From b44863b16420ff39417336d6361edfe150de3e81 Mon Sep 17 00:00:00 2001
From: Thiago Trannin <51510921+thinety@users.noreply.github.com>
Date: Thu, 22 Feb 2024 18:15:21 -0300
Subject: [PATCH] Add compile error when comment and doctype tags are used
 within `view!`

Currently, these tags are not displayed in the rendered view. Instead
of silently doing so, this change introduces a compile error with a
helpful message.
---
 leptos_macro/src/view/client_builder.rs  | 34 ++++++++++++++++++++++--
 leptos_macro/src/view/server_template.rs | 34 ++++++++++++++++++++++--
 2 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/leptos_macro/src/view/client_builder.rs b/leptos_macro/src/view/client_builder.rs
index 15e0151c4a..4487243c7f 100644
--- a/leptos_macro/src/view/client_builder.rs
+++ b/leptos_macro/src/view/client_builder.rs
@@ -120,7 +120,22 @@ pub(crate) fn node_to_tokens(
             global_class,
             view_marker,
         ),
-        Node::Comment(_) | Node::Doctype(_) => Some(quote! {}),
+        Node::Comment(_) => {
+            proc_macro_error::emit_error!(
+                node,
+                "comment tags do not show up in rendered output\nsupport for \
+                 this is coming in leptos 0.7"
+            );
+            Some(quote! {})
+        }
+        Node::Doctype(_) => {
+            proc_macro_error::emit_error!(
+                node,
+                "doctype tags do not show up in rendered output\nsupport for \
+                 this is coming in leptos 0.7"
+            );
+            Some(quote! {})
+        }
         Node::Text(node) => Some(quote! {
             ::leptos::leptos_dom::html::text(#node)
         }),
@@ -333,7 +348,22 @@ pub(crate) fn element_to_tokens(
                     .unwrap_or_default(),
                     false,
                 ),
-                Node::Comment(_) | Node::Doctype(_) => (quote! {}, false),
+                Node::Comment(_) => {
+                    proc_macro_error::emit_error!(
+                        node,
+                        "comment tags do not show up in rendered \
+                         output\nsupport for this is coming in leptos 0.7"
+                    );
+                    (quote! {}, false)
+                }
+                Node::Doctype(_) => {
+                    proc_macro_error::emit_error!(
+                        node,
+                        "doctype tags do not show up in rendered \
+                         output\nsupport for this is coming in leptos 0.7"
+                    );
+                    (quote! {}, false)
+                }
             };
             if is_static {
                 quote! {
diff --git a/leptos_macro/src/view/server_template.rs b/leptos_macro/src/view/server_template.rs
index 57e51ca635..c0d4ee552b 100644
--- a/leptos_macro/src/view/server_template.rs
+++ b/leptos_macro/src/view/server_template.rs
@@ -39,7 +39,22 @@ pub(crate) fn root_node_to_tokens_ssr(
             global_class,
             view_marker,
         ),
-        Node::Comment(_) | Node::Doctype(_) => quote! {},
+        Node::Comment(_) => {
+            proc_macro_error::emit_error!(
+                node,
+                "comment tags do not show up in rendered output\nsupport for \
+                 this is coming in leptos 0.7"
+            );
+            quote! {}
+        }
+        Node::Doctype(_) => {
+            proc_macro_error::emit_error!(
+                node,
+                "doctype tags do not show up in rendered output\nsupport for \
+                 this is coming in leptos 0.7"
+            );
+            quote! {}
+        }
         Node::Text(node) => {
             quote! {
                 ::leptos::leptos_dom::html::text(#node)
@@ -386,7 +401,22 @@ fn element_to_tokens_ssr(
                             Span::call_site(),
                             "You can't nest a fragment inside an element."
                         ),
-                        Node::Comment(_) | Node::Doctype(_) => {}
+                        Node::Comment(_) => {
+                            proc_macro_error::emit_error!(
+                                child,
+                                "comment tags do not show up in rendered \
+                                 output\nsupport for this is coming in leptos \
+                                 0.7"
+                            );
+                        }
+                        Node::Doctype(_) => {
+                            proc_macro_error::emit_error!(
+                                child,
+                                "doctype tags do not show up in rendered \
+                                 output\nsupport for this is coming in leptos \
+                                 0.7"
+                            );
+                        }
                     }
                 }
             }