Add the configuration for wallaby.

config/test.exs

@@ -21,7 +21,7 @@ config :link_shortener, LinkShortener.Repo,
 config :link_shortener, LinkShortenerWeb.Endpoint,
   http: [ip: {127, 0, 0, 1}, port: 4002],
   secret_key_base: System.get_env("SECRET_KEY_BASE"),
-  server: false
+  server: true
 
 # In test we don't send emails
 config :link_shortener, LinkShortener.Mailer, adapter: Swoosh.Adapters.Test
@@ -38,3 +38,10 @@ config :phoenix, :plug_init_mode, :runtime
 # Enable helpful, but potentially expensive runtime checks
 config :phoenix_live_view,
   enable_expensive_runtime_checks: true
+
+config :wallaby,
+  otp_app: :link_shortener,
+  screenshot_on_failure: true,
+  screenshot_dir: "screenshots",
+  driver: Wallaby.Selenium
+

lib/link_shortener_web/endpoint.ex

@@ -12,7 +12,7 @@ defmodule LinkShortenerWeb.Endpoint do
   ]
 
   socket "/live", Phoenix.LiveView.Socket,
-    websocket: [connect_info: [session: @session_options]],
+    websocket: [connect_info: [:user_agent, session: @session_options]],
     longpoll: [connect_info: [session: @session_options]]
 
   # Serve at "/" the static files from "priv/static" directory.

test/test_helper.exs

@@ -1,2 +1,5 @@
 ExUnit.start()
 Ecto.Adapters.SQL.Sandbox.mode(LinkShortener.Repo, :manual)
+
+{:ok, _} = Application.ensure_all_started(:wallaby)
+Application.put_env(:wallaby, :base_url, LinkShortenerWeb.Endpoint.url)