class DiffEngineTest

class DiffEngineTest extends TestCase {
  use ExpectDeprecationTrait;
  
  /**
   * @return array
   *   - Expected output in terms of return class. A list of class names
   *     expected to be returned by DiffEngine::diff().
   *   - An array of strings to change from.
   *   - An array of strings to change to.
   */
  public static function provideTestDiff() {
    return [
      'empty' => [
        [],
        [],
        [],
      ],
      'add' => [
        [
          DiffOpAdd::class,
        ],
        [],
        [
          'a',
        ],
      ],
      'copy' => [
        [
          DiffOpCopy::class,
        ],
        [
          'a',
        ],
        [
          'a',
        ],
      ],
      'change' => [
        [
          DiffOpChange::class,
        ],
        [
          'a',
        ],
        [
          'b',
        ],
      ],
      'copy-and-change' => [
        [
          DiffOpCopy::class,
          DiffOpChange::class,
        ],
        [
          'a',
          'b',
        ],
        [
          'a',
          'c',
        ],
      ],
      'copy-change-copy' => [
        [
          DiffOpCopy::class,
          DiffOpChange::class,
          DiffOpCopy::class,
        ],
        [
          'a',
          'b',
          'd',
        ],
        [
          'a',
          'c',
          'd',
        ],
      ],
      'copy-change-copy-add' => [
        [
          DiffOpCopy::class,
          DiffOpChange::class,
          DiffOpCopy::class,
          DiffOpAdd::class,
        ],
        [
          'a',
          'b',
          'd',
        ],
        [
          'a',
          'c',
          'd',
          'e',
        ],
      ],
      'copy-delete' => [
        [
          DiffOpCopy::class,
          DiffOpDelete::class,
        ],
        [
          'a',
          'b',
          'd',
        ],
        [
          'a',
        ],
      ],
      'change-copy' => [
        [
          DiffOpChange::class,
          DiffOpCopy::class,
        ],
        [
          'aa',
          'bb',
          'cc',
          'd',
        ],
        [
          'a',
          'c',
          'd',
        ],
      ],
      'copy-change-copy-change' => [
        [
          DiffOpCopy::class,
          DiffOpChange::class,
          DiffOpCopy::class,
          DiffOpChange::class,
        ],
        [
          'a',
          'bb',
          'd',
          'ee',
        ],
        [
          'a',
          'b',
          'c',
          'd',
          'e',
        ],
      ],
    ];
  }
  
  /**
   * Tests whether op classes returned by DiffEngine::diff() match expectations.
   *
   * @covers ::diff
   * @dataProvider provideTestDiff
   */
  public function testDiff($expected, $from, $to) : void {
    $this->expectDeprecation('Drupal\\Component\\Diff\\Engine\\DiffEngine is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use sebastianbergmann/diff instead. See https://www.drupal.org/node/3337942');
    $diff_engine = new DiffEngine();
    $diff = $diff_engine->diff($from, $to);
    // Make sure we have the same number of results as expected.
    $this->assertSameSize($expected, $diff);
    // Make sure the diff objects match our expectations.
    foreach ($expected as $index => $op_class) {
      $this->assertEquals($op_class, get_class($diff[$index]));
    }
  }
  
  /**
   * Tests that two files can be successfully diffed.
   *
   * @covers ::diff
   */
  public function testDiffInfiniteLoop() : void {
    $this->expectDeprecation('Drupal\\Component\\Diff\\Engine\\DiffEngine is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use sebastianbergmann/diff instead. See https://www.drupal.org/node/3337942');
    $from = explode("\n", file_get_contents(__DIR__ . '/fixtures/file1.txt'));
    $to = explode("\n", file_get_contents(__DIR__ . '/fixtures/file2.txt'));
    $diff_engine = new DiffEngine();
    $diff = $diff_engine->diff($from, $to);
    $this->assertCount(4, $diff);
    $this->assertEquals($diff[0], new DiffOpDelete([
      '    - image.style.max_650x650',
    ]));
    $this->assertEquals($diff[1], new DiffOpCopy([
      '    - image.style.max_325x325',
    ]));
    $this->assertEquals($diff[2], new DiffOpAdd([
      '    - image.style.max_650x650',
      '_core:',
      '  default_config_hash: random_hash_string_here',
    ]));
    $this->assertEquals($diff[3], new DiffOpCopy([
      'fallback_image_style: max_325x325',
      '',
    ]));
  }

}