diff --git a/backend/jest.config.js b/backend/jest.config.js
index 14fdd5e..76c1b57 100644
--- a/backend/jest.config.js
+++ b/backend/jest.config.js
@@ -8,7 +8,7 @@ module.exports = {
   // automock: false,
 
   // Stop running tests after `n` failures
-  // bail: 0,
+  bail: 1,
 
   // The directory where Jest should store its cached dependency information
   // cacheDirectory: "/tmp/jest_rs",
diff --git a/backend/src/__tests__/unit/CreateUserService.spec.ts b/backend/src/__tests__/unit/CreateUserService.spec.ts
deleted file mode 100644
index bb9b858..0000000
--- a/backend/src/__tests__/unit/CreateUserService.spec.ts
+++ /dev/null
@@ -1,41 +0,0 @@
-import { disconnect, truncate } from "../utils/database";
-// import User from "../../models/User";
-// import app from "../../app";
-import CreateUserService from "../../services/UserServices/CreateUserService";
-import AppError from "../../errors/AppError";
-
-describe("User", () => {
-  beforeEach(async () => {
-    await truncate();
-  });
-
-  afterAll(async () => {
-    await disconnect();
-  });
-
-  it("should be able to create a new user", async () => {
-    const user = await CreateUserService({
-      name: "dasdas",
-      email: "tesssst@test.com",
-      password: "passwo22221131rd"
-    });
-
-    expect(user).toHaveProperty("id");
-  });
-
-  it("should not be able to create a user with duplicated email", async () => {
-    await CreateUserService({
-      name: "dasdas",
-      email: "tesssst@test.com",
-      password: "passwo22221131rd"
-    });
-
-    expect(
-      CreateUserService({
-        name: "dasdas",
-        email: "tesssst@test.com",
-        password: "passwo22221131rd"
-      })
-    ).rejects.toBeInstanceOf(AppError);
-  });
-});
diff --git a/backend/src/__tests__/unit/User/AuthUserService.spec.ts b/backend/src/__tests__/unit/User/AuthUserService.spec.ts
new file mode 100644
index 0000000..180af23
--- /dev/null
+++ b/backend/src/__tests__/unit/User/AuthUserService.spec.ts
@@ -0,0 +1,66 @@
+import faker from "faker";
+import AppError from "../../../errors/AppError";
+import AuthUserService from "../../../services/UserServices/AuthUserSerice";
+import CreateUserService from "../../../services/UserServices/CreateUserService";
+import { disconnect, truncate } from "../../utils/database";
+
+describe("Auth", () => {
+  beforeEach(async () => {
+    await truncate();
+  });
+
+  afterEach(async () => {
+    await truncate();
+  });
+
+  afterAll(async () => {
+    await disconnect();
+  });
+
+  it("should be able to login with an existing user", async () => {
+    await CreateUserService({
+      name: faker.name.findName(),
+      email: "mail@test.com",
+      password: "hardpassword"
+    });
+
+    const response = await AuthUserService({
+      email: "mail@test.com",
+      password: "hardpassword"
+    });
+
+    expect(response).toHaveProperty("token");
+  });
+
+  it("should not be able to login with not registered email", async () => {
+    try {
+      await AuthUserService({
+        email: faker.internet.email(),
+        password: faker.internet.password()
+      });
+    } catch (err) {
+      expect(err).toBeInstanceOf(AppError);
+      expect(err.statusCode).toBe(401);
+      expect(err.message).toBe("ERR_INVALID_CREDENTIALS");
+    }
+  });
+
+  it("should not be able to login with incorret password", async () => {
+    await CreateUserService({
+      name: faker.name.findName(),
+      email: "mail@test.com",
+      password: "hardpassword"
+    });
+
+    try {
+      await AuthUserService({
+        email: "mail@test.com",
+        password: faker.internet.password()
+      });
+    } catch (err) {
+      expect(err).toBeInstanceOf(AppError);
+      expect(err.statusCode).toBe(401);
+      expect(err.message).toBe("ERR_INVALID_CREDENTIALS");
+    }
+  });
+});
diff --git a/backend/src/__tests__/unit/User/CreateUserService.spec.ts b/backend/src/__tests__/unit/User/CreateUserService.spec.ts
new file mode 100644
index 0000000..d6721bc
--- /dev/null
+++ b/backend/src/__tests__/unit/User/CreateUserService.spec.ts
@@ -0,0 +1,47 @@
+import faker from "faker";
+import AppError from "../../../errors/AppError";
+import CreateUserService from "../../../services/UserServices/CreateUserService";
+import { disconnect, truncate } from "../../utils/database";
+
+describe("User", () => {
+  beforeEach(async () => {
+    await truncate();
+  });
+
+  afterEach(async () => {
+    await truncate();
+  });
+
+  afterAll(async () => {
+    await disconnect();
+  });
+
+  it("should be able to create a new user", async () => {
+    const user = await CreateUserService({
+      name: faker.name.findName(),
+      email: faker.internet.email(),
+      password: faker.internet.password()
+    });
+
+    expect(user).toHaveProperty("id");
+  });
+
+  it("should not be able to create a user with duplicated email", async () => {
+    await CreateUserService({
+      name: faker.name.findName(),
+      email: "teste@sameemail.com",
+      password: faker.internet.password()
+    });
+
+    try {
+      await CreateUserService({
+        name: faker.name.findName(),
+        email: "teste@sameemail.com",
+        password: faker.internet.password()
+      });
+    } catch (err) {
+      expect(err).toBeInstanceOf(AppError);
+      expect(err.statusCode).toBe(400);
+    }
+  });
+});
diff --git a/backend/src/__tests__/unit/User/DeleteUserService.spec.ts b/backend/src/__tests__/unit/User/DeleteUserService.spec.ts
new file mode 100644
index 0000000..3fc8372
--- /dev/null
+++ b/backend/src/__tests__/unit/User/DeleteUserService.spec.ts
@@ -0,0 +1,35 @@
+import faker from "faker";
+import AppError from "../../../errors/AppError";
+import CreateUserService from "../../../services/UserServices/CreateUserService";
+import DeleteUserService from "../../../services/UserServices/DeleteUserService";
+import { disconnect, truncate } from "../../utils/database";
+
+describe("User", () => {
+  beforeEach(async () => {
+    await truncate();
+  });
+
+  afterEach(async () => {
+    await truncate();
+  });
+
+  afterAll(async () => {
+    await disconnect();
+  });
+
+  it("should be delete a existing user", async () => {
+    const { id } = await CreateUserService({
+      name: faker.name.findName(),
+      email: faker.internet.email(),
+      password: faker.internet.password()
+    });
+
+    expect(DeleteUserService(id)).resolves.not.toThrow();
+  });
+
+  it("to throw an error if tries to delete a non existing user", async () => {
+    expect(DeleteUserService(faker.random.number())).rejects.toBeInstanceOf(
+      AppError
+    );
+  });
+});
diff --git a/backend/src/__tests__/unit/User/ListUserService.spec.ts b/backend/src/__tests__/unit/User/ListUserService.spec.ts
new file mode 100644
index 0000000..4fa777f
--- /dev/null
+++ b/backend/src/__tests__/unit/User/ListUserService.spec.ts
@@ -0,0 +1,34 @@
+import faker from "faker";
+import User from "../../../models/User";
+import CreateUserService from "../../../services/UserServices/CreateUserService";
+import ListUsersService from "../../../services/UserServices/ListUsersService";
+import { disconnect, truncate } from "../../utils/database";
+
+describe("User", () => {
+  beforeEach(async () => {
+    await truncate();
+  });
+
+  afterEach(async () => {
+    await truncate();
+  });
+
+  afterAll(async () => {
+    await disconnect();
+  });
+
+  it("should be able to list users", async () => {
+    await CreateUserService({
+      name: faker.name.findName(),
+      email: faker.internet.email(),
+      password: faker.internet.password()
+    });
+
+    const response = await ListUsersService({
+      pageNumber: 1
+    });
+
+    expect(response).toHaveProperty("users");
+    expect(response.users[0]).toBeInstanceOf(User);
+  });
+});
diff --git a/backend/src/__tests__/unit/User/ShowUserService.spec.ts b/backend/src/__tests__/unit/User/ShowUserService.spec.ts
new file mode 100644
index 0000000..2883180
--- /dev/null
+++ b/backend/src/__tests__/unit/User/ShowUserService.spec.ts
@@ -0,0 +1,39 @@
+import faker from "faker";
+import AppError from "../../../errors/AppError";
+import User from "../../../models/User";
+import CreateUserService from "../../../services/UserServices/CreateUserService";
+import ShowUserService from "../../../services/UserServices/ShowUserService";
+import { disconnect, truncate } from "../../utils/database";
+
+describe("User", () => {
+  beforeEach(async () => {
+    await truncate();
+  });
+
+  afterEach(async () => {
+    await truncate();
+  });
+
+  afterAll(async () => {
+    await disconnect();
+  });
+
+  it("should be able to find a user", async () => {
+    const newUser = await CreateUserService({
+      name: faker.name.findName(),
+      email: faker.internet.email(),
+      password: faker.internet.password()
+    });
+
+    const user = await ShowUserService(newUser.id);
+
+    expect(user).toHaveProperty("id");
+    expect(user).toBeInstanceOf(User);
+  });
+
+  it("should not be able to find a inexisting user", async () => {
+    expect(ShowUserService(faker.random.number())).rejects.toBeInstanceOf(
+      AppError
+    );
+  });
+});
diff --git a/backend/src/__tests__/unit/User/UpdateUserService.spec.ts b/backend/src/__tests__/unit/User/UpdateUserService.spec.ts
new file mode 100644
index 0000000..496926d
--- /dev/null
+++ b/backend/src/__tests__/unit/User/UpdateUserService.spec.ts
@@ -0,0 +1,68 @@
+import faker from "faker";
+import AppError from "../../../errors/AppError";
+import CreateUserService from "../../../services/UserServices/CreateUserService";
+import UpdateUserService from "../../../services/UserServices/UpdateUserService";
+import { disconnect, truncate } from "../../utils/database";
+
+describe("User", () => {
+  beforeEach(async () => {
+    await truncate();
+  });
+
+  afterEach(async () => {
+    await truncate();
+  });
+
+  afterAll(async () => {
+    await disconnect();
+  });
+
+  it("should be able to find a user", async () => {
+    const newUser = await CreateUserService({
+      name: faker.name.findName(),
+      email: faker.internet.email(),
+      password: faker.internet.password()
+    });
+
+    const updatedUser = await UpdateUserService({
+      userId: newUser.id,
+      userData: {
+        name: "New name",
+        email: "newmail@email.com"
+      }
+    });
+
+    expect(updatedUser).toHaveProperty("name", "New name");
+    expect(updatedUser).toHaveProperty("email", "newmail@email.com");
+  });
+
+  it("should not be able to updated a inexisting user", async () => {
+    const userId = faker.random.number();
+    const userData = {
+      name: faker.name.findName(),
+      email: faker.internet.email()
+    };
+
+    expect(UpdateUserService({ userId, userData })).rejects.toBeInstanceOf(
+      AppError
+    );
+  });
+
+  it("should not be able to updated an user with invalid data", async () => {
+    const newUser = await CreateUserService({
+      name: faker.name.findName(),
+      email: faker.internet.email(),
+      password: faker.internet.password()
+    });
+
+    const userId = newUser.id;
+    const userData = {
+      name: faker.name.findName(),
+      email: "test.worgn.email"
+    };
+
+    expect(UpdateUserService({ userId, userData })).rejects.toBeInstanceOf(
+      AppError
+    );
+  });
+});
diff --git a/backend/src/__tests__/utils/database.ts b/backend/src/__tests__/utils/database.ts
index 0332c63..34645fa 100644
--- a/backend/src/__tests__/utils/database.ts
+++ b/backend/src/__tests__/utils/database.ts
@@ -1,7 +1,7 @@
 import database from "../../database";
 
 const truncate = async (): Promise<void> => {
-  await database.sync({ force: true });
+  await database.truncate({ force: true, cascade: true });
 };
 
 const disconnect = async (): Promise<void> => {
diff --git a/backend/src/services/UserServices/DeleteUserService.ts b/backend/src/services/UserServices/DeleteUserService.ts
index dcd945a..ffaf5f0 100644
--- a/backend/src/services/UserServices/DeleteUserService.ts
+++ b/backend/src/services/UserServices/DeleteUserService.ts
@@ -3,7 +3,7 @@ import AppError from "../../errors/AppError";
 import Ticket from "../../models/Ticket";
 import UpdateDeletedUserOpenTicketsStatus from "../../helpers/UpdateDeletedUserOpenTicketsStatus";
 
-const DeleteUserService = async (id: string): Promise<void> => {
+const DeleteUserService = async (id: string | number): Promise<void> => {
   const user = await User.findOne({
     where: { id }
   });
diff --git a/backend/src/services/UserServices/ListUsersService.ts b/backend/src/services/UserServices/ListUsersService.ts
index 233b5c3..24bd8f0 100644
--- a/backend/src/services/UserServices/ListUsersService.ts
+++ b/backend/src/services/UserServices/ListUsersService.ts
@@ -3,7 +3,7 @@ import User from "../../models/User";
 
 interface Request {
   searchParam?: string;
-  pageNumber?: string;
+  pageNumber?: string | number;
 }
 
 interface Response {
diff --git a/backend/src/services/UserServices/UpdateUserService.ts b/backend/src/services/UserServices/UpdateUserService.ts
index 65a33fb..b0c497b 100644
--- a/backend/src/services/UserServices/UpdateUserService.ts
+++ b/backend/src/services/UserServices/UpdateUserService.ts
@@ -12,7 +12,7 @@ interface UserData {
 
 interface Request {
   userData: UserData;
-  userId: string;
+  userId: string | number;
 }
 
 interface Response {