Fix MixedType->equals(ErrorType)

Author: staabm

src/Type/MixedType.php

@@ -37,6 +37,7 @@
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
 use PHPStan\Type\Traits\NonGenericTypeTrait;
 use PHPStan\Type\Traits\UndecidedComparisonCompoundTypeTrait;
+use function get_class;
 use function sprintf;
 
 /** @api */
@@ -319,7 +320,7 @@ public function getCallableParametersAcceptors(ClassMemberAccessAnswerer $scope)
 
 public function equals(Type $type): bool
 {
-if (!$type instanceof self) {
+if (get_class($type) !== static::class) {
 return false;
 }
 

tests/PHPStan/Generics/TemplateTypeFactoryTest.php

@@ -56,7 +56,12 @@ public static function dataCreate(): array
 null,
 TemplateTypeVariance::createInvariant(),
 ),
-new MixedType(),
+TemplateTypeFactory::create(
+TemplateTypeScope::createWithFunction('a'),
+'U',
+null,
+TemplateTypeVariance::createInvariant(),
+),
 ],
 [
 new UnionType([

tests/PHPStan/Type/MixedTypeTest.php

@@ -1129,4 +1129,50 @@ public function testSubtractedHasOffsetValueType(MixedType $mixedType, Type $typ
 );
 }
 
+/** @dataProvider dataEquals */
+public function testEquals(MixedType $mixedType, Type $typeToCompare, bool $expectedResult): void
+{
+$this->assertSame(
+$expectedResult,
+$mixedType->equals($typeToCompare),
+sprintf('%s -> equals(%s)', $mixedType->describe(VerbosityLevel::precise()), $typeToCompare->describe(VerbosityLevel::precise())),
+);
+}
+
+public function dataEquals(): array
+{
+return [
+[
+new MixedType(),
+new MixedType(),
+true,
+],
+[
+new MixedType(true),
+new MixedType(),
+true,
+],
+[
+new MixedType(),
+new MixedType(true),
+true,
+],
+[
+new MixedType(),
+new MixedType(true, new IntegerType()),
+false,
+],
+[
+new MixedType(),
+new ErrorType(),
+false,
+],
+[
+new MixedType(true),
+new ErrorType(),
+false,
+],
+];
+}
+
 }