class MenuLinkTreeTest

class MenuLinkTreeTest extends UnitTestCase {
    
    /**
     * The tested menu link tree service.
     *
     * @var \Drupal\Core\Menu\MenuLinkTree
     */
    protected $menuLinkTree;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $this->menuLinkTree = new MenuLinkTree($this->createMock('\\Drupal\\Core\\Menu\\MenuTreeStorageInterface'), $this->createMock('\\Drupal\\Core\\Menu\\MenuLinkManagerInterface'), $this->createMock('\\Drupal\\Core\\Routing\\RouteProviderInterface'), $this->createMock('\\Drupal\\Core\\Menu\\MenuActiveTrailInterface'), $this->createMock(CallableResolver::class));
        $cache_contexts_manager = $this->getMockBuilder('Drupal\\Core\\Cache\\Context\\CacheContextsManager')
            ->disableOriginalConstructor()
            ->getMock();
        $cache_contexts_manager->method('assertValidTokens')
            ->willReturn(TRUE);
        $container = new ContainerBuilder();
        $container->set('cache_contexts_manager', $cache_contexts_manager);
        \Drupal::setContainer($container);
    }
    
    /**
     * @covers ::build
     *
     * MenuLinkTree::build() gathers both:
     * 1. the tree's access cacheability: the cacheability of the access result
     *    of checking a link in a menu tree's access. Callers can opt out of
     *    this by MenuLinkTreeElement::access to NULL (the default) value, in
     *    which case the menu link is always visible. Only when an
     *    AccessResultInterface object is specified, we gather this cacheability
     *    metadata.
     *    This means there are three cases:
     *    a. no access result (NULL): menu link is visible
     *    b. AccessResultInterface object that is allowed: menu link is visible
     *    c. AccessResultInterface object that is not allowed: menu link is
     *       invisible, but cacheability metadata is still applicable
     * 2. the tree's menu links' cacheability: the cacheability of a menu link
     *    itself, because it may be dynamic. For this reason, MenuLinkInterface
     *    extends CacheableDependencyInterface. It allows any menu link plugin to
     *    mark itself as uncacheable (max-age=0) or dynamic (by specifying cache
     *    tags and/or contexts), to indicate the extent of dynamism.
     *    This means there are two cases:
     *    a. permanently cacheable, no cache tags, no cache contexts
     *    b. anything else: non-permanently cacheable, and/or cache tags, and/or
     *       cache contexts.
     *
     * Finally, there are four important shapes of trees, all of which we want to
     * test:
     * 1. the empty tree
     * 2. a single-element tree
     * 3. a single-level tree (>1 element; just 1 element is case 2)
     * 4. a multi-level tree
     *
     * The associated data provider aims to test the handling of both of these
     * types of cacheability, and for all four tree shapes, for each of the types
     * of values for the two types of cacheability.
     *
     * There is another level of cacheability involved when actually rendering
     * built menu trees (i.e. when invoking RendererInterface::render() on the
     * return value of MenuLinkTreeInterface::build()): the cacheability of the
     * generated URLs.
     * Fortunately, that doesn't need additional test coverage here because that
     * cacheability is handled at the level of the Renderer (i.e. menu.html.twig
     * template's link() function invocation). It also has its own test coverage.
     *
     * @see \Drupal\menu_link_content\Tests\MenuLinkContentCacheabilityBubblingTest
     *
     * @dataProvider providerTestBuildCacheability
     */
    public function testBuildCacheability($description, $tree, $expected_build, $access, array $access_cache_contexts = []) : void {
        if ($access !== NULL) {
            $access->addCacheContexts($access_cache_contexts);
        }
        $build = $this->menuLinkTree
            ->build($tree);
        $this->assertEquals($expected_build, $build, $description);
    }
    
    /**
     * Provides the test cases to test for ::testBuildCacheability().
     *
     * As explained in the documentation for ::testBuildCacheability(), this
     * generates 1 + (3 * 2 * 3) = 19 test cases.
     *
     * @see testBuildCacheability
     */
    public static function providerTestBuildCacheability() {
        $base_expected_build_empty = [
            '#cache' => [
                'contexts' => [],
                'tags' => [],
                'max-age' => Cache::PERMANENT,
            ],
        ];
        $base_expected_build = [
            '#cache' => [
                'contexts' => [],
                'tags' => [
                    'config:system.menu.mock',
                ],
                'max-age' => Cache::PERMANENT,
            ],
            '#sorted' => TRUE,
            '#menu_name' => 'mock',
            '#theme' => 'menu__mock',
            '#items' => [],
        ];
        $get_built_element = function (MenuLinkTreeElement $element) {
            $return = [
                'attributes' => new Attribute(),
                'title' => $element->link
                    ->getTitle(),
                'url' => new Url($element->link
                    ->getRouteName(), $element->link
                    ->getRouteParameters(), [
                    'set_active_class' => TRUE,
                ]),
                'below' => [],
                'original_link' => $element->link,
                'is_expanded' => FALSE,
                'is_collapsed' => FALSE,
                'in_active_trail' => FALSE,
            ];
            if ($element->hasChildren && !empty($element->subtree)) {
                $return['is_expanded'] = TRUE;
            }
            elseif ($element->hasChildren) {
                $return['is_collapsed'] = TRUE;
            }
            if ($element->inActiveTrail) {
                $return['in_active_trail'] = TRUE;
            }
            return $return;
        };
        // The three access scenarios described in this method's documentation.
        $access_scenarios = [
            [
                NULL,
                [],
            ],
            [
                AccessResult::allowed(),
                [
                    'access:allowed',
                ],
            ],
            [
                AccessResult::neutral(),
                [
                    'access:neutral',
                ],
            ],
        ];
        // The two links scenarios described in this method's documentation.
        $cache_defaults = [
            'cache_max_age' => Cache::PERMANENT,
            'cache_tags' => [],
        ];
        $links_scenarios = [
            [
                MenuLinkMock::create([
                    'id' => 'test.example1',
                    'route_name' => 'example1',
                    'title' => 'Example 1',
                ]),
                MenuLinkMock::create([
                    'id' => 'test.example2',
                    'route_name' => 'example1',
                    'title' => 'Example 2',
                    'metadata' => [
                        'cache_contexts' => [
                            'llama',
                        ],
                    ] + $cache_defaults,
                ]),
            ],
            [
                MenuLinkMock::create([
                    'id' => 'test.example1',
                    'route_name' => 'example1',
                    'title' => 'Example 1',
                    'metadata' => [
                        'cache_contexts' => [
                            'foo',
                        ],
                    ] + $cache_defaults,
                ]),
                MenuLinkMock::create([
                    'id' => 'test.example2',
                    'route_name' => 'example1',
                    'title' => 'Example 2',
                    'metadata' => [
                        'cache_contexts' => [
                            'bar',
                        ],
                    ] + $cache_defaults,
                ]),
            ],
        ];
        $data = [];
        // Empty tree.
        $data[] = [
            'description' => 'Empty tree.',
            'tree' => [],
            'expected_build' => $base_expected_build_empty,
            'access' => NULL,
            'access_cache_contexts' => [],
        ];
        for ($i = 0; $i < count($access_scenarios); $i++) {
            [
                $access,
                $access_cache_contexts,
            ] = $access_scenarios[$i];
            for ($j = 0; $j < count($links_scenarios); $j++) {
                $links = $links_scenarios[$j];
                // Single-element tree.
                $tree = [
                    new MenuLinkTreeElement($links[0], FALSE, 0, FALSE, []),
                ];
                $tree[0]->access = $access;
                if ($access === NULL || $access->isAllowed()) {
                    $expected_build = $base_expected_build;
                    $expected_build['#items']['test.example1'] = $get_built_element($tree[0]);
                }
                else {
                    $expected_build = $base_expected_build_empty;
                }
                $expected_build['#cache']['contexts'] = array_merge($expected_build['#cache']['contexts'], $access_cache_contexts, $links[0]->getCacheContexts());
                $data[] = [
                    'description' => "Single-item tree; access={$i}; link={$j}.",
                    'tree' => $tree,
                    'expected_build' => $expected_build,
                    'access' => $access,
                    'access_cache_contexts' => $access_cache_contexts,
                ];
                // Single-level tree.
                $tree = [
                    new MenuLinkTreeElement($links[0], FALSE, 0, FALSE, []),
                    new MenuLinkTreeElement($links[1], FALSE, 0, FALSE, []),
                ];
                $tree[0]->access = $access;
                $expected_build = $base_expected_build;
                if ($access === NULL || $access->isAllowed()) {
                    $expected_build['#items']['test.example1'] = $get_built_element($tree[0]);
                }
                $expected_build['#items']['test.example2'] = $get_built_element($tree[1]);
                $expected_build['#cache']['contexts'] = array_merge($expected_build['#cache']['contexts'], $access_cache_contexts, $links[0]->getCacheContexts(), $links[1]->getCacheContexts());
                $data[] = [
                    'description' => "Single-level tree; access={$i}; link={$j}.",
                    'tree' => $tree,
                    'expected_build' => $expected_build,
                    'access' => $access,
                    'access_cache_contexts' => $access_cache_contexts,
                ];
                // Multi-level tree.
                $multi_level_root_a = MenuLinkMock::create([
                    'id' => 'test.root_a',
                    'route_name' => 'root_a',
                    'title' => 'Root A',
                ]);
                $multi_level_root_b = MenuLinkMock::create([
                    'id' => 'test.root_b',
                    'route_name' => 'root_b',
                    'title' => 'Root B',
                ]);
                $multi_level_parent_c = MenuLinkMock::create([
                    'id' => 'test.parent_c',
                    'route_name' => 'parent_c',
                    'title' => 'Parent C',
                ]);
                $tree = [
                    new MenuLinkTreeElement($multi_level_root_a, TRUE, 0, FALSE, [
                        new MenuLinkTreeElement($multi_level_parent_c, TRUE, 0, FALSE, [
                            new MenuLinkTreeElement($links[0], FALSE, 0, FALSE, []),
                        ]),
                    ]),
                    new MenuLinkTreeElement($multi_level_root_b, TRUE, 0, FALSE, [
                        new MenuLinkTreeElement($links[1], FALSE, 1, FALSE, []),
                    ]),
                ];
                $tree[0]->subtree[0]->subtree[0]->access = $access;
                $expected_build = $base_expected_build;
                $expected_build['#items']['test.root_a'] = $get_built_element($tree[0]);
                $expected_build['#items']['test.root_a']['below']['test.parent_c'] = $get_built_element($tree[0]->subtree[0]);
                if ($access === NULL || $access->isAllowed()) {
                    $expected_build['#items']['test.root_a']['below']['test.parent_c']['below']['test.example1'] = $get_built_element($tree[0]->subtree[0]->subtree[0]);
                }
                $expected_build['#items']['test.root_b'] = $get_built_element($tree[1]);
                $expected_build['#items']['test.root_b']['below']['test.example2'] = $get_built_element($tree[1]->subtree[0]);
                $expected_build['#cache']['contexts'] = array_merge($expected_build['#cache']['contexts'], $access_cache_contexts, $links[0]->getCacheContexts(), $links[1]->getCacheContexts());
                $data[] = [
                    'description' => "Multi-level tree; access={$i}; link={$j}.",
                    'tree' => $tree,
                    'expected_build' => $expected_build,
                    'access' => $access,
                    'access_cache_contexts' => $access_cache_contexts,
                ];
            }
        }
        return $data;
    }

}