feature(database-connection): Add tests for timetracking and add fallback value to max season for fetching stats

backend/src/database/database.service.spec.ts

@@ -1,13 +1,25 @@
 import { Test, TestingModule } from '@nestjs/testing';
+import { seasons } from '@prisma/client';
 import { DatabaseService } from './database.service';
+import { mockReset, MockProxy, mockDeep } from 'jest-mock-extended';
+import { SeasonInfo } from '../models/aliases';
+import { PrismaService } from '../prisma/prisma.service';
+import { TimeTrackerPredicate } from './timetracking.predicate';
+import { mocked } from 'ts-jest';
 
 describe('DatabaseService', () => {
   let service: DatabaseService;
+  const mockedPrismaService: MockProxy<PrismaService> = mockDeep<PrismaService>();
 
   beforeEach(async () => {
+    mockReset(mockedPrismaService);
+
     const module: TestingModule = await Test.createTestingModule({
-      providers: [DatabaseService],
-    }).compile();
+      providers: [DatabaseService, PrismaService, TimeTrackerPredicate],
+    })
+    .overrideProvider(PrismaService)
+    .useValue(mockedPrismaService)
+    .compile();
 
     service = module.get<DatabaseService>(DatabaseService);
   });
@@ -15,4 +27,43 @@ describe('DatabaseService', () => {
   it('should be defined', () => {
     expect(service).toBeDefined();
   });
+
+  // TODO This will be skipped as Prisma__#client can barely be mocked.
+  // it('fetch season info with season ID given', async () => {
+  //   const seasonIdToBeTested = 1;
+  //   const mockedValue: seasons = {
+  //     season_id: 2,
+  //     start_date: new Date('1995-12-17T03:24:00'),
+  //     end_date: null
+  //   };
+  //   const mockedMaxSeasonId = {
+  //     max: {
+  //       season_id: 2
+  //     }
+  //   };
+  //
+  //   mockedPrismaService.seasons.findUnique.calledWith({
+  //     where: {
+  //       season_id: Number(seasonIdToBeTested)
+  //     }
+  //   }).mockImplementation((subset) => {
+  //     return new Promise(resolve => resolve(mockedValue));
+  //   });
+  //
+  //   mockedPrismaService.seasons.aggregate.calledWith({
+  //     max: {
+  //       season_id: true
+  //     }
+  //   }).mockImplementation(() => Promise.resolve(mockedMaxSeasonId));
+  //
+  //   const expected: SeasonInfo = {
+  //     season_id: 2,
+  //     maxSeasonId: 2,
+  //     start_date: new Date('1995-12-17T03:24:00'),
+  //     end_date: null
+  //   }
+  //   const actual = service.fetchSeasonInfos();
+  //
+  //   await expect(actual).resolves.toEqual(expected);
+  // });
 });