Simplify and improve solution

Author: herndlm

phpstan-baseline.neon

@@ -1470,7 +1470,7 @@ parameters:
 		-
 			message: '#^Doing instanceof PHPStan\\Type\\Constant\\ConstantArrayType is error\-prone and deprecated\. Use Type\:\:getConstantArrays\(\) instead\.$#'
 			identifier: phpstanApi.instanceofType
-			count: 2
+			count: 1
 			path: src/Type/Php/ArrayMergeFunctionDynamicReturnTypeExtension.php
 
 		-

src/Type/Php/ArrayMergeFunctionDynamicReturnTypeExtension.php

@@ -5,14 +5,14 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryArrayListType;
 use PHPStan\Type\Accessory\NonEmptyArrayType;
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
 use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\NeverType;
@@ -72,22 +72,19 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 		if ($allConstant->yes()) {
 			$newArrayBuilder = ConstantArrayTypeBuilder::createEmpty();
 			foreach ($argTypes as $argType) {
-				$constantArrayType = $this->untagConstantArrayUnion($argType);
-				if (!$constantArrayType instanceof ConstantArrayType) {
-					throw new ShouldNotHappenException();
+				/** @var array<int|string, ConstantIntegerType|ConstantStringType> $keyTypes */
+				$keyTypes = [];
+				foreach ($argType->getConstantArrays() as $constantArray) {
+					foreach ($constantArray->getKeyTypes() as $keyType) {
+						$keyTypes[$keyType->getValue()] = $keyType;
+					}
 				}
 
-				$keyTypes = $constantArrayType->getKeyTypes();
-				$valueTypes = $constantArrayType->getValueTypes();
-				$optionalKeys = $constantArrayType->getOptionalKeys();
-
-				foreach ($keyTypes as $k => $keyType) {
-					$isOptional = in_array($k, $optionalKeys, true);
-
+				foreach ($keyTypes as $keyType) {
 					$newArrayBuilder->setOffsetValueType(
 						$keyType instanceof ConstantIntegerType ? null : $keyType,
-						$valueTypes[$k],
-						$isOptional,
+						$argType->getOffsetValueType($keyType),
+						!$argType->hasOffsetValueType($keyType)->yes(),
 					);
 				}
 			}
@@ -135,29 +132,4 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 		return $arrayType;
 	}
 
-	/**
-	 * array{0: 17, foo: 'bar'}|array{0: 19, foo: 'bar', fofoo: 'barbar'}
-	 * ->
-	 * array{0: 17|19, foo: 'bar', foofo?: 'barbar'}
-	 */
-	private function untagConstantArrayUnion(Type $constantArrayType): Type
-	{
-		$constantArrayTypes = $constantArrayType->getConstantArrays();
-		if (count($constantArrayTypes) === 1) {
-			return $constantArrayTypes[0];
-		}
-
-		$builder = ConstantArrayTypeBuilder::createEmpty();
-		$keyTypes = $constantArrayType->getKeysArray()->getIterableValueType()->getFiniteTypes();
-		foreach ($keyTypes as $keyType) {
-			$builder->setOffsetValueType(
-				$keyType,
-				$constantArrayType->getOffsetValueType($keyType),
-				!$constantArrayType->hasOffsetValueType($keyType)->yes(),
-			);
-		}
-
-		return $builder->getArray();
-	}
-
 }

tests/PHPStan/Analyser/nsrt/array-merge2.php

@@ -21,7 +21,7 @@ public function arrayMergeArrayShapes($array1, $array2): void
 		assertType("array{foo: '1', bar: '2', lall2: '3', 0: '4', 1: '6', lall: '3', 2: '2', 3: '3'}", array_merge($array2, $array1));
 		assertType("array{foo: 3, bar: '2', lall2: '3', 0: '4', 1: '6', lall: '3', 2: '2', 3: '3'}", array_merge($array2, $array1, ['foo' => 3]));
 		assertType("array{foo: 3, bar: '2', lall2: '3', 0: '4', 1: '6', lall: '3', 2: '2', 3: '3'}", array_merge($array2, $array1, ...[['foo' => 3]]));
-		assertType("array{foo: '1', bar: '2'|'4', lall2?: '3', lall?: '3', 0: '2'|'4', 1: '3'|'6'}", array_merge(rand(0, 1) ? $array1 : $array2, []));
+		assertType("array{foo: '1', bar: '2'|'4', lall?: '3', 0: '2'|'4', 1: '3'|'6', lall2?: '3'}", array_merge(rand(0, 1) ? $array1 : $array2, []));
 		assertType("array{foo?: 3, bar?: 3}", array_merge([], ...[rand(0, 1) ? ['foo' => 3] : ['bar' => 3]]));
 	}