ImplodeFunctionReturnTypeExtension - fix handling optional keys in Co…

…nstantArrayType

src/Type/Php/ImplodeFunctionReturnTypeExtension.php

@@ -14,6 +14,7 @@
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
 use function count;
 use function implode;
 use function in_array;
@@ -83,17 +84,22 @@ private function implode(Type $arrayType, Type $separatorType): Type
 
 	private function inferConstantType(ConstantArrayType $arrayType, ConstantStringType $separatorType): ?Type
 	{
-		$valueTypes = $arrayType->getValueTypes();
-
-		$arrayValues = [];
-		foreach ($valueTypes as $valueType) {
-			if (!$valueType instanceof ConstantScalarType) {
-				return null;
+		$strings = [];
+		foreach ($arrayType->getAllArrays() as $array) {
+			$valueTypes = $array->getValueTypes();
+
+			$arrayValues = [];
+			foreach ($valueTypes as $valueType) {
+				if (!$valueType instanceof ConstantScalarType) {
+					return null;
+				}
+				$arrayValues[] = $valueType->getValue();
 			}
-			$arrayValues[] = $valueType->getValue();
+
+			$strings[] = new ConstantStringType(implode($separatorType->getValue(), $arrayValues));
 		}
 
-		return new ConstantStringType(implode($separatorType->getValue(), $arrayValues));
+		return TypeCombinator::union(...$strings);
 	}
 
 }

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -749,6 +749,7 @@ public function dataFileAsserts(): iterable
 		}
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6699.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6715.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-6715.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Bug6715;
+
+use function PHPStan\Testing\assertType;
+
+class Test
+{
+	/** @var bool */
+	public $bool;
+
+	function test(): void
+	{
+		assertType('array{test: true}', array_filter([
+			'test' => true,
+		]));
+
+		assertType('array{}', array_filter([
+			'test' => false,
+		]));
+
+		assertType('array{test?: 1}', array_filter([
+			'test' => rand(0, 1),
+		]));
+
+		assertType('array{test?: true}', array_filter([
+			'test' => $this->bool,
+		]));
+	}
+
+	function test2(): void
+	{
+		assertType('\'1\'', implode(', ', array_filter([
+			'test' => true,
+		])));
+
+		assertType('\'\'', implode(', ', array_filter([
+			'test' => false,
+		])));
+
+		assertType('\'\'|\'1\'', implode(', ', array_filter([
+			'test' => rand(0, 1),
+		])));
+
+		assertType('\'\'|\'1\'', implode(', ', array_filter([
+			'test' => $this->bool,
+		])));
+	}
+}