From 6ef803f95bf1b0046e0d115efbd88ba1d0fbdc3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Valim?= <jose.valim@dashbit.co>
Date: Sat, 25 Mar 2023 21:52:18 +0100
Subject: [PATCH] Fix 404 rendering, closes #1826

---
 config/config.exs                             |  3 ++-
 test/livebook_web/controllers/errors_test.exs | 12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 test/livebook_web/controllers/errors_test.exs

diff --git a/config/config.exs b/config/config.exs
index 1918818f9..76e5d6cd1 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -5,7 +5,8 @@ config :livebook, LivebookWeb.Endpoint,
   url: [host: "localhost", path: "/"],
   pubsub_server: Livebook.PubSub,
   live_view: [signing_salt: "livebook"],
-  drainer: [shutdown: 1000]
+  drainer: [shutdown: 1000],
+  render_errors: [formats: [html: LivebookWeb.ErrorHTML], layout: false]
 
 # Configures Elixir's Logger
 config :logger, :console,
diff --git a/test/livebook_web/controllers/errors_test.exs b/test/livebook_web/controllers/errors_test.exs
new file mode 100644
index 000000000..422c5379d
--- /dev/null
+++ b/test/livebook_web/controllers/errors_test.exs
@@ -0,0 +1,12 @@
+defmodule LivebookWeb.ErrorsTest do
+  use LivebookWeb.ConnCase, async: true
+
+  test "renders 404", %{conn: conn} do
+    response = assert_error_sent :not_found, fn ->
+      get(conn, "/this/does/not/exist")
+    end
+
+    assert {404, _, body} = response
+    assert body =~ "No Numbats here!"
+  end
+end