Fix fixture generation.

When generating fixtures don't add fixtures for self associated models.
Generally all instances of one class will use the same fixture and
including additional fixtures for aliases will only cause problems.

Refs #4440

src/Shell/Task/TestTask.php

@@ -335,9 +335,15 @@ protected function _processModel($subject) {
 		$this->_addFixture($subject->alias());
 		foreach ($subject->associations()->keys() as $alias) {
 			$assoc = $subject->association($alias);
-			$name = $assoc->target()->alias();
+			$target = $assoc->target();
+			$name = $target->alias();
+
+			if (get_class($subject) === get_class($target)) {
+				continue;
+			}
+
 			if (!isset($this->_fixtures[$name])) {
-				$this->_processModel($assoc->target());
+				$this->_processModel($target);
 			}
 			if ($assoc->type() === Association::MANY_TO_MANY) {
 				$junction = $assoc->junction();

tests/TestCase/Shell/Task/TestTaskTest.php

@@ -27,6 +27,7 @@
 use Cake\TestSuite\TestCase;
 use TestApp\Controller\PostsController;
 use TestApp\Model\Table\ArticlesTable;
+use TestApp\Model\Table\CategoryThreadsTable;
 
 /**
  * TestTaskTest class
@@ -39,8 +40,13 @@ class TestTaskTest extends TestCase {
  *
  * @var string
  */
-	public $fixtures = ['core.article', 'core.author',
-		'core.comment', 'core.articles_tag', 'core.tag'];
+	public $fixtures = [
+		'core.article',
+		'core.author',
+		'core.comment',
+		'core.articles_tag',
+		'core.tag',
+	];
 
 /**
  * setUp method
@@ -221,6 +227,20 @@ public function testFixtureArrayGenerationFromModel() {
 		$this->assertEquals($expected, $result);
 	}
 
+/**
+ * test that the generation of fixtures works correctly.
+ *
+ * @return void
+ */
+	public function testFixtureArrayGenerationIgnoreSelfAssociation() {
+		$subject = new CategoryThreadsTable();
+		$result = $this->Task->generateFixtureList($subject);
+		$expected = [
+			'app.category_thread',
+		];
+		$this->assertEquals($expected, $result);
+	}
+
 /**
  * test that the generation of fixtures works correctly.
  *