feat(mentorship): limit allowed open requests (#238)

Author: moshfeu

src/modules/mentorships/__tests__/mentorships.controller.spec.ts

@@ -125,7 +125,24 @@ describe('modules/mentorships/MentorshipsController', () => {
       ).rejects.toThrow(BadRequestException);
     });
 
+    it('should return a 400 error if the user exceeded the allowed open requests', async () => {
+      mentorshipsService.getOpenRequestsCount = jest.fn(() =>
+        Promise.resolve(5),
+      );
+
+      await expect(
+        mentorshipsController.applyForMentorship(
+          <Request>request,
+          mentorId,
+          mentorship,
+        ),
+      ).rejects.toThrow(BadRequestException);
+    });
+
     it('should return a successful response', async () => {
+      mentorshipsService.getOpenRequestsCount = jest.fn(() =>
+        Promise.resolve(3),
+      );
       const data = await mentorshipsController.applyForMentorship(
         <Request>request,
         mentorId,

src/modules/mentorships/mentorships.controller.ts

@@ -38,6 +38,8 @@ import { FindOneParams } from '../common/dto/findOneParams.dto';
 import { MentorshipUpdatePayload } from './dto/mentorshipUpdatePayload.dto';
 import { mentorshipsToDtos } from './mentorshipsToDto';
 
+const ALLOWED_OPEN_MENTORSHIPS = 5;
+
 @ApiUseTags('/mentorships')
 @Controller('mentorships')
 export class MentorshipsController {
@@ -85,6 +87,15 @@ export class MentorshipsController {
       throw new BadRequestException('A mentorship request already exists');
     }
 
+    const openMentorships = await this.mentorshipsService.getOpenRequestsCount(
+      current._id,
+    );
+    if (openMentorships >= ALLOWED_OPEN_MENTORSHIPS) {
+      throw new BadRequestException(
+        'You reached the maximum of open requests. Please wait a little longer for responses or cancel some of the requests',
+      );
+    }
+
     await this.mentorshipsService.createMentorship({
       mentor: mentor._id,
       mentee: current._id,
@@ -239,7 +250,7 @@ export class MentorshipsController {
           ? `https://coding-coach.slack.com/team/${slack.id}`
           : `mailto:${currentUser.email}`;
 
-        const openRequests = await this.mentorshipsService.getOpenRequests(
+        const openRequests = await this.mentorshipsService.getOpenRequestsCount(
           mentee._id,
         );
 

src/modules/mentorships/mentorships.service.ts

@@ -101,7 +101,7 @@ export class MentorshipsService {
    * Count open mentorship requests of a user
    * @param userId
    */
-  getOpenRequests(userId: string): Promise<number> {
+  getOpenRequestsCount(userId: string): Promise<number> {
     if (isObjectId(userId)) {
       return this.mentorshipModel
         .countDocuments({

test/api/mentorships.e2e-spec.ts

@@ -287,4 +287,47 @@ describe('Mentorships', () => {
       });
     });
   });
+
+  describe('POST /mentorships/:mentorId/apply', () => {
+    it('returns a status code of 400 if user has reached the maximum of allowed open requests', async () => {
+      const sendMentorshipRequest = (mentor, mentee) => {
+        const token = getToken(mentee);
+        const field = '1'.repeat(31);
+
+        return request(server)
+          .post(`/mentorships/${mentor._id}/apply`)
+          .set('Authorization', `Bearer ${token}`)
+          .send({
+            expectation: field,
+            message: field,
+            background: field,
+          });
+      };
+
+      const roles = [Role.MENTOR];
+      const [mentee, ...mentors] = await Promise.all([
+        createUser(),
+        createUser({ roles }),
+        createUser({ roles }),
+        createUser({ roles }),
+        createUser({ roles }),
+        createUser({ roles }),
+        createUser({ roles }),
+      ]);
+
+      const [lastMentor] = mentors.splice(-1);
+      await Promise.all(
+        mentors.map((mentor) =>
+          sendMentorshipRequest(mentor, mentee).expect({ success: true }),
+        ),
+      );
+      const {
+        body: { message },
+      } = await sendMentorshipRequest(lastMentor, mentee).expect(400);
+
+      expect(message).toBe(
+        'You reached the maximum of open requests. Please wait a little longer for responses or cancel some of the requests',
+      );
+    });
+  });
 });