MDL-70815 core_completion: completion_info::get_grade_completion()

Move the current logic for determining the completion status for the
"Student must receive grade" completion rule to a function so it cann
be reused.
Unit test included.

lib/completionlib.php

@@ -643,7 +643,7 @@ class completion_info {
      * @return mixed
      */
     public function internal_get_state($cm, $userid, $current) {
-        global $USER, $DB, $CFG;
+        global $USER, $DB;
 
         // Get user ID
         if (!$userid) {
@@ -657,49 +657,37 @@ class completion_info {
             return COMPLETION_INCOMPLETE;
         }
 
-        // Modname hopefully is provided in $cm but just in case it isn't, let's grab it
+        if ($cm instanceof stdClass) {
+            // Modname hopefully is provided in $cm but just in case it isn't, let's grab it.
             if (!isset($cm->modname)) {
                 $cm->modname = $DB->get_field('modules', 'name', array('id' => $cm->module));
             }
+            // Some functions call this method and pass $cm as an object with ID only. Make sure course is set as well.
+            if (!isset($cm->course)) {
+                $cm->course = $this->course_id;
+            }
+        }
+        // Make sure we're using a cm_info object.
+        $cminfo = cm_info::create($cm, $userid);
 
         $newstate = COMPLETION_COMPLETE;
 
         // Check grade
-        if (!is_null($cm->completiongradeitemnumber)) {
+        if (!is_null($cminfo->completiongradeitemnumber)) {
-            require_once($CFG->libdir.'/gradelib.php');
+            $newstate = $this->get_grade_completion($cminfo, $userid);
-            $item = grade_item::fetch(array('courseid'=>$cm->course, 'itemtype'=>'mod',
-                'itemmodule'=>$cm->modname, 'iteminstance'=>$cm->instance,
-                'itemnumber'=>$cm->completiongradeitemnumber));
-            if ($item) {
-                // Fetch 'grades' (will be one or none)
-                $grades = grade_grade::fetch_users_grades($item, array($userid), false);
-                if (empty($grades)) {
-                    // No grade for user
-                    return COMPLETION_INCOMPLETE;
-                }
-                if (count($grades) > 1) {
-                    $this->internal_systemerror("Unexpected result: multiple grades for
-                        item '{$item->id}', user '{$userid}'");
-                }
-                $newstate = self::internal_get_grade_state($item, reset($grades));
             if ($newstate == COMPLETION_INCOMPLETE) {
                 return COMPLETION_INCOMPLETE;
             }
-
-            } else {
-                $this->internal_systemerror("Cannot find grade item for '{$cm->modname}'
-                    cm '{$cm->id}' matching number '{$cm->completiongradeitemnumber}'");
-            }
         }
 
-        if (plugin_supports('mod', $cm->modname, FEATURE_COMPLETION_HAS_RULES)) {
+        if (plugin_supports('mod', $cminfo->modname, FEATURE_COMPLETION_HAS_RULES)) {
-            $function = $cm->modname.'_get_completion_state';
+            $function = $cminfo->modname . '_get_completion_state';
             if (!function_exists($function)) {
-                $this->internal_systemerror("Module {$cm->modname} claims to support
+                $this->internal_systemerror("Module {$cminfo->modname} claims to support
                     FEATURE_COMPLETION_HAS_RULES but does not have required
                     {$cm->modname}_get_completion_state function");
             }
-            if (!$function($this->course, $cm, $userid, COMPLETION_AND)) {
+            if (!$function($this->course, $cminfo, $userid, COMPLETION_AND)) {
                 return COMPLETION_INCOMPLETE;
             }
         }
@@ -708,6 +696,44 @@ class completion_info {
 
     }
 
+    /**
+     * Fetches the completion state for an activity completion's require grade completion requirement.
+     *
+     * @param cm_info $cm The course module information.
+     * @param int $userid The user ID.
+     * @return int The completion state.
+     */
+    public function get_grade_completion(cm_info $cm, int $userid): int {
+        global $CFG;
+
+        require_once($CFG->libdir . '/gradelib.php');
+        $item = grade_item::fetch([
+            'courseid' => $cm->course,
+            'itemtype' => 'mod',
+            'itemmodule' => $cm->modname,
+            'iteminstance' => $cm->instance,
+            'itemnumber' => $cm->completiongradeitemnumber
+        ]);
+        if ($item) {
+            // Fetch 'grades' (will be one or none).
+            $grades = grade_grade::fetch_users_grades($item, [$userid], false);
+            if (empty($grades)) {
+                // No grade for user.
+                return COMPLETION_INCOMPLETE;
+            }
+            if (count($grades) > 1) {
+                $this->internal_systemerror("Unexpected result: multiple grades for
+                        item '{$item->id}', user '{$userid}'");
+            }
+            return self::internal_get_grade_state($item, reset($grades));
+        } else {
+            $this->internal_systemerror("Cannot find grade item for '{$cm->modname}'
+                    cm '{$cm->id}' matching number '{$cm->completiongradeitemnumber}'");
+        }
+
+        return COMPLETION_INCOMPLETE;
+    }
+
     /**
      * Marks a module as viewed.
      *

lib/tests/completionlib_test.php

@@ -1143,6 +1143,60 @@ class core_completionlib_testcase extends advanced_testcase {
         $this->assertTrue(completion_can_view_data($student->id, $this->course->id));
         $this->assertFalse(completion_can_view_data($this->user->id, $this->course->id));
     }
+
+    /**
+     * Data provider for test_get_grade_completion().
+     *
+     * @return array[]
+     */
+    public function get_grade_completion_provider() {
+        return [
+            'Grade not required' => [false, false, null, moodle_exception::class, null],
+            'Grade required, but has no grade yet' => [true, false, null, null, COMPLETION_INCOMPLETE],
+            'Grade required, grade received' => [true, true, null, null, COMPLETION_COMPLETE],
+            'Grade required, passing grade received' => [true, true, 70, null, COMPLETION_COMPLETE_PASS],
+            'Grade required, failing grade received' => [true, true, 80, null, COMPLETION_COMPLETE_FAIL],
+        ];
+    }
+
+    /**
+     * Test for \completion_info::get_grade_completion().
+     *
+     * @dataProvider get_grade_completion_provider
+     * @param bool $completionusegrade Whether the test activity has grade completion requirement.
+     * @param bool $hasgrade Whether to set grade for the user in this activity.
+     * @param int|null $passinggrade Passing grade to set for the test activity.
+     * @param string|null $expectedexception Expected exception.
+     * @param int|null $expectedresult The expected completion status.
+     */
+    public function test_get_grade_completion(bool $completionusegrade, bool $hasgrade, ?int $passinggrade, ?string $expectedexception,
+            ?int $expectedresult) {
+        $this->setup_data();
+
+        /** @var \mod_assign_generator $assigngenerator */
+        $assigngenerator = $this->getDataGenerator()->get_plugin_generator('mod_assign');
+        $assign = $assigngenerator->create_instance([
+            'course' => $this->course->id,
+            'completion' => COMPLETION_ENABLED,
+            'completionusegrade' => $completionusegrade,
+            'gradepass' => $passinggrade,
+        ]);
+
+        $cm = cm_info::create(get_coursemodule_from_instance('assign', $assign->id));
+        if ($completionusegrade && $hasgrade) {
+            $assigninstance = new assign($cm->context, $cm, $this->course);
+            $grade = $assigninstance->get_user_grade($this->user->id, true);
+            $grade->grade = 75;
+            $assigninstance->update_grade($grade);
+        }
+
+        $completioninfo = new completion_info($this->course);
+        if ($expectedexception) {
+            $this->expectException($expectedexception);
+        }
+        $gradecompletion = $completioninfo->get_grade_completion($cm, $this->user->id);
+        $this->assertEquals($expectedresult, $gradecompletion);
+    }
 }
 
 class core_completionlib_fake_recordset implements Iterator {