3.0 - QueryBuilder - multi-select is not supported

[ondrejmirtes]

Bug Report

Q	A
BC Break	yes
Version	3.0

Summary

I'm working on ORM 3 and DBAL 4 support on phpstan-doctrine, and I have this test case:

		$this->entityManager->createQueryBuilder()
			->select([
				'e.id',
				'e.title',
			])->from(MyEntity::class, 'e')
			->getQuery();

When this method is called, Doctrine crashes with: Cannot use "::class" on array originating here:

• orm/src/Query/Expr/Base.php

  Line 63 in 5a40b99

  if (! is_string($arg) && ! in_array($arg::class, $this->allowedClasses, true)) {

• orm/src/Query/Expr/Base.php

  Line 48 in 5a40b99

  $this->add($arg);

• orm/src/Query/Expr/Base.php

  Line 36 in 5a40b99

  $this->addMultiple($args);

• orm/src/QueryBuilder.php

  Line 620 in 5a40b99

  return $this->add('select', new Expr\Select($select), false);

This is how $select looks like when coming into new Expr\Select($select):

array(1) {
  [0]=>
  array(2) {
    [0]=>
    string(4) "e.id"
    [1]=>
    string(7) "e.title"
  }
}

Current behavior

The method throws an exception.

Expected behavior

It should work because even current 3.0 documentation mentions the possibility to pass arrays into the select method: https://www.doctrine-project.org/projects/doctrine-orm/en/3.0/reference/query-builder.html#high-level-api-methods