Ensure the dashboard compiles without optional deps

.github/workflows/ci.yml

@@ -40,7 +40,7 @@ jobs:
     - run: mix compile --warnings-as-errors
       if: matrix.warnings_as_errors
     - name: Run Tests
-      run: mix test
+      run: mix test --include integration
 
   npm_test:
     name: npm test

.gitignore

@@ -23,3 +23,4 @@ erl_crash.dump
 phoenix_live_dashboard-*.tar
 
 node_modules
+tmp

lib/phoenix/live_dashboard/pages/ecto_stats_page.ex

@@ -117,6 +117,9 @@ defmodule Phoenix.LiveDashboard.EctoStatsPage do
 
   # Phoenix.HMTL.Safe may be not be implemented for Decimal
   # if PhoenixEcto is not available, so we handle it here.
-  defp convert_value(%Decimal{} = decimal), do: Decimal.to_string(decimal)
-  defp convert_value(value), do: value
+  defp convert_value(%struct{} = decimal) when struct == Decimal,
+    do: Decimal.to_string(decimal)
+
+  defp convert_value(value),
+    do: value
 end

test/phoenix/live_dashboard_test.exs

@@ -26,4 +26,30 @@ defmodule Phoenix.LiveDashboardTest do
            |> html_response(200) =~
              ~s|<script nonce="abcdef">|
   end
+
+  @tag :integration
+  test "compiles as a dep without optional deps" do
+    File.rm_rf!("tmp/as_a_dep")
+    File.mkdir_p!("tmp/as_a_dep")
+
+    File.cd!("tmp/as_a_dep", fn ->
+      File.write!("mix.exs", """
+      defmodule DepsOnDashboard.MixProject do
+        use Mix.Project
+
+        def project do
+          [
+            app: :deps_on_dashboard,
+            version: "0.0.1",
+            deps_path: "../../deps",
+            lockfile: "../../mix.lock",
+            deps: [{:phoenix_live_dashboard, path: "../.."}]
+          ]
+        end
+      end
+      """)
+
+      assert {_, 0} = System.cmd("mix", ["compile"], stderr_to_stdout: true)
+    end)
+  end
 end

test/test_helper.exs

@@ -106,4 +106,4 @@ Supervisor.start_link(
   strategy: :one_for_one
 )
 
-ExUnit.start()
+ExUnit.start(exclude: :integration)