From 7f193ea0bbe2b2c3f410a97e8df4e40436070468 Mon Sep 17 00:00:00 2001
From: Chris McCord <chris@chrismccord.com>
Date: Fri, 25 Aug 2023 09:56:19 -0400
Subject: [PATCH] WIP

---
 lib/phoenix_live_view/engine.ex      | 22 +++++++++++++++-------
 lib/phoenix_live_view/html_engine.ex |  9 +++++----
 lib/phoenix_live_view/tag_engine.ex  | 14 ++++++++++----
 3 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/lib/phoenix_live_view/engine.ex b/lib/phoenix_live_view/engine.ex
index 91f8b7fd5b..611a2541c4 100644
--- a/lib/phoenix_live_view/engine.ex
+++ b/lib/phoenix_live_view/engine.ex
@@ -391,13 +391,21 @@ defmodule Phoenix.LiveView.Engine do
         analyze_static_and_dynamic(static, dynamic, vars, assigns, caller)
 
       static =
-        if anno = opts[:root_tag_annotation] do
-          case static do
-            [] -> [anno]
-            [first | rest] -> [anno <> first | rest]
-          end
-        else
-          static
+        case Keyword.fetch(opts, :root_tag_annotation) do
+          {:ok, {nil = _before, nil = _aft}} ->
+            static
+
+          {:ok, {before, aft}} ->
+            case static do
+              [] ->
+                ["#{before}#{aft}"]
+
+              [first | rest] ->
+                List.update_at([to_string(before) <> first | rest], -1, &(&1 <> to_string(aft)))
+            end
+
+          :error ->
+            static
         end
 
       changed =
diff --git a/lib/phoenix_live_view/html_engine.ex b/lib/phoenix_live_view/html_engine.ex
index a67167eb80..d872777451 100644
--- a/lib/phoenix_live_view/html_engine.ex
+++ b/lib/phoenix_live_view/html_engine.ex
@@ -59,11 +59,12 @@ defmodule Phoenix.LiveView.HTMLEngine do
     if Application.get_env(:phoenix, :heex_debug_annotations, false) do
       %Macro.Env{module: mod, function: {func, _}, file: file, line: line} = caller
       line = if line == 0, do: 1, else: line
-      file = Path.relative_to_cwd(file)
-      begin = "<#{inspect(mod)}.#{func}> #{file}:#{line}"
-      "<!-- #{begin} -->"
+      # file = Path.relative_to_cwd(file)
+      before = "<#{inspect(mod)}.#{func}> #{file}:#{line}"
+      aft = "</#{inspect(mod)}.#{func}>"
+      {"<!-- #{before} -->", "<!-- #{aft} -->"}
     else
-      nil
+      {nil, nil}
     end
   end
 end
diff --git a/lib/phoenix_live_view/tag_engine.ex b/lib/phoenix_live_view/tag_engine.ex
index 3ac4603fa1..f473ef17df 100644
--- a/lib/phoenix_live_view/tag_engine.ex
+++ b/lib/phoenix_live_view/tag_engine.ex
@@ -40,7 +40,8 @@ defmodule Phoenix.LiveView.TagEngine do
   """
   @callback void?(name :: binary()) :: boolean()
 
-  @callback annotate_root_tag(Macro.Env.t()) :: binary() | nil
+  @callback annotate_root_tag(Macro.Env.t()) ::
+              {anno_before :: binary() | nil, anno_after :: binary() | nil}
 
   @doc """
   Renders a component defined by the given function.
@@ -185,10 +186,15 @@ defmodule Phoenix.LiveView.TagEngine do
       |> handle_tokens(tokens)
       |> validate_unclosed_tags!("template")
 
-    annotation =
-      state.has_tags? && state.caller && state.tag_handler.annotate_root_tag(state.caller)
+    opts = [root: token_state.root || false]
+
+    opts =
+      if state.has_tags? && state.caller do
+        Keyword.put(opts, :root_tag_annotation, state.tag_handler.annotate_root_tag(state.caller))
+      else
+        opts
+      end
 
-    opts = [root: token_state.root || false, root_tag_annotation: annotation]
     ast = invoke_subengine(token_state, :handle_body, [opts])
 
     quote do