ExpressionTypeResolverExtension for yield in PHPStan\Analyser\Generator namespace

Author: ondrejmirtes

build/PHPStan/Build/GeneratorYieldSendTypeExtension.php

@@ -0,0 +1,58 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Build;
+
+use PhpParser\Node\Expr;
+use PHPStan\Analyser\Generator\ExprAnalysisRequest;
+use PHPStan\Analyser\Generator\ExprAnalysisResult;
+use PHPStan\Analyser\Generator\NodeCallbackRequest;
+use PHPStan\Analyser\Generator\StmtAnalysisRequest;
+use PHPStan\Analyser\Generator\StmtAnalysisResult;
+use PHPStan\Analyser\Generator\StmtsAnalysisRequest;
+use PHPStan\Analyser\Scope;
+use PHPStan\Type\ExpressionTypeResolverExtension;
+use PHPStan\Type\NullType;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\Type;
+use function str_starts_with;
+
+final class GeneratorYieldSendTypeExtension implements ExpressionTypeResolverExtension
+{
+
+	public function getType(Expr $expr, Scope $scope): ?Type
+	{
+		if (!$expr instanceof Expr\Yield_) {
+			return null;
+		}
+
+		if ($expr->value === null) {
+			return null;
+		}
+
+		$namespace = $scope->getNamespace();
+		if ($namespace === null) {
+			return null;
+		}
+
+		if (!str_starts_with($namespace . '\\', 'PHPStan\\Analyser\\Generator\\')) {
+			return null;
+		}
+
+		$valueType = $scope->getType($expr->value);
+		if ((new ObjectType(ExprAnalysisRequest::class))->isSuperTypeOf($valueType)->yes()) {
+			return new ObjectType(ExprAnalysisResult::class);
+		}
+		if ((new ObjectType(StmtAnalysisRequest::class))->isSuperTypeOf($valueType)->yes()) {
+			return new ObjectType(StmtAnalysisResult::class);
+		}
+		if ((new ObjectType(StmtsAnalysisRequest::class))->isSuperTypeOf($valueType)->yes()) {
+			return new ObjectType(StmtAnalysisResult::class);
+		}
+		if ((new ObjectType(NodeCallbackRequest::class))->isSuperTypeOf($valueType)->yes()) {
+			return new NullType();
+		}
+
+		return null;
+	}
+
+}

build/phpstan.neon

@@ -147,3 +147,7 @@ services:
 		class: PHPStan\Build\ContainerDynamicReturnTypeExtension
 		tags:
 			- phpstan.broker.dynamicMethodReturnTypeExtension
+	-
+		class: PHPStan\Build\GeneratorYieldSendTypeExtension
+		tags:
+			- phpstan.broker.expressionTypeResolverExtension

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -302,6 +302,7 @@ public static function getAdditionalConfigFiles(): array
 		return [
 			__DIR__ . '/../../../conf/bleedingEdge.neon',
 			__DIR__ . '/typeAliases.neon',
+			__DIR__ . '/gnsr-extensions.neon',
 		];
 	}
 

tests/PHPStan/Analyser/gnsr-extensions.neon

@@ -0,0 +1,5 @@
+services:
+	-
+		class: PHPStan\Build\GeneratorYieldSendTypeExtension
+		tags:
+			- phpstan.broker.expressionTypeResolverExtension

tests/PHPStan/Analyser/nsrt/gnsr-yield-in-generator-ns.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace PHPStan\Analyser\Generator;
+
+use Generator;
+use function PHPStan\Testing\assertType;
+
+class FooTestYield
+{
+
+	/**
+	 * @return Generator<int, ExprAnalysisRequest|StmtAnalysisRequest|StmtsAnalysisRequest|NodeCallbackRequest, ExprAnalysisResult|StmtAnalysisResult, StmtAnalysisResult>
+	 */
+	public function doFoo(): Generator
+	{
+		assertType(ExprAnalysisResult::class, yield new ExprAnalysisRequest());
+		assertType(StmtAnalysisResult::class, yield new StmtAnalysisRequest());
+		assertType(StmtAnalysisResult::class, yield new StmtsAnalysisRequest());
+		assertType('null', yield new NodeCallbackRequest());
+	}
+
+}