Add support for union type comparison

Author: tomzx

src/PHPSemVerChecker/Comparator/Type.php

@@ -4,6 +4,7 @@
 namespace PHPSemVerChecker\Comparator;
 
 use PhpParser\Node\NullableType;
+use PhpParser\Node\UnionType;
 
 class Type
 {
@@ -20,17 +21,27 @@ public static function isSame($typeA, $typeB): bool
 	}
 
 	/**
-	 * @param \PhpParser\Node\Name|\PhpParser\Node\NullableType|string|null $type
+	 * @param \PhpParser\Node\Name|\PhpParser\Node\NullableType|\PhpParser\Node\UnionType|string|null $type
 	 * @return string|null
 	 */
-	public static function get($type)
+	public static function get($type): ?string
 	{
-		if (! is_object($type)) {
+		if ( ! is_object($type)) {
 			return $type;
 		}
 
 		if ($type instanceof NullableType) {
-			return '?'.static::get($type->type);
+			return '?' . static::get($type->type);
+		}
+
+		if ($type instanceof UnionType) {
+			$types = [];
+			foreach ($type->types as $unionType) {
+				$types[] = static::get($unionType);
+			}
+			// Sort to ensure consistent comparison even with different order of types
+			sort($types);
+			return implode('|', $types);
 		}
 
 		return $type->toString();

tests/PHPSemVerChecker/Comparator/TypeComparatorTest.php

@@ -2,8 +2,10 @@
 
 namespace PHPSemVerChecker\Test\Comparator;
 
+use PhpParser\Node\Identifier;
 use PhpParser\Node\Name;
 use PhpParser\Node\NullableType;
+use PhpParser\Node\UnionType;
 use PHPSemVerChecker\Comparator\Type;
 use PHPSemVerChecker\Test\TestCase;
 
@@ -22,7 +24,8 @@ public function isSameProvider()
 		return [
 			[Name::concat(null, 'test'), Name::concat(null, 'test')],
 			['test', 'test'],
-			[null, null]
+			[null, null],
+			[new UnionType([new Identifier('self'), new Identifier('array')]), new UnionType([new Identifier('array'), new Identifier('self')])],
 		];
 	}
 
@@ -39,7 +42,8 @@ public function isNotSameProvider()
 		return [
 			[Name::concat(null, 'test'), Name::concat(null, 'test1')],
 			['test', 'test1'],
-			[null, 'test']
+			[null, 'test'],
+			[new UnionType([new Identifier('self'), new Identifier('array')]), null],
 		];
 	}
 
@@ -59,6 +63,7 @@ public function getProvider()
 			[Name::concat('namespaced', 'test'), 'namespaced\test'],
 			[new NullableType('test'), '?test'],
 			[new NullableType(Name::concat('namespaced', 'test')), '?namespaced\test'],
+			[new UnionType([new Identifier('self'), new Identifier('array')]), 'array|self'],
 		];
 	}
 }