Update the UserFactory filename to the snake_case.

lib/link_shortener/accounts/user.ex

@@ -2,12 +2,15 @@ defmodule LinkShortener.Accounts.User do
   use Ecto.Schema
   import Ecto.Changeset
 
+  alias LinkShortener.Links.Link
+
   schema "users" do
     field :email, :string
     field :password, :string, virtual: true, redact: true
     field :hashed_password, :string, redact: true
     field :current_password, :string, virtual: true, redact: true
     field :confirmed_at, :utc_datetime
+    has_many :links, Link
 
     timestamps(type: :utc_datetime)
   end

lib/link_shortener/links/link.ex

@@ -3,10 +3,13 @@ defmodule LinkShortener.Links.Link do
   import Ecto.Changeset
   import Ecto.Query
 
+  alias LinkShortener.Accounts.User
+
   schema "links" do
     field :name, :string
     field :url, :string
     field :shorten, :string
+    belongs_to :user, User
 
     timestamps()
   end
@@ -14,8 +17,8 @@ defmodule LinkShortener.Links.Link do
   @doc false
   def changeset(link, attrs) do
     link
-    |> cast(attrs, [:name, :url, :shorten])
-    |> validate_required([:url, :shorten])
+    |> cast(attrs, [:name, :url, :shorten, :user_id])
+    |> validate_required([:url, :shorten, :user_id])
     |> unique_constraint(:shorten)
   end
 end

lib/link_shortener_web/controllers/api/v1/link_controller.ex

@@ -12,6 +12,12 @@ defmodule LinkShortenerWeb.Api.V1.LinkController do
   end
 
   def create(conn, %{"link" => link_params}) do
+    user = Guardian.Plug.current_resource(conn)
+
+    link_params =
+      link_params
+      |> Map.put("user_id", user.id)
+
     with {:ok, %Link{} = link} <- Links.insert_one(link_params) do
       conn
       |> put_status(:created)

priv/repo/migrations/20240901105600_add_relationship_between_users_and_links.exs

@@ -0,0 +1,11 @@
+defmodule LinkShortener.Repo.Migrations.AddRelationshipBetweenUsersAndLinks do
+  use Ecto.Migration
+
+  def change do
+    alter table(:links) do
+      add :user_id, references(:users, on_delete: :delete_all), null: false
+    end
+
+    create index(:links, [:user_id])
+  end
+end

test/link_shortener/links_test.exs

@@ -2,6 +2,11 @@ defmodule LinkShortener.LinksTest do
   use LinkShortener.DataCase
 
   alias LinkShortener.Links
+  alias LinkShortener.Links.Link
+
+  alias LinkShortener.Factories.UserFactory
+
+  import LinkShortener.LinksFixtures
 
   @create_attrs %{
     name: "some link name",
@@ -23,31 +28,40 @@ defmodule LinkShortener.LinksTest do
     shorten: nil,
   }
 
-  describe "links" do
-    alias LinkShortener.Links.Link
-
-    import LinkShortener.LinksFixtures
+  setup do
+    {:ok, user: UserFactory.create_user()}
+  end
 
+  describe "links" do
     test "new_one/1 returns the changeset" do
       assert %Ecto.Changeset{} = Links.new_one()
     end
 
-    test "create_one/1 with valid data creates a link" do
-      assert {:ok, %Link{} = link} = Links.create_one(@create_generated_attrs)
+    test "create_one/1 with valid data creates a link", %{user: user} do
+      assert {:ok, %Link{} = link} =
+	with_user(@create_generated_attrs, user)
+	|> Links.create_one()
+
       assert link.name == "some link name"
       assert link.url == "https://gitlab.com/KKlochko/link_shortener"
       assert String.length(link.shorten) == 10
     end
 
-    test "create_one/2 with valid data creates a link" do
-      assert {:ok, %Link{} = link} = Links.create_one(@create_generated_attrs, 5)
+    test "create_one/2 with valid data creates a link", %{user: user} do
+      assert {:ok, %Link{} = link} =
+	with_user(@create_generated_attrs, user)
+	|> Links.create_one(5)
+
       assert link.name == "some link name"
       assert link.url == "https://gitlab.com/KKlochko/link_shortener"
       assert String.length(link.shorten) == 5
     end
 
-    test "insert_one/1 with valid data creates a link" do
-      assert {:ok, %Link{} = link} = Links.insert_one(@create_attrs)
+    test "insert_one/1 with valid data creates a link", %{user: user} do
+      assert {:ok, %Link{} = link} =
+	with_user(@create_attrs, user)
+	|> Links.insert_one()
+
       assert link.name == "some link name"
       assert link.url == "https://gitlab.com/KKlochko/link_shortener"
       assert link.shorten == "git_repo"
@@ -103,4 +117,9 @@ defmodule LinkShortener.LinksTest do
       assert_raise Ecto.NoResultsError, fn -> Links.get_one!(link.id) end
     end
   end
+
+  defp with_user(attrs, user) do
+    attrs
+    |> Map.put(:user_id, user.id)
+  end
 end

test/support/factories/link_factory.ex

@@ -0,0 +1,39 @@
+defmodule LinkShortener.Factories.LinkFactory do
+  use ExMachina
+
+  alias LinkShortener.Links
+  alias LinkShortener.Factories.UserFactory
+
+  def link_attrs_factory() do
+    %{
+      name: sequence(:name, &"name-#{&1}"),
+      url: "https://gitlab.com/KKlochko/link_shortener",
+      shorten: sequence(:shorten, &"shorten#{&1}"),
+    }
+  end
+
+  @doc """
+  Create a link that has a static url, a random name and a random shorten.
+  If there are no user_id in attrs, then a new user will be created.
+  """
+  def create_link(attrs \\ %{}) do
+    {:ok, link} =
+      link_attrs_factory()
+      |> put_new_user_id()
+      |> Map.merge(attrs)
+      |> Links.create_one()
+
+    link
+  end
+
+  defp put_new_user_id(attrs) do
+    if Map.has_key?(attrs, :user_id) do
+      attrs
+    else
+      user = UserFactory.create_user()
+
+      attrs
+      |> Map.put(:user_id, user.id)
+    end
+  end
+end

test/support/factories/user_factory.ex

@@ -1,10 +1,15 @@
 defmodule LinkShortener.Factories.UserFactory do
   use ExMachina
 
-  def user_factory do
+  def user_attrs_factory() do
     %{
       email: sequence(:email, &"user-#{&1}@mail.com"),
       password: "some password"
     }
   end
+
+  def create_user() do
+    user_attrs_factory()
+    |> LinkShortener.AccountsFixtures.user_fixture()
+  end
 end

test/support/fixtures/accounts_fixtures.ex

@@ -32,7 +32,7 @@ defmodule LinkShortener.AccountsFixtures do
   end
 
   def user_token_fixture(attrs \\ %{}) do
-    user_params = UserFactory.user_factory()
+    user_params = UserFactory.user_attrs_factory()
 
     {:ok, %User{} = user} = Accounts.register_user(user_params)
     {:ok, token, _claims} = Guardian.encode_and_sign(user)

test/support/fixtures/links_fixtures.ex

@@ -4,21 +4,12 @@ defmodule LinkShortener.LinksFixtures do
   entities via the `LinkShortener.Links` context.
   """
 
-  alias LinkShortener.Links
+  alias LinkShortener.Factories.LinkFactory
 
   @doc """
   Generate a link.
   """
   def link_fixture(attrs \\ %{}) do
-    {:ok, link} =
-      attrs
-      |> Enum.into(%{
-        name: "some name",
-	url: "https://gitlab.com/KKlochko/link_shortener",
-	shorten: "api-article",
-      })
-      |> Links.create_one()
-
-    link
+    LinkFactory.create_link(attrs)
   end
 end