update user progress for topics

functions/src/progress/onWrite/__tests__/updateTopic.spec.ts

@@ -0,0 +1,31 @@
+import functions from 'firebase-functions-test';
+import * as admin from 'firebase-admin';
+
+const testEnv = functions();
+const db = admin.firestore();
+
+import { onWriteProgressUpdateTopic } from '../updateTopic';
+
+beforeAll(() => {
+  const chapterData = { topics: ['topicId'] };
+  spyOn(db.doc(''), 'set').and.returnValue('updated');
+  spyOn(db.doc(''), 'get').and.returnValue({ data: () => chapterData });
+});
+
+test('update the lessons count for a topic', async (done) => {
+  const data = { examples: new Array(2), lessons: new Array(4) };
+  const change = {
+    before: { data: () => undefined },
+    after: { data: () => data },
+  };
+  const params = { chapterId: '123', userId: 'user' };
+  const wrapped = testEnv.wrap(onWriteProgressUpdateTopic);
+  const req = await wrapped(change, { params });
+  const payload = { 123: { examples: 2, lessons: 4, posts: 6 } };
+
+  expect(req).toBe('updated');
+  expect(db.doc).toHaveBeenCalledWith('topics/topicId/progress/user');
+  expect(db.doc).toHaveBeenCalledWith('chapters/123');
+  expect(db.doc('').set).toHaveBeenCalledWith(payload, { merge: true });
+  done();
+});

functions/src/progress/onWrite/index.ts

@@ -1 +1,2 @@
 export * from './earnXp';
+export * from './updateTopic';

functions/src/progress/onWrite/updateTopic.ts

@@ -0,0 +1,35 @@
+import * as functions from 'firebase-functions';
+import * as admin from 'firebase-admin';
+import { Chapter, ChapterProgress, TopicProgress } from '@zoonk/models';
+
+const db = admin.firestore();
+
+/**
+ * When a chapter progress is updated, we also need to update
+ * its topic progress. This makes easier to analyze a topic
+ * progress in the frontend (avoiding the need to have multiple
+ * calls - one for each chapter - to get the topic progress).
+ */
+export const onWriteProgressUpdateTopic = functions.firestore
+  .document('chapters/{chapterId}/progress/{userId}')
+  .onWrite(async (change, context) => {
+    const { chapterId, userId } = context.params;
+    const after = change.after.data() as ChapterProgress.Response | undefined;
+    const chapter = await db.doc(`chapters/${chapterId}`).get();
+    const chapterData = chapter.data() as Chapter.Response;
+    const topicId = chapterData.topics[0];
+    const examples = after?.examples?.length || 0;
+    const lessons = after?.lessons?.length || 0;
+
+    const payload: TopicProgress = {
+      [chapterId]: {
+        examples,
+        lessons,
+        posts: examples + lessons,
+      },
+    };
+
+    return db
+      .doc(`topics/${topicId}/progress/${userId}`)
+      .set(payload, { merge: true });
+  });

src/models/progress.ts

@@ -13,3 +13,7 @@ export namespace ChapterProgress {
     lessons?: string[];
   }
 }
+
+export interface TopicProgress {
+  [chapterId: string]: { examples: number; lessons: number; posts: number };
+}