class DiscoveryCachedTraitTest

class DiscoveryCachedTraitTest extends TestCase {
  
  /**
   * Data provider for testGetDefinition().
   *
   * @return array
   *   - Expected result from getDefinition().
   *   - Cached definitions to be placed into self::$definitions
   *   - Definitions to be returned by getDefinitions().
   *   - Plugin name to query for.
   */
  public static function providerGetDefinition() {
    return [
      [
        'definition',
        [],
        [
          'plugin_name' => 'definition',
        ],
        'plugin_name',
      ],
      [
        'definition',
        [
          'plugin_name' => 'definition',
        ],
        [],
        'plugin_name',
      ],
      [
        NULL,
        [
          'plugin_name' => 'definition',
        ],
        [],
        'bad_plugin_name',
      ],
    ];
  }
  
  /**
   * @covers ::getDefinition
   * @dataProvider providerGetDefinition
   */
  public function testGetDefinition($expected, $cached_definitions, $get_definitions, $plugin_id) : void {
    $trait = $this->getMockBuilder(DiscoveryCachedTraitMockableClass::class)
      ->onlyMethods([
      'getDefinitions',
    ])
      ->getMock();
    $reflection_definitions = new \ReflectionProperty($trait, 'definitions');
    // getDefinition() needs the ::$definitions property to be set in one of two
    // ways: 1) As existing cached data, or 2) as a side-effect of calling
    // getDefinitions().
    // If there are no cached definitions, then we have to fake the side-effect
    // of getDefinitions().
    if (count($cached_definitions) < 1) {
      $trait->expects($this->once())
        ->method('getDefinitions')
        ->willReturnCallback(function () use ($reflection_definitions, $trait, $get_definitions) {
        $reflection_definitions->setValue($trait, $get_definitions);
        return $get_definitions;
      });
    }
    else {
      // Put $cached_definitions into our mocked ::$definitions.
      $reflection_definitions->setValue($trait, $cached_definitions);
    }
    // Call getDefinition(), with $exception_on_invalid always FALSE.
    $this->assertSame($expected, $trait->getDefinition($plugin_id, FALSE));
  }

}