Installation: don't crash when socket reconnects and finds no changes (…

…#4520)

lib/plausible_web/live/installation.ex

@@ -400,8 +400,15 @@ defmodule PlausibleWeb.Live.Installation do
 
     flash = snippet_change_flash(socket.assigns.script_config, new_params)
 
+    socket =
+      if flash do
+        put_live_flash(socket, :success, flash)
+      else
+        socket
+      end
+
     socket = update_uri_params(socket, new_params)
-    {:noreply, put_live_flash(socket, :success, flash)}
+    {:noreply, socket}
   end
 
   def handle_params(params, _uri, socket) do
@@ -518,13 +525,14 @@ defmodule PlausibleWeb.Live.Installation do
 
   defp snippet_change_flash(old_config, new_config) do
     change =
-      Enum.find(new_config, fn {key, value} ->
-        if old_config[key] != new_config[key] do
-          {key, value}
-        end
+      Enum.find(new_config, fn {key, _value} ->
+        old_config[key] != new_config[key]
       end)
 
     case change do
+      nil ->
+        nil
+
       {k, false} when k in ["outbound-links", "file-downloads", "404"] ->
         "Snippet updated and goal deleted. Please insert the newest snippet into your site"
 

test/plausible_web/live/installation_test.exs

@@ -326,6 +326,20 @@ defmodule PlausibleWeb.Live.InstallationTest do
 
       assert render(lv) =~ "Snippet updated. Please insert the newest snippet into your site"
     end
+
+    test "no changes", %{conn: conn, site: site} do
+      {lv, _html} = get_lv(conn, site, "?installation_type=manual")
+
+      lv
+      |> element(~s|form#snippet-form|)
+      |> render_change(%{})
+
+      lv
+      |> element(~s|form#snippet-form|)
+      |> render_change(%{})
+
+      refute render(lv) =~ "Snippet updated"
+    end
   end
 
   defp stub_fetch_body(f) when is_function(f, 1) do