MDL-62370 core_privacy: Directory-less subsystems are compliant

lang/en/privacy.php

@@ -23,3 +23,4 @@
  */
 
 $string['privacy:metadata'] = 'The privacy subsystem does not store any data of its own and is designed to act as a channel between components and the interface used to describe, export, and remove their data.';
+$string['privacy:subsystem:empty'] = 'This subsystem does not store any data.';

privacy/classes/manager.php

@@ -123,11 +123,17 @@ class manager {
         if ($this->component_implements($component, \core_privacy\local\metadata\null_provider::class)) {
             return true;
         }
+
+        if (static::is_empty_subsystem($component)) {
+            return true;
+        }
+
         // Components which store user data must implement the local\metadata\provider and the local\request\data_provider.
         if ($this->component_implements($component, \core_privacy\local\metadata\provider::class) &&
             $this->component_implements($component, \core_privacy\local\request\data_provider::class)) {
             return true;
         }
+
         return false;
     }
 
@@ -145,6 +151,23 @@ class manager {
         }
     }
 
+    /**
+     * Return whether this is an 'empty' subsystem - that is, a subsystem without a directory.
+     *
+     * @param  string $component Frankenstyle component name.
+     * @return string The key to retrieve the language string for the null provider reason.
+     */
+    public static function is_empty_subsystem($component) {
+        if (strpos($component, 'core_') === 0) {
+            if (null === \core_component::get_subsystem_directory(substr($component, 5))) {
+                // This is a subsystem without a directory.
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /**
      * Get the privacy metadata for all components.
      *

privacy/tests/manager_test.php

@@ -129,6 +129,38 @@ class privacy_manager_testcase extends advanced_testcase {
         $this->assertFalse($mockman->component_is_compliant('tool_thisisnotarealtool123'));
     }
 
+    /**
+     * Provider for component_is_compliant tests.
+     *
+     * @return  array
+     */
+    public function component_is_compliant_provider() {
+        return [
+            'An empty subsystem' => [
+                'core_countries',
+                true,
+            ],
+            'A real subsystem' => [
+                'core_privacy',
+                true,
+            ],
+        ];
+    }
+
+    /**
+     * Test verifying the output of component_is_compliant with specified
+     * components.
+     *
+     * @dataProvider    component_is_compliant_provider
+     * @param   string  $component
+     * @param   boolean $expected
+     */
+    public function test_component_is_compliant_examples($component, $expected) {
+        $manager = new \core_privacy\manager();
+
+        $this->assertEquals($expected, $manager->component_is_compliant($component));
+    }
+
     /**
      *  Test verifying only approved contextlists can be used with the export_user_data method.
      */
@@ -227,4 +259,45 @@ class privacy_manager_testcase extends advanced_testcase {
     public function test_component_class_callback() {
         \core_privacy\manager::component_class_callback('foo_bar', 'unusable', 'foo', ['bar']);
     }
+
+    /**
+     * Test the manager::is_empty_subsystem function.
+     *
+     * @dataProvider is_empty_subsystem_provider
+     * @param   string  $component
+     * @param   bool    $expected
+     */
+    public function test_is_empty_subsystem($component, $expected) {
+        $this->assertEquals($expected, \core_privacy\manager::is_empty_subsystem($component));
+    }
+
+    /**
+     * Test cases for the is_empty_subsystem function.
+     *
+     * @return array
+     */
+    public function is_empty_subsystem_provider() {
+        return [
+            'A subsystem which has no directory' => [
+                'core_langconfig',
+                true,
+            ],
+            'A subsystem with a directory' => [
+                'core_portfolio',
+                false,
+            ],
+            'A plugin' => [
+                'mod_forum',
+                false,
+            ],
+            'A plugintype' => [
+                'mod',
+                false,
+            ],
+            'An unprefixed subsystem with no directory' => [
+                'langconfig',
+                false,
+            ],
+        ];
+    }
 }