MDL-73339 blog_menu: Add block only if main feature is enabled

The Blog menu block should be added only if the blogs advanced
feature is enabled.

blocks/blog_menu/block_blog_menu.php

@@ -123,4 +123,16 @@ class block_blog_menu extends block_base {
     public function get_aria_role() {
         return 'navigation';
     }
+
+    /**
+     * This block shouldn't be added to a page if the blogs advanced feature is disabled.
+     *
+     * @param moodle_page $page
+     * @return bool
+     */
+    public function can_block_be_added(moodle_page $page): bool {
+        global $CFG;
+
+        return $CFG->enableblogs;
+    }
 }

blocks/blog_menu/tests/behat/block_blog_menu.feature

@@ -16,13 +16,12 @@ Feature: Enable Block blog menu in a course
       | teacher1 | C1 | editingteacher |
 
   Scenario: Add the block to a the course when blogs are disabled
-    Given I log in as "admin"
-    And the following config values are set as admin:
-      | enableblogs | 0 |
-    And I log out
-    And I log in as "teacher1"
+    Given I log in as "teacher1"
     And I am on "Course 1" course homepage with editing mode on
     When I add the "Blog menu" block
+    And the following config values are set as admin:
+      | enableblogs | 0 |
+    And I reload the page
     Then I should see "Blogging is disabled!" in the "Blog menu" "block"
 
   Scenario: Add the block to a the course when blog associations are disabled

blocks/blog_menu/tests/blog_menu_test.php

@@ -0,0 +1,63 @@
+<?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/>.
+
+namespace block_blog_menu\tests;
+
+use advanced_testcase;
+use block_blog_menu;
+use context_course;
+
+/**
+ * PHPUnit block_blog_menu tests
+ *
+ * @package    block_blog_menu
+ * @category   test
+ * @copyright  2021 Sara Arjona ([email protected])
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @coversDefaultClass \block_blog_menu
+ */
+class blog_menu_test extends advanced_testcase {
+    public static function setUpBeforeClass(): void {
+        require_once(__DIR__ . '/../../moodleblock.class.php');
+        require_once(__DIR__ . '/../block_blog_menu.php');
+    }
+
+    /**
+     * Test the behaviour of can_block_be_added() method.
+     *
+     * @covers ::can_block_be_added
+     */
+    public function test_can_block_be_added(): void {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        // Create a course and prepare the page where the block will be added.
+        $course = $this->getDataGenerator()->create_course();
+        $page = new \moodle_page();
+        $page->set_context(context_course::instance($course->id));
+        $page->set_pagelayout('course');
+
+        $block = new block_blog_menu();
+
+        // If blogs advanced feature is enabled, the method should return true.
+        set_config('enableblogs', true);
+        $this->assertTrue($block->can_block_be_added($page));
+
+        // However, if the blogs advanced feature is disabled, the method should return false.
+        set_config('enableblogs', false);
+        $this->assertFalse($block->can_block_be_added($page));
+    }
+}