feat: set limit to posts per day

backend/.env

@@ -5,4 +5,5 @@ FB_PARAMS_CLIENT_ID=107235746829504040378
 FB_PARAMS_AUTH_URI=https://accounts.google.com/o/oauth2/auth
 FB_PARAMS_TOKEN_URI=https://oauth2.googleapis.com/token
 FB_PARAMS_AUTH_PROVIDER_X509_CERT_URL=https://www.googleapis.com/oauth2/v1/certs
-FB_PARAMS_CLIENT_C509_CERT_URL=https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-j8wbf%40wsne-28b5b.iam.gserviceaccount.com
+FB_PARAMS_CLIENT_C509_CERT_URL=https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-j8wbf%40wsne-28b5b.iam.gserviceaccount.com
+MAX_NUMBER_POSTS_PER_DAY=10

backend/src/posts/service.spec.ts

@@ -0,0 +1,83 @@
+import { CollectionReference } from '@google-cloud/firestore';
+import { PostDocument } from './document';
+import { Service } from './service';
+
+describe('Service', () => {
+  let old_env;
+  let service;
+  beforeEach(() => {
+    const postsCollection: CollectionReference<PostDocument> = null;
+    service = new Service(postsCollection);
+  });
+  describe('create', () => {
+    let postsCollectionMock;
+    beforeEach(() => {
+      old_env = process.env;
+      process.env = { MAX_NUMBER_POSTS_PER_DAY: '5' };
+      postsCollectionMock = {
+        where: jest.fn().mockReturnThis(),
+        get: jest.fn().mockResolvedValue({
+          size: 0,
+          id: '1',
+          data: jest.fn().mockReturnValue({
+            message: 'test',
+            date: 100000,
+            userId: '1234',
+          }),
+        }),
+        doc: jest.fn().mockReturnThis(),
+        set: jest.fn().mockResolvedValueOnce({}),
+      };
+      service.postsCollection = postsCollectionMock;
+    });
+    afterEach(() => {
+      process.env = old_env;
+      jest.restoreAllMocks();
+    });
+    it('should return a new post', async () => {
+      const post = {
+        message: 'test',
+      };
+
+      const result = await service.create(post, {
+        user_id: '1234',
+        name: 'Test',
+      });
+
+      expect(result).toEqual({
+        date: 100000,
+        id: '1',
+        message: 'test',
+        userId: '1234',
+        userName: 'Test',
+      });
+    });
+    describe('when user has reached max number of posts per day', () => {
+      let postsCollectionMock;
+      beforeEach(() => {
+        // old_env = process.env;
+        // process.env = { MAX_NUMBER_POSTS_PER_DAY: '5' };
+        postsCollectionMock = {
+          where: jest.fn().mockReturnThis(),
+          get: jest.fn().mockResolvedValueOnce({ size: 5 }),
+        };
+        service.postsCollection = postsCollectionMock;
+      });
+      afterEach(() => {
+        // process.env = old_env;
+        jest.restoreAllMocks();
+      });
+      it('throws an error', async () => {
+        const user = {
+          user_id: '1',
+          email: 'test@test.com',
+        };
+        const message = 'new message';
+
+        await expect(service.create({ message }, user)).rejects.toThrow(
+          'You have reached the limit of 5 posts per day',
+        );
+      });
+    });
+  });
+});

backend/src/posts/service.ts

@@ -54,6 +54,24 @@ export class Service {
     const { user_id: userId, name: userName } = user;
     const t = dayjs(new Date()).valueOf();
 
+    const numberPostsCreatedToday = await this.postsCollection
+      .where('date', '>=', t - 86400000)
+      .where('userId', '==', userId)
+      .get()
+      .then((snapshot) => snapshot.size);
+
+    const maxNumberPostsPerDay = parseInt(
+      process.env.MAX_NUMBER_POSTS_PER_DAY,
+      10,
+    );
+    if (numberPostsCreatedToday >= maxNumberPostsPerDay) {
+      throw new Error(
+        'You have reached the limit of ' +
+          maxNumberPostsPerDay +
+          ' posts per day',
+      );
+    }
+
     const docRef = this.postsCollection.doc(t.toString());
     await docRef.set({
       message,