feat(api): user authentication

src/users/users.service.spec.ts

@@ -0,0 +1,18 @@
+import { Test, TestingModule } from "@nestjs/testing";
+import { UsersService } from "./users.service";
+
+describe("UsersService", () => {
+  let service: UsersService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [UsersService]
+    }).compile();
+
+    service = module.get<UsersService>(UsersService);
+  });
+
+  it("should be defined", () => {
+    expect(service).toBeDefined();
+  });
+});