MDL-77829 core: Added environment check for mod_assignment

Decided to add an environment check before uninstalling the
mod_assignment plugin to prevent data lost.

admin/environment.xml

@@ -4109,6 +4109,11 @@
       </CUSTOM_CHECK>
       <CUSTOM_CHECK file="lib/upgradelib.php" function="check_xmlrpc_usage" level="optional">
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_mod_assignment" level="required">
+        <FEEDBACK>
+          <ON_ERROR message="modassignmentinuse" />
+        </FEEDBACK>
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
 </COMPATIBILITY_MATRIX>

lang/en/admin.php

@@ -1513,6 +1513,7 @@
 $string['xmlrpcwebserviceenabled'] = 'It has been detected that the XML-RPC Web Service protocol is enabled on your site. This feature relies on the PHP XML-RPC extension which is no longer maintained by PHP.';
 $string['yuicomboloading'] = 'YUI combo loading';
 $string['ziprequired'] = 'The Zip PHP extension is now required by Moodle, info-ZIP binaries or PclZip library are not used anymore.';
+$string['modassignmentinuse'] = 'It has been detected that your site is still using the Assignment 2.2 plugin. You may resolve this before upgrading by 1) Backing up your Assignment 2.2 activities and restoring them as new Assignment activities; or 2) Deleting the data from the assignment tables in the database.';
 
 
 $string['caching'] = 'Caching';

lib/tests/upgradelib_test.php

@@ -1526,4 +1526,27 @@ public function test_admin_dir_usage_non_standard(): void {
         $this->assertEquals('admin_dir_usage', $result->getInfo());
         $this->assertFalse($result->getStatus());
     }
+
+    /**
+     * Test the check_mod_assignment check if mod_assignment is still used.
+     *
+     * @covers ::check_mod_assignment
+     * @return void
+     */
+    public function test_check_mod_assignment_is_used(): void {
+        global $DB;
+
+        $this->resetAfterTest();
+        $result = new environment_results('custom_checks');
+
+        if ($DB->get_manager()->table_exists('assignment')) {
+            $DB->insert_record('assignment', (object)['name' => 'test_assign', 'intro' => 'test_assign_intro']);
+
+            $this->assertNotNull(check_mod_assignment($result));
+            $this->assertEquals('Assignment 2.2 is in use', $result->getInfo());
+            $this->assertFalse($result->getStatus());
+        } else {
+            $this->assertTrue($result->getStatus());
+        }
+    }
 }

lib/upgradelib.php

@@ -2778,3 +2778,22 @@ function check_xmlrpc_usage(environment_results $result): ?environment_results {
 
     return null;
 }
+
+/**
+ * Check whether the mod_assignment is currently being used.
+ *
+ * @param environment_results $result
+ * @return environment_results|null
+ */
+function check_mod_assignment(environment_results $result): ?environment_results {
+    global $DB;
+
+    // Check the number of records.
+    if ($DB->get_manager()->table_exists('assignment') && $DB->count_records('assignment') > 0) {
+        $result->setInfo('Assignment 2.2 is in use');
+        $result->setFeedbackStr('modassignmentinuse');
+        return $result;
+    }
+
+    return null;
+}