diff --git a/CHANGELOG.org b/CHANGELOG.org
index 0063100..def71de 100644
--- a/CHANGELOG.org
+++ b/CHANGELOG.org
@@ -53,3 +53,5 @@
     Add User model.
 ** 0.7.0 <2023-08-05 Sat>
     Add the API Authentication.
+** 0.7.1 <2023-08-06 Sun>
+    Add tests for UserController, Accounts, Generators.
diff --git a/test/link_shortener/accounts/accounts_test.exs b/test/link_shortener/accounts/accounts_test.exs
new file mode 100644
index 0000000..0800db7
--- /dev/null
+++ b/test/link_shortener/accounts/accounts_test.exs
@@ -0,0 +1,61 @@
+defmodule LinkShortener.AccountsTest do
+  use LinkShortener.DataCase
+
+  alias LinkShortener.Accounts
+
+  describe "users" do
+    alias LinkShortener.Accounts.User
+
+    import LinkShortener.AccountsFixtures
+
+    @invalid_attrs %{email: nil, password: nil}
+
+    test "list_users/0 returns all users" do
+      user = user_fixture()
+      assert Accounts.list_users() == [user]
+    end
+
+    test "get_user!/1 returns the user with given id" do
+      user = user_fixture()
+      assert Accounts.get_user!(user.id) == user
+    end
+
+    test "create_user/1 with valid data creates a user" do
+      valid_attrs = %{email: "some email", password: "some encrypted_password"}
+
+      assert {:ok, %User{} = user} = Accounts.create_user(valid_attrs)
+      assert user.email == "some email"
+      assert user.encrypted_password != "some encrypted_password"
+    end
+
+    test "create_user/1 with invalid data returns error changeset" do
+      assert {:error, %Ecto.Changeset{}} = Accounts.create_user(@invalid_attrs)
+    end
+
+    test "update_user/2 with valid data updates the user" do
+      user = user_fixture()
+      update_attrs = %{email: "some updated email", password: "some updated encrypted_password"}
+
+      assert {:ok, %User{} = user} = Accounts.update_user(user, update_attrs)
+      assert user.email == "some updated email"
+      assert user.encrypted_password != "some updated encrypted_password"
+    end
+
+    test "update_user/2 with invalid data returns error changeset" do
+      user = user_fixture()
+      assert {:error, %Ecto.Changeset{}} = Accounts.update_user(user, @invalid_attrs)
+      assert user == Accounts.get_user!(user.id)
+    end
+
+    test "delete_user/1 deletes the user" do
+      user = user_fixture()
+      assert {:ok, %User{}} = Accounts.delete_user(user)
+      assert_raise Ecto.NoResultsError, fn -> Accounts.get_user!(user.id) end
+    end
+
+    test "change_user/1 returns a user changeset" do
+      user = user_fixture()
+      assert %Ecto.Changeset{} = Accounts.change_user(user)
+    end
+  end
+end
diff --git a/test/link_shortener/generators/link_with_random_shorten_test.exs b/test/link_shortener/generators/link_with_random_shorten_test.exs
new file mode 100644
index 0000000..fbec07c
--- /dev/null
+++ b/test/link_shortener/generators/link_with_random_shorten_test.exs
@@ -0,0 +1,44 @@
+defmodule LinkShortener.Generators.LinkWithRandomShortenTest do
+  use ExUnit.Case, async: true
+  
+  alias LinkShortener.Generators.LinkWithRandomShorten
+
+  @name "Some name"
+  @attrs %{
+    name: @name
+  }
+  
+  test "generate/1 returns random safe string with 10 as length" do
+    assert %{
+      name: @name,
+      shorten: shorten
+    } = LinkWithRandomShorten.generate_one(@attrs)
+
+    assert String.length(shorten) == 10
+  end
+
+  test "generate/2 returns random safe string with 5 as length" do
+    expected_length = 5
+
+    assert %{
+      name: @name,
+      shorten: shorten
+    } = LinkWithRandomShorten.generate_one(@attrs, expected_length)
+
+    assert String.length(shorten) == expected_length
+  end
+
+  test "generate/3 returns random safe string using a lambda function" do
+    random_generator = fn _ -> "random_shorten" end
+    expected_shorten = random_generator.(14) 
+    expected_length = expected_shorten |> String.length()
+
+    assert %{
+      name: @name,
+      shorten: shorten
+    } = LinkWithRandomShorten.generate_one(@attrs, expected_length, random_generator)
+
+    assert String.length(shorten) == expected_length
+    assert shorten == expected_shorten
+  end
+end
diff --git a/test/link_shortener/generators/safe_string_test.exs b/test/link_shortener/generators/safe_string_test.exs
new file mode 100644
index 0000000..e97a52e
--- /dev/null
+++ b/test/link_shortener/generators/safe_string_test.exs
@@ -0,0 +1,17 @@
+defmodule LinkShortener.Generators.SafeStringTest do
+  use ExUnit.Case, async: true
+
+  alias LinkShortener.Generators.SafeString
+
+  @lengths [1, 2, 5, 10]
+  
+  test "generate/1 returns random safe string with same length" do
+    for expected_length <- @lengths do
+      length = expected_length
+      |> SafeString.generate()
+      |> String.length()
+      
+      assert length = expected_length
+    end
+  end
+end
diff --git a/test/link_shortener_web/controllers/api/v1/user_controller_test.exs b/test/link_shortener_web/controllers/api/v1/user_controller_test.exs
new file mode 100644
index 0000000..40a26e5
--- /dev/null
+++ b/test/link_shortener_web/controllers/api/v1/user_controller_test.exs
@@ -0,0 +1,46 @@
+defmodule LinkShortenerWeb.Api.V1.UserControllerTest do
+  use LinkShortenerWeb.ConnCase
+
+  import LinkShortener.AccountsFixtures
+
+  alias LinkShortener.Accounts.User
+
+  @create_attrs %{
+    email: "some_email@mail.com",
+    password: "some password"
+  }
+
+  @update_attrs %{
+    email: "some updated email",
+    password: "some updated password"
+  }
+
+  @invalid_attrs %{
+    email: nil,
+    encrypted_password: nil
+  }
+
+  setup %{conn: conn} do
+    {:ok, conn: put_req_header(conn, "accept", "application/json")}
+  end
+
+  describe "create user" do
+    test "renders user when data is valid", %{conn: conn} do
+      conn = post(conn, Routes.v1_user_path(conn, :create), user: @create_attrs)
+      assert %{
+	"email" => "some_email@mail.com",
+	"token" => token
+      } = json_response(conn, 201)
+    end
+
+    test "renders errors when data is invalid", %{conn: conn} do
+      conn = post(conn, Routes.v1_user_path(conn, :create), user: @invalid_attrs)
+      assert json_response(conn, 422)["errors"] != %{}
+    end
+  end
+
+  defp create_user(_) do
+    user = user_fixture()
+    %{user: user}
+  end
+end
diff --git a/test/support/fixtures/accounts_fixtures.ex b/test/support/fixtures/accounts_fixtures.ex
new file mode 100644
index 0000000..217ebd4
--- /dev/null
+++ b/test/support/fixtures/accounts_fixtures.ex
@@ -0,0 +1,26 @@
+defmodule LinkShortener.AccountsFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `LinkShortener.Accounts` context.
+  """
+
+  @doc """
+  Generate a unique user email.
+  """
+  def unique_user_email, do: "some email#{System.unique_integer([:positive])}"
+
+  @doc """
+  Generate a new user.
+  """
+  def user_fixture(attrs \\ %{}) do
+    {:ok, user} =
+      attrs
+      |> Enum.into(%{
+        email: unique_user_email(),
+        password: "some encrypted_password"
+      })
+      |> LinkShortener.Accounts.create_user()
+
+    LinkShortener.Accounts.get_user!(user.id)
+  end
+end