added checks for yield from also

dktapps · ondrejmirtes · commit 04de69afcdb9 · 2020-08-30T20:20:23.000+02:00
diff --git a/src/Rules/Generators/YieldFromTypeRule.php b/src/Rules/Generators/YieldFromTypeRule.php
@@ -13,6 +13,7 @@
 use PHPStan\Type\MixedType;
 use PHPStan\Type\TypeWithClassName;
 use PHPStan\Type\VerbosityLevel;
+use PHPStan\Type\VoidType;
 
 /**
  * @implements \PHPStan\Rules\Rule<\PhpParser\Node\Expr\YieldFrom>
@@ -130,6 +131,10 @@ public function processNode(Node $node, Scope $scope): array
 			))->build();
 		}
 
+		if ($scope->getType($node) instanceof VoidType && !$scope->isInFirstLevelStatement()) {
+			$messages[] = RuleErrorBuilder::message('Result of yield from (void) is used.')->build();
+		}
+
 		return $messages;
 	}
 
diff --git a/tests/PHPStan/Rules/Generators/YieldFromTypeRuleTest.php b/tests/PHPStan/Rules/Generators/YieldFromTypeRuleTest.php
@@ -40,6 +40,10 @@ public function testRule(): void
 				'Generator expects value type array(DateTime, DateTime, stdClass, DateTimeImmutable), array(0 => DateTime, 1 => DateTime, 2 => stdClass, 4 => DateTimeImmutable) given.',
 				74,
 			],
+			[
+				'Result of yield from (void) is used.',
+				111,
+			],
 		]);
 	}
 
diff --git a/tests/PHPStan/Rules/Generators/data/yield-from.php b/tests/PHPStan/Rules/Generators/data/yield-from.php
@@ -74,4 +74,40 @@ public function doArrayShape2(): \Generator
 		yield from $this->doArrayShape();
 	}
 
+	/**
+	 * @return \Generator<int, int>
+	 */
+	public function yieldWithImplicitReturn() : \Generator{
+		yield 1;
+		return 1;
+	}
+
+	/**
+	 * @return \Generator<int, int, void, int>
+	 */
+	public function yieldWithExplicitReturn() : \Generator{
+		yield 1;
+		return 1;
+	}
+
+	/**
+	 * @return \Generator<int, int, void, void>
+	 */
+	public function yieldWithVoidReturn() : \Generator{
+		yield 1;
+	}
+
+	/**
+	 * @return \Generator<int, int, void, void>
+	 */
+	public function yieldFromResult() : \Generator{
+		yield from $this->yieldWithImplicitReturn();
+		$mixed = yield from $this->yieldWithImplicitReturn();
+
+		yield from $this->yieldWithExplicitReturn();
+		$int = yield from $this->yieldWithExplicitReturn();
+
+		yield from $this->yieldWithVoidReturn();
+		$void = yield from $this->yieldWithVoidReturn();
+	}
 }
