diff --git a/src/users/users.service.spec.ts b/src/users/users.service.spec.ts
index 4bff57b39..db93576fa 100644
--- a/src/users/users.service.spec.ts
+++ b/src/users/users.service.spec.ts
@@ -9,11 +9,14 @@ import { getRepositoryToken } from '@nestjs/typeorm';
 import { LoggerModule } from '../logger/logger.module';
 import { User } from './user.entity';
 import { UsersService } from './users.service';
+import { Repository } from 'typeorm';
+import { AlreadyInDBError, NotInDBError } from '../errors/errors';
 import { ConfigModule } from '@nestjs/config';
 import appConfigMock from '../config/mock/app.config.mock';
 
 describe('UsersService', () => {
   let service: UsersService;
+  let userRepo: Repository<User>;
 
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
@@ -21,7 +24,7 @@ describe('UsersService', () => {
         UsersService,
         {
           provide: getRepositoryToken(User),
-          useValue: {},
+          useClass: Repository,
         },
       ],
       imports: [
@@ -31,15 +34,124 @@ describe('UsersService', () => {
         }),
         LoggerModule,
       ],
-    })
-      .overrideProvider(getRepositoryToken(User))
-      .useValue({})
-      .compile();
+    }).compile();
 
     service = module.get<UsersService>(UsersService);
+    userRepo = module.get<Repository<User>>(getRepositoryToken(User));
   });
 
   it('should be defined', () => {
     expect(service).toBeDefined();
   });
+
+  describe('createUser', () => {
+    const username = 'hardcoded';
+    const displayname = 'Testy';
+    beforeEach(() => {
+      jest
+        .spyOn(userRepo, 'save')
+        .mockImplementationOnce(async (user: User): Promise<User> => user);
+    });
+    it('works', async () => {
+      const user = await service.createUser(username, displayname);
+      expect(user.userName).toEqual(username);
+      expect(user.displayName).toEqual(displayname);
+    });
+    it('fails if username is already taken', async () => {
+      jest.spyOn(userRepo, 'save').mockImplementationOnce(() => {
+        throw new Error();
+      });
+      // create first user with username
+      await service.createUser(username, displayname);
+      // attempt to create second user with username
+      await expect(service.createUser(username, displayname)).rejects.toThrow(
+        AlreadyInDBError,
+      );
+    });
+  });
+
+  describe('deleteUser', () => {
+    it('works', async () => {
+      const username = 'hardcoded';
+      const displayname = 'Testy';
+      const newUser = User.create(username, displayname) as User;
+      jest.spyOn(userRepo, 'remove').mockImplementationOnce(
+        // eslint-disable-next-line @typescript-eslint/require-await
+        async (user: User): Promise<User> => {
+          expect(user).toEqual(newUser);
+          return user;
+        },
+      );
+      await service.deleteUser(newUser);
+    });
+  });
+
+  describe('changedDisplayName', () => {
+    it('works', async () => {
+      const username = 'hardcoded';
+      const displayname = 'Testy';
+      const user = User.create(username, displayname) as User;
+      const newDisplayName = 'Testy2';
+      jest.spyOn(userRepo, 'save').mockImplementationOnce(
+        // eslint-disable-next-line @typescript-eslint/require-await
+        async (user: User): Promise<User> => {
+          expect(user.displayName).toEqual(newDisplayName);
+          return user;
+        },
+      );
+      await service.changeDisplayName(user, newDisplayName);
+    });
+  });
+
+  describe('getUserByUsername', () => {
+    const username = 'hardcoded';
+    const displayname = 'Testy';
+    const user = User.create(username, displayname) as User;
+    it('works', async () => {
+      jest.spyOn(userRepo, 'findOne').mockResolvedValueOnce(user);
+      const getUser = await service.getUserByUsername(username);
+      expect(getUser.userName).toEqual(username);
+      expect(getUser.displayName).toEqual(displayname);
+    });
+    it('fails when user does not exits', async () => {
+      jest.spyOn(userRepo, 'findOne').mockResolvedValueOnce(undefined);
+      await expect(service.getUserByUsername(username)).rejects.toThrow(
+        NotInDBError,
+      );
+    });
+  });
+
+  describe('getPhotoUrl', () => {
+    const username = 'hardcoded';
+    const displayname = 'Testy';
+    const user = User.create(username, displayname) as User;
+    it('works if a user has a photoUrl', () => {
+      const photo = 'testPhotoUrl';
+      user.photo = photo;
+      const photoUrl = service.getPhotoUrl(user);
+      expect(photoUrl).toEqual(photo);
+    });
+    it('works if a user no photoUrl', () => {
+      user.photo = undefined;
+      const photoUrl = service.getPhotoUrl(user);
+      expect(photoUrl).toEqual('');
+    });
+  });
+
+  describe('toUserDto', () => {
+    const username = 'hardcoded';
+    const displayname = 'Testy';
+    const user = User.create(username, displayname) as User;
+    it('works if a user is provided', () => {
+      const userDto = service.toUserDto(user);
+      expect(userDto.userName).toEqual(username);
+      expect(userDto.displayName).toEqual(displayname);
+      expect(userDto.photo).toEqual('');
+      expect(userDto.email).toEqual('');
+    });
+    it('fails if no user is provided', () => {
+      expect(service.toUserDto(null)).toBeNull();
+      expect(service.toUserDto(undefined)).toBeNull();
+    });
+  });
 });