,6 +1499,9 @@ services:
 	-
 		class: PHPStan\Type\Php\PregMatchParameterOutTypeExtension
 
+	-
+		class: PHPStan\Type\Php\PregMatchCallbackClosureTypeExtension
+
 	-
 		class: PHPStan\Type\Php\RegexArrayShapeMatcher
 

src/Type/Php/PregMatchCallbackClosureTypeExtension.php

@@ -0,0 +1,60 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PhpParser\Node\Expr\FuncCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Reflection\Native\NativeParameterReflection;
+use PHPStan\Reflection\ParameterReflection;
+use PHPStan\TrinaryLogic;
+use PHPStan\Type\ClosureType;
+use PHPStan\Type\FunctionParameterClosureTypeExtension;
+use PHPStan\Type\StringType;
+use PHPStan\Type\Type;
+
+final class PregMatchCallbackClosureTypeExtension implements FunctionParameterClosureTypeExtension
+{
+
+	public function __construct(
+		private RegexArrayShapeMatcher $regexShapeMatcher,
+	)
+	{
+	}
+
+	public function isFunctionSupported(FunctionReflection $functionReflection, ParameterReflection $parameter): bool
+	{
+		return $functionReflection->getName() === 'preg_replace_callback' && $parameter->getName() === 'callback';
+	}
+
+	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, ParameterReflection $parameter, Scope $scope): ?Type
+	{
+		$args = $functionCall->getArgs();
+		$patternArg = $args[0] ?? null;
+		$flagsArg = $args[5] ?? null;
+
+		if (
+			$patternArg === null
+		) {
+			return null;
+		}
+
+		$flagsType = null;
+		if ($flagsArg !== null) {
+			$flagsType = $scope->getType($flagsArg->value);
+		}
+
+		$matchesType = $this->regexShapeMatcher->matchExpr($patternArg->value, $flagsType, TrinaryLogic::createYes(), $scope);
+		if ($matchesType === null) {
+			return null;
+		}
+
+		return new ClosureType(
+			[
+				new NativeParameterReflection($parameter->getName(), $parameter->isOptional(), $matchesType, $parameter->passedByReference(), $parameter->isVariadic(), $parameter->getDefaultValue()),
+			],
+			new StringType(),
+		);
+	}
+
+}

tests/PHPStan/Analyser/nsrt/preg_replace_callback_shapes.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace PregReplaceCallbackMatchShapes;
+
+use function PHPStan\Testing\assertType;
+
+function (string $s): void {
+	preg_replace_callback(
+		'|<p>(\s*)\w|',
+		function ($matches) {
+			assertType('array{string, string}', $matches);
+			return '';
+		},
+		$s
+	);
+};
+
+function (string $s): void {
+	preg_replace_callback(
+		'/(foo)?(bar)?(baz)?/',
+		function ($matches) {
+			assertType('array{string, non-empty-string|null, non-empty-string|null, non-empty-string|null}', $matches);
+			return '';
+		},
+		$s,
+		-1,
+		$count,
+		PREG_UNMATCHED_AS_NULL
+	);
+};
+
+function (string $s): void {
+	preg_replace_callback(
+		'/(foo)?(bar)?(baz)?/',
+		function ($matches) {
+			assertType('array{0: array{string, int<0, max>}, 1?: array{non-empty-string, int<0, max>}, 2?: array{non-empty-string, int<0, max>}, 3?: array{non-empty-string, int<0, max>}}', $matches);
+			return '';
+		},
+		$s,
+		-1,
+		$count,
+		PREG_OFFSET_CAPTURE
+	);
+};
+
+function (string $s): void {
+	preg_replace_callback(
+		'/(foo)?(bar)?(baz)?/',
+		function ($matches) {
+			assertType('array{array{string|null, int<-1, max>}, array{non-empty-string|null, int<-1, max>}, array{non-empty-string|null, int<-1, max>}, array{non-empty-string|null, int<-1, max>}}', $matches);
+			return '';
+		},
+		$s,
+		-1,
+		$count,
+		PREG_OFFSET_CAPTURE|PREG_UNMATCHED_AS_NULL
+	);
+};