feat(chat): add username to users

And use it instead of hacky email transformation.

lib/slax/accounts/user.ex

@@ -7,6 +7,7 @@ defmodule Slax.Accounts.User do
 
   schema "users" do
     field :email, :string
+    field :username, :string
     field :password, :string, virtual: true, redact: true
     field :hashed_password, :string, redact: true
     field :current_password, :string, virtual: true, redact: true

lib/slax_web/live/chat_room_live.ex

@@ -98,7 +98,7 @@ defmodule SlaxWeb.ChatRoomLive do
         <ul class="relative z-10 flex items-center gap-4 px-4 sm:px-6 lg:px-8 justify-end">
           <%= if @current_user do %>
             <li class="text-[0.8125rem] leading-6 text-zinc-900">
-              {username(@current_user)}
+              {@current_user.username}
             </li>
             <li>
               <.link
@@ -469,7 +469,7 @@ defmodule SlaxWeb.ChatRoomLive do
           <span class="w-2 h-2 rounded-full border-2 border-gray-500"></span>
         <% end %>
       </div>
-      <span class="ml-2 leading-none">{username(@user)}</span>
+      <span class="ml-2 leading-none">{@user.username}</span>
     </.link>
     """
   end
@@ -526,7 +526,7 @@ defmodule SlaxWeb.ChatRoomLive do
       <div class="ml-2">
         <div class="-mt-1">
           <.link class="text-sm font-semibold hover:underline">
-            <span>{username(@message.user)}</span>
+            <span>{@message.user.username}</span>
           </.link>
           <span :if={@timezone} class="ml-1 text-xs text-gray-500">
             {message_timestamp(@message, @timezone)}
@@ -538,10 +538,6 @@ defmodule SlaxWeb.ChatRoomLive do
     """
   end
 
-  defp username(user) do
-    user.email |> String.split("@") |> List.first() |> String.capitalize()
-  end
-
   defp message_timestamp(message, timezone) do
     message.inserted_at
     |> Timex.Timezone.convert(timezone)

priv/repo/migrations/20250205000835_alter_users_add_username.exs

@@ -0,0 +1,25 @@
+defmodule Slax.Repo.Migrations.AlterUsersAddUsername do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add :username, :citext
+    end
+
+    query = """
+    update
+      users
+    set
+      username = initcap(substring(email from '^[^@]+'))
+    ;
+    """
+
+    execute query, ""
+
+    alter table(:users) do
+      modify :username, :citext, null: false, from: {:citext, null: true}
+    end
+
+    create unique_index(:users, :username)
+  end
+end