Avoid duplicate in union type description

src/Type/UnionType.php

@@ -293,6 +293,8 @@ public function describe(VerbosityLevel $level): string
 				}
 			}
 
+			$typeNames = array_unique($typeNames);
+
 			if (count($typeNames) > 1024) {
 				return implode('|', array_slice($typeNames, 0, 1024)) . "|\u{2026}";
 			}

tests/PHPStan/Type/UnionTypeTest.php

@@ -21,6 +21,7 @@
 use PHPStan\Type\Constant\ConstantFloatType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\data\QueryType;
 use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\GenericClassStringType;
 use PHPStan\Type\Generic\GenericObjectType;
@@ -915,6 +916,11 @@ public function dataDescribe(): array
 				'(TFoo of TBar)|null',
 				'(TFoo of TBar)|null',
 			],
+			[
+				new UnionType([new QueryType('foo'), new QueryType('bar')]),
+				'Doctrine\ORM\Query<mixed, mixed>',
+				'Doctrine\ORM\Query<mixed, mixed>',
+			]
 		];
 	}
 

tests/PHPStan/Type/data/QueryType.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace PHPStan\Type\data;
+
+use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\Type;
+
+class QueryType extends GenericObjectType
+{
+	/** @var Type */
+	private $indexType;
+
+	/** @var Type */
+	private $resultType;
+
+	/** @var string */
+	private $dql;
+
+	public function __construct(string $dql, ?Type $indexType = null, ?Type $resultType = null, ?Type $subtractedType = null)
+	{
+		$this->indexType = $indexType ?? new MixedType();
+		$this->resultType = $resultType ?? new MixedType();
+
+		parent::__construct('Doctrine\ORM\Query', [
+			$this->indexType,
+			$this->resultType,
+		], $subtractedType);
+
+		$this->dql = $dql;
+	}
+
+	public function getDql(): string {
+		return $this->dql;
+	}
+
+	public function equals(Type $type): bool
+	{
+		if ($type instanceof self) {
+			return $this->getDql() === $type->getDql();
+		}
+
+		return parent::equals($type);
+	}
+
+}