diff core/tests/Drupal/Tests/Component/Graph/GraphTest.php @ 0:c75dbcec494b

Initial commit from drush-created site

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/tests/Drupal/Tests/Component/Graph/GraphTest.php	Thu Jul 05 14:24:15 2018 +0000
@@ -0,0 +1,191 @@
+<?php
+
+namespace Drupal\Tests\Component\Graph;
+
+use Drupal\Component\Graph\Graph;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Component\Graph\Graph
+ * @group Graph
+ */
+class GraphTest extends TestCase {
+
+  /**
+   * Test depth-first-search features.
+   */
+  public function testDepthFirstSearch() {
+    // The sample graph used is:
+    // 1 --> 2 --> 3     5 ---> 6
+    //       |     ^     ^
+    //       |     |     |
+    //       |     |     |
+    //       +---> 4 <-- 7      8 ---> 9
+    $graph = $this->normalizeGraph([
+      1 => [2],
+      2 => [3, 4],
+      3 => [],
+      4 => [3],
+      5 => [6],
+      7 => [4, 5],
+      8 => [9],
+      9 => [],
+    ]);
+    $graph_object = new Graph($graph);
+    $graph = $graph_object->searchAndSort();
+
+    $expected_paths = [
+      1 => [2, 3, 4],
+      2 => [3, 4],
+      3 => [],
+      4 => [3],
+      5 => [6],
+      7 => [4, 3, 5, 6],
+      8 => [9],
+      9 => [],
+    ];
+    $this->assertPaths($graph, $expected_paths);
+
+    $expected_reverse_paths = [
+      1 => [],
+      2 => [1],
+      3 => [2, 1, 4, 7],
+      4 => [2, 1, 7],
+      5 => [7],
+      7 => [],
+      8 => [],
+      9 => [8],
+    ];
+    $this->assertReversePaths($graph, $expected_reverse_paths);
+
+    // Assert that DFS didn't created "missing" vertexes automatically.
+    $this->assertFalse(isset($graph[6]), 'Vertex 6 has not been created');
+
+    $expected_components = [
+      [1, 2, 3, 4, 5, 7],
+      [8, 9],
+    ];
+    $this->assertComponents($graph, $expected_components);
+
+    $expected_weights = [
+      [1, 2, 3],
+      [2, 4, 3],
+      [7, 4, 3],
+      [7, 5],
+      [8, 9],
+    ];
+    $this->assertWeights($graph, $expected_weights);
+  }
+
+  /**
+   * Normalizes a graph.
+   *
+   * @param $graph
+   *   A graph array processed by \Drupal\Component\Graph\Graph::searchAndSort()
+   *
+   * @return array
+   *   The normalized version of a graph.
+   */
+  protected function normalizeGraph($graph) {
+    $normalized_graph = [];
+    foreach ($graph as $vertex => $edges) {
+      // Create vertex even if it hasn't any edges.
+      $normalized_graph[$vertex] = [];
+      foreach ($edges as $edge) {
+        $normalized_graph[$vertex]['edges'][$edge] = TRUE;
+      }
+    }
+    return $normalized_graph;
+  }
+
+  /**
+   * Verify expected paths in a graph.
+   *
+   * @param $graph
+   *   A graph array processed by \Drupal\Component\Graph\Graph::searchAndSort()
+   * @param $expected_paths
+   *   An associative array containing vertices with their expected paths.
+   */
+  protected function assertPaths($graph, $expected_paths) {
+    foreach ($expected_paths as $vertex => $paths) {
+      // Build an array with keys = $paths and values = TRUE.
+      $expected = array_fill_keys($paths, TRUE);
+      $result = isset($graph[$vertex]['paths']) ? $graph[$vertex]['paths'] : [];
+      $this->assertEquals($expected, $result, sprintf('Expected paths for vertex %s: %s, got %s', $vertex, $this->displayArray($expected, TRUE), $this->displayArray($result, TRUE)));
+    }
+  }
+
+  /**
+   * Verify expected reverse paths in a graph.
+   *
+   * @param $graph
+   *   A graph array processed by \Drupal\Component\Graph\Graph::searchAndSort()
+   * @param $expected_reverse_paths
+   *   An associative array containing vertices with their expected reverse
+   *   paths.
+   */
+  protected function assertReversePaths($graph, $expected_reverse_paths) {
+    foreach ($expected_reverse_paths as $vertex => $paths) {
+      // Build an array with keys = $paths and values = TRUE.
+      $expected = array_fill_keys($paths, TRUE);
+      $result = isset($graph[$vertex]['reverse_paths']) ? $graph[$vertex]['reverse_paths'] : [];
+      $this->assertEquals($expected, $result, sprintf('Expected reverse paths for vertex %s: %s, got %s', $vertex, $this->displayArray($expected, TRUE), $this->displayArray($result, TRUE)));
+    }
+  }
+
+  /**
+   * Verify expected components in a graph.
+   *
+   * @param $graph
+   *   A graph array processed by \Drupal\Component\Graph\Graph::searchAndSort().
+   * @param $expected_components
+   *   An array containing of components defined as a list of their vertices.
+   */
+  protected function assertComponents($graph, $expected_components) {
+    $unassigned_vertices = array_fill_keys(array_keys($graph), TRUE);
+    foreach ($expected_components as $component) {
+      $result_components = [];
+      foreach ($component as $vertex) {
+        $result_components[] = $graph[$vertex]['component'];
+        unset($unassigned_vertices[$vertex]);
+      }
+      $this->assertEquals(1, count(array_unique($result_components)), sprintf('Expected one unique component for vertices %s, got %s', $this->displayArray($component), $this->displayArray($result_components)));
+    }
+    $this->assertEquals([], $unassigned_vertices, sprintf('Vertices not assigned to a component: %s', $this->displayArray($unassigned_vertices, TRUE)));
+  }
+
+  /**
+   * Verify expected order in a graph.
+   *
+   * @param $graph
+   *   A graph array processed by \Drupal\Component\Graph\Graph::searchAndSort()
+   * @param $expected_orders
+   *   An array containing lists of vertices in their expected order.
+   */
+  protected function assertWeights($graph, $expected_orders) {
+    foreach ($expected_orders as $order) {
+      $previous_vertex = array_shift($order);
+      foreach ($order as $vertex) {
+        $this->assertTrue($graph[$previous_vertex]['weight'] < $graph[$vertex]['weight'], sprintf('Weights of %s and %s are correct relative to each other', $previous_vertex, $vertex));
+      }
+    }
+  }
+
+  /**
+   * Helper function to output vertices as comma-separated list.
+   *
+   * @param $paths
+   *   An array containing a list of vertices.
+   * @param $keys
+   *   (optional) Whether to output the keys of $paths instead of the values.
+   */
+  protected function displayArray($paths, $keys = FALSE) {
+    if (!empty($paths)) {
+      return implode(', ', $keys ? array_keys($paths) : $paths);
+    }
+    else {
+      return '(empty)';
+    }
+  }
+
+}