From 3ce936fe6d6c6807c0c43480323160e91904c35c Mon Sep 17 00:00:00 2001
From: Noel De Martin <noel@moodle.com>
Date: Tue, 19 Oct 2021 12:31:30 +0200
Subject: [PATCH] MDL-72846 testing: Add default block generators

---
 lib/testing/generator/data_generator.php      | 38 ++++++++++--
 .../generator/default_block_generator.php     | 59 +++++++++++++++++++
 lib/testing/generator/lib.php                 |  2 +-
 lib/testing/tests/generator_test.php          |  5 ++
 4 files changed, 97 insertions(+), 7 deletions(-)
 create mode 100644 lib/testing/generator/default_block_generator.php

diff --git a/lib/testing/generator/data_generator.php b/lib/testing/generator/data_generator.php
index 1eae6af1926..7948bd15873 100644
--- a/lib/testing/generator/data_generator.php
+++ b/lib/testing/generator/data_generator.php
@@ -121,19 +121,20 @@ EOD;
         $dir = core_component::get_component_directory($component);
         $lib = $dir . '/tests/generator/lib.php';
         if (!$dir || !is_readable($lib)) {
-            throw new coding_exception("Component {$component} does not support " .
-                    "generators yet. Missing tests/generator/lib.php.");
+            $this->generators[$component] = $this->get_default_plugin_generator($component);
+
+            return $this->generators[$component];
         }
 
         include_once($lib);
         $classname = $component . '_generator';
 
-        if (!class_exists($classname)) {
-            throw new coding_exception("Component {$component} does not support " .
-                    "data generators yet. Class {$classname} not found.");
+        if (class_exists($classname)) {
+            $this->generators[$component] = new $classname($this);
+        } else {
+            $this->generators[$component] = $this->get_default_plugin_generator($component, $classname);
         }
 
-        $this->generators[$component] = new $classname($this);
         return $this->generators[$component];
     }
 
@@ -1347,4 +1348,29 @@ EOD;
 
         return $DB->get_record('user_lastaccess', ['id' => $recordid], '*', MUST_EXIST);
     }
+
+    /**
+     * Gets a default generator for a given component.
+     *
+     * @param string $component The component name, e.g. 'mod_forum' or 'core_question'.
+     * @param string $classname The name of the class missing from the generators file.
+     * @return component_generator_base The generator.
+     */
+    protected function get_default_plugin_generator(string $component, ?string $classname = null) {
+        [$type, $plugin] = core_component::normalize_component($component);
+
+        switch ($type) {
+            case 'block':
+                return new default_block_generator($this, $plugin);
+        }
+
+        if (is_null($classname)) {
+            throw new coding_exception("Component {$component} does not support " .
+                "generators yet. Missing tests/generator/lib.php.");
+        }
+
+        throw new coding_exception("Component {$component} does not support " .
+            "data generators yet. Class {$classname} not found.");
+    }
+
 }
diff --git a/lib/testing/generator/default_block_generator.php b/lib/testing/generator/default_block_generator.php
new file mode 100644
index 00000000000..b86eb1a4413
--- /dev/null
+++ b/lib/testing/generator/default_block_generator.php
@@ -0,0 +1,59 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Default block generator class.
+ *
+ * @package    core
+ * @category   test
+ * @copyright  2021 Moodle Pty Ltd. (http://moodle.com)
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+/**
+ * Default block generator class to be used when a specific one is not supported.
+ *
+ * @package    core
+ * @category   test
+ * @copyright  2021 Moodle Pty Ltd. (http://moodle.com)
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class default_block_generator extends testing_block_generator {
+
+    /**
+     * @var string
+     */
+    private $blockname;
+
+    /**
+     * Constructor.
+     * @param testing_data_generator $datagenerator
+     * @param string $blockname
+     */
+    public function __construct(testing_data_generator $datagenerator, string $blockname) {
+        parent::__construct($datagenerator);
+
+        $this->blockname = $blockname;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function get_blockname() {
+        return $this->blockname;
+    }
+
+}
diff --git a/lib/testing/generator/lib.php b/lib/testing/generator/lib.php
index 7e2b19099ce..620d6008eba 100644
--- a/lib/testing/generator/lib.php
+++ b/lib/testing/generator/lib.php
@@ -29,5 +29,5 @@ require_once(__DIR__.'/data_generator.php');
 require_once(__DIR__.'/component_generator_base.php');
 require_once(__DIR__.'/module_generator.php');
 require_once(__DIR__.'/block_generator.php');
+require_once(__DIR__.'/default_block_generator.php');
 require_once(__DIR__.'/repository_generator.php');
-
diff --git a/lib/testing/tests/generator_test.php b/lib/testing/tests/generator_test.php
index e1b2cfa72ae..a48e4c6cd90 100644
--- a/lib/testing/tests/generator_test.php
+++ b/lib/testing/tests/generator_test.php
@@ -47,6 +47,11 @@ class core_test_generator_testcase extends advanced_testcase {
         $this->assertInstanceOf('mod_quiz_generator', $generator);
     }
 
+    public function test_get_default_generator() {
+        $generator = $this->getDataGenerator()->get_plugin_generator('block_somethingthatdoesnotexist');
+        $this->assertInstanceOf('default_block_generator', $generator);
+    }
+
     /**
      * Test plugin generator, with no component directory.
      */