only raise by default in later release

CHANGELOG.md

@@ -124,7 +124,7 @@ generated user module:
 * Fix client hooks with dynamic IDs not being destroyed properly when parts of the DOM are locked ([#3651](https://github.com/phoenixframework/phoenix_live_view/issues/3651))
 
 ### Enhancements
-* Raise again for duplicate IDs detected in LiveViewTest, but allow to change it to a warning by passing `on_error: :warn` to `Phoenix.LiveViewTest.live/3` / `Phoenix.LiveViewTest.live_isolated/3` ([#3653](https://github.com/phoenixframework/phoenix_live_view/pull/3653))
+* Allow to configure if duplicate IDs / other detected errors should warn or raise by passing `on_error` to `Phoenix.LiveViewTest.live/3` / `Phoenix.LiveViewTest.live_isolated/3` ([#3653](https://github.com/phoenixframework/phoenix_live_view/pull/3653))
 * Also detect duplicate LiveComponents that are added dynamically to the page in LiveViewTest ([#3653](https://github.com/phoenixframework/phoenix_live_view/pull/3653))
 * Log an error in the JavaScript console when detecting a stream container with missing `phx-update="stream"` attribute ([#3645](https://github.com/phoenixframework/phoenix_live_view/pull/3645))
 * Update documentation to mention `:fun` and `{:fun, arity}` as valid attribute types for `Phoenix.Component.attr/3` ([#3635](https://github.com/phoenixframework/phoenix_live_view/pull/3635))

lib/phoenix_live_view/test/client_proxy.ex

@@ -23,7 +23,7 @@ defmodule Phoenix.LiveViewTest.ClientProxy do
             uri: nil,
             connect_params: %{},
             connect_info: %{},
-            on_error: :raise
+            on_error: :warn
 
   alias Plug.Conn.Query
   alias Phoenix.LiveViewTest.{ClientProxy, DOM, Element, View, Upload}
@@ -491,7 +491,13 @@ defmodule Phoenix.LiveViewTest.ClientProxy do
         """
 
       :warn ->
-        IO.warn(error, [])
+        IO.warn("""
+        #{String.trim(error)}
+
+        You can change this to raise and fail your test instead of warning
+        by passing `on_error: :raise` to `Phoenix.LiveViewTest.live/3` or
+        `Phoenix.LiveViewTest.live_isolated/3`.
+        """, [])
     end
 
     {:noreply, state}

lib/phoenix_live_view/test/live_view_test.ex

@@ -207,7 +207,7 @@ defmodule Phoenix.LiveViewTest do
 
     * `:on_error` - Can be either `:raise` or `:warn` to control whether
        detected errors like duplicate IDs or live components fail the test or just log
-       a warning. Defaults to `:raise`.
+       a warning. Defaults to `:warn`.
 
   ## Examples
 
@@ -246,7 +246,7 @@ defmodule Phoenix.LiveViewTest do
     * `:session` - the session to be given to the LiveView
     * `:on_error` - Can be either `:raise` or `:warn` to control whether
        detected errors like duplicate IDs or live components fail the test or just log
-       a warning. Defaults to `:raise`.
+       a warning. Defaults to `:warn`.
 
   All other options are forwarded to the LiveView for rendering. Refer to
   `Phoenix.Component.live_render/3` for a list of supported render
@@ -347,7 +347,7 @@ defmodule Phoenix.LiveViewTest do
       endpoint: Phoenix.Controller.endpoint_module(conn),
       session: maybe_get_session(conn),
       url: Plug.Conn.request_url(conn),
-      on_error: opts[:on_error] || :raise
+      on_error: opts[:on_error] || :warn
     })
   end
 

test/phoenix_live_view/integrations/live_view_test.exs

@@ -152,15 +152,6 @@ defmodule Phoenix.LiveView.LiveViewTest do
       assert html =~ ~s|class="foo bar"|
     end
 
-    test "raises for duplicate ids by default", %{conn: conn} do
-      Process.flag(:trap_exit, true)
-
-      {:ok, view, _html} = live(conn, "/duplicate-id")
-      {{exception, _}, _} = catch_exit(render(view))
-      assert Exception.message(exception) =~ "Duplicate id found while testing LiveView: a"
-      assert_receive {:EXIT, _, _}
-    end
-
     test "raises for duplicate ids when on_error: :raise", %{conn: conn} do
       Process.flag(:trap_exit, true)
 
@@ -170,22 +161,6 @@ defmodule Phoenix.LiveView.LiveViewTest do
       assert_receive {:EXIT, _, _}
     end
 
-    test "raises for duplicate components by default", %{conn: conn} do
-      Process.flag(:trap_exit, true)
-
-      {:ok, view, _html} = live(conn, "/dynamic-duplicate-component", on_error: :raise)
-      view |> element("button", "Toggle duplicate LC") |> render_click() =~ "I am LiveComponent2"
-
-      {{exception, _}, _} = catch_exit(render(view))
-
-      message = Exception.message(exception)
-      assert message =~ "Duplicate live component found while testing LiveView:"
-      assert message =~ "I am LiveComponent2"
-      refute message =~ "I am a LC inside nested LV"
-
-      assert_receive {:EXIT, _, _}
-    end
-
     test "raises for duplicate components when on_error: :raise", %{conn: conn} do
       Process.flag(:trap_exit, true)
 
@@ -439,18 +414,6 @@ defmodule Phoenix.LiveView.LiveViewTest do
       end
     end
 
-    test "raises for duplicate ids by default" do
-      Process.flag(:trap_exit, true)
-
-      {:ok, view, _html} =
-        live_isolated(Phoenix.ConnTest.build_conn(), Phoenix.LiveViewTest.Support.DuplicateIdLive)
-
-      # errors are detected asynchronously, so we need to render again for the message to be processed
-      {{exception, _}, _} = catch_exit(render(view))
-      assert Exception.message(exception) =~ "Duplicate id found while testing LiveView: a"
-      assert_receive {:EXIT, _, _}
-    end
-
     test "raises for duplicate ids when on_error: raise" do
       Process.flag(:trap_exit, true)
 
@@ -464,26 +427,6 @@ defmodule Phoenix.LiveView.LiveViewTest do
       assert_receive {:EXIT, _, _}
     end
 
-    test "raises for duplicate components by default" do
-      Process.flag(:trap_exit, true)
-
-      {:ok, view, _html} =
-        live_isolated(
-          Phoenix.ConnTest.build_conn(),
-          Phoenix.LiveViewTest.Support.DynamicDuplicateComponentLive
-        )
-
-      view |> element("button", "Toggle duplicate LC") |> render_click() =~ "I am LiveComponent2"
-
-      # errors are detected asynchronously, so we need to render again for the message to be processed
-      {{exception, _}, _} = catch_exit(render(view))
-
-      assert Exception.message(exception) =~
-               "Duplicate live component found while testing LiveView:"
-
-      assert_receive {:EXIT, _, _}
-    end
-
     test "raises for duplicate components when on_error: raise" do
       Process.flag(:trap_exit, true)
 

test/phoenix_live_view/integrations/live_view_test_warnings_test.exs

@@ -11,6 +11,21 @@ defmodule Phoenix.LiveView.LiveViewTestWarningsTest do
   @endpoint Endpoint
 
   describe "live" do
+    test "warns for duplicate ids by default" do
+      conn = Plug.Test.init_test_session(Phoenix.ConnTest.build_conn(), %{})
+      conn = get(conn, "/duplicate-id")
+
+      Process.flag(:trap_exit, true)
+
+      assert capture_io(:stderr, fn ->
+               {:ok, view, _html} = live(conn, nil)
+               render(view)
+             end) =~
+               "Duplicate id found while testing LiveView: a"
+
+      refute_receive {:EXIT, _, _}
+    end
+
     test "warns for duplicate ids when on_error: warn" do
       conn = Plug.Test.init_test_session(Phoenix.ConnTest.build_conn(), %{})
       conn = get(conn, "/duplicate-id")
@@ -26,6 +41,29 @@ defmodule Phoenix.LiveView.LiveViewTestWarningsTest do
       refute_receive {:EXIT, _, _}
     end
 
+    test "warns for duplicate component by default" do
+      conn = Plug.Test.init_test_session(Phoenix.ConnTest.build_conn(), %{})
+      conn = get(conn, "/dynamic-duplicate-component")
+
+      Process.flag(:trap_exit, true)
+
+      warning =
+        capture_io(:stderr, fn ->
+          {:ok, view, _html} = live(conn, nil)
+
+          view |> element("button", "Toggle duplicate LC") |> render_click() =~
+            "I am LiveComponent2"
+
+          render(view)
+        end)
+
+      assert warning =~ "Duplicate live component found while testing LiveView:"
+      assert warning =~ "I am LiveComponent2"
+      refute warning =~ "I am a LC inside nested LV"
+
+      refute_receive {:EXIT, _, _}
+    end
+
     test "warns for duplicate component when on_error: warn" do
       conn = Plug.Test.init_test_session(Phoenix.ConnTest.build_conn(), %{})
       conn = get(conn, "/dynamic-duplicate-component")
@@ -51,6 +89,23 @@ defmodule Phoenix.LiveView.LiveViewTestWarningsTest do
   end
 
   describe "live_isolated" do
+    test "warns for duplicate ids by default" do
+      Process.flag(:trap_exit, true)
+
+      assert capture_io(:stderr, fn ->
+               {:ok, view, _html} =
+                 live_isolated(
+                   Phoenix.ConnTest.build_conn(),
+                   Phoenix.LiveViewTest.Support.DuplicateIdLive
+                 )
+
+               render(view)
+             end) =~
+               "Duplicate id found while testing LiveView: a"
+
+      refute_receive {:EXIT, _, _}
+    end
+
     test "warns for duplicate ids when on_error: warn" do
       Process.flag(:trap_exit, true)
 
@@ -69,6 +124,30 @@ defmodule Phoenix.LiveView.LiveViewTestWarningsTest do
       refute_receive {:EXIT, _, _}
     end
 
+    test "warns for duplicate component by default" do
+      Process.flag(:trap_exit, true)
+
+      warning =
+        capture_io(:stderr, fn ->
+          {:ok, view, _html} =
+            live_isolated(
+              Phoenix.ConnTest.build_conn(),
+              Phoenix.LiveViewTest.Support.DynamicDuplicateComponentLive
+            )
+
+          view |> element("button", "Toggle duplicate LC") |> render_click() =~
+            "I am LiveComponent2"
+
+          render(view)
+        end)
+
+      assert warning =~ "Duplicate live component found while testing LiveView:"
+      assert warning =~ "I am LiveComponent2"
+      refute warning =~ "I am a LC inside nested LV"
+
+      refute_receive {:EXIT, _, _}
+    end
+
     test "warns for duplicate component when on_error: warn" do
       Process.flag(:trap_exit, true)