Short-circuit identical late-resolvable types in isSuperTypeOf and add coverage

Author: yt-catpaw

src/Type/Traits/LateResolvableTypeTrait.php

@@ -66,6 +66,18 @@ private function isSuperTypeOfDefault(Type $type): IsSuperTypeOfResult
 			return IsSuperTypeOfResult::createYes();
 		}
 
+		if ($this->equals($type)) {
+			return IsSuperTypeOfResult::createYes();
+		}
+
+		if ($type instanceof UnionType) {
+			foreach ($type->getTypes() as $innerType) {
+				if ($this->equals($innerType)) {
+					return IsSuperTypeOfResult::createYes();
+				}
+			}
+		}
+
 		if ($type instanceof LateResolvableType) {
 			$type = $type->resolve();
 		}

tests/PHPStan/Type/LateResolvableTypeTraitTest.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type;
+
+use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\IntegerType;
+use PHPStan\Type\NeverType;
+use PHPStan\Type\UnionType;
+use PHPUnit\Framework\TestCase;
+
+class LateResolvableTypeTraitTest extends TestCase
+{
+
+	public function testIsSuperTypeOfForConditional(): void
+	{
+		$conditional = new ConditionalTypeForParameter(
+			'$operator',
+			new ConstantStringType('in'),
+			new IntegerType(),
+			new NeverType(),
+			false,
+		);
+
+		$this->assertSame('Yes', $conditional->isSuperTypeOf($conditional)->describe());
+
+		$unionWithConditional = new UnionType([
+			new StringType(),
+			$conditional,
+		]);
+
+		$this->assertSame('Yes', $conditional->isSuperTypeOf($unionWithConditional)->describe());
+	}
+
+}