From 4978b998fe3b421cb26b403e75a01d847895310e Mon Sep 17 00:00:00 2001
From: Tim Kurdov <tim.kurdov@gmail.com>
Date: Sat, 12 Oct 2024 13:30:13 +0100
Subject: [PATCH] Allow boolean & update error for byte literals in `html!`
 (#3441)

* made byte & boolean literals accepted by html

* improved error message, outruled byte-string to HTML conversion

* update tests
---
 packages/yew-macro/src/html_tree/html_node.rs | 16 +++++++++---
 packages/yew-macro/src/stringify.rs           | 26 ++++++++++++-------
 .../tests/html_macro/node-fail.stderr         | 18 +++----------
 .../yew-macro/tests/html_macro/node-pass.rs   |  8 +++---
 4 files changed, 37 insertions(+), 31 deletions(-)

diff --git a/packages/yew-macro/src/html_tree/html_node.rs b/packages/yew-macro/src/html_tree/html_node.rs
index 6b8022ba11a..06be31ccc46 100644
--- a/packages/yew-macro/src/html_tree/html_node.rs
+++ b/packages/yew-macro/src/html_tree/html_node.rs
@@ -17,9 +17,19 @@ pub enum HtmlNode {
 impl Parse for HtmlNode {
     fn parse(input: ParseStream) -> Result<Self> {
         let node = if HtmlNode::peek(input.cursor()).is_some() {
-            let lit: Lit = input.parse()?;
-            if matches!(lit, Lit::ByteStr(_) | Lit::Byte(_) | Lit::Verbatim(_)) {
-                return Err(syn::Error::new(lit.span(), "unsupported type"));
+            let lit = input.parse()?;
+            match lit {
+                Lit::ByteStr(lit) => {
+                    return Err(syn::Error::new(
+                        lit.span(),
+                        "byte-strings can't be converted to HTML text
+                         note: remove the `b` prefix or convert this to a `String`",
+                    ))
+                }
+                Lit::Verbatim(lit) => {
+                    return Err(syn::Error::new(lit.span(), "unsupported literal"))
+                }
+                _ => (),
             }
             HtmlNode::Literal(Box::new(lit))
         } else {
diff --git a/packages/yew-macro/src/stringify.rs b/packages/yew-macro/src/stringify.rs
index 4ea9d6483c4..75764266841 100644
--- a/packages/yew-macro/src/stringify.rs
+++ b/packages/yew-macro/src/stringify.rs
@@ -1,3 +1,6 @@
+use std::borrow::Cow;
+use std::mem::size_of;
+
 use proc_macro2::{Span, TokenStream};
 use quote::{quote_spanned, ToTokens};
 use syn::spanned::Spanned;
@@ -75,15 +78,19 @@ impl Stringify for LitStr {
         }
     }
 }
+
 impl Stringify for Lit {
     fn try_into_lit(&self) -> Option<LitStr> {
-        let s = match self {
+        let mut buf = [0; size_of::<char>()];
+        let s: Cow<'_, str> = match self {
             Lit::Str(v) => return v.try_into_lit(),
-            Lit::Char(v) => v.value().to_string(),
-            Lit::Int(v) => v.base10_digits().to_string(),
-            Lit::Float(v) => v.base10_digits().to_string(),
-            Lit::Bool(_) | Lit::ByteStr(_) | Lit::Byte(_) | Lit::Verbatim(_) => return None,
-            _ => unreachable!("unknown Lit"),
+            Lit::Char(v) => (&*v.value().encode_utf8(&mut buf)).into(),
+            Lit::Int(v) => v.base10_digits().into(),
+            Lit::Float(v) => v.base10_digits().into(),
+            Lit::Bool(v) => if v.value() { "true" } else { "false" }.into(),
+            Lit::Byte(v) => v.value().to_string().into(),
+            Lit::Verbatim(_) | Lit::ByteStr(_) => return None,
+            _ => unreachable!("unknown Lit {:?}", self),
         };
         Some(LitStr::new(&s, self.span()))
     }
@@ -91,10 +98,10 @@ impl Stringify for Lit {
     fn stringify(&self) -> TokenStream {
         self.try_into_lit()
             .as_ref()
-            .map(Stringify::stringify)
-            .unwrap_or_else(|| stringify_at_runtime(self))
+            .map_or_else(|| stringify_at_runtime(self), Stringify::stringify)
     }
 }
+
 impl Stringify for Expr {
     fn try_into_lit(&self) -> Option<LitStr> {
         if let Expr::Lit(v) = self {
@@ -107,7 +114,6 @@ impl Stringify for Expr {
     fn stringify(&self) -> TokenStream {
         self.try_into_lit()
             .as_ref()
-            .map(Stringify::stringify)
-            .unwrap_or_else(|| stringify_at_runtime(self))
+            .map_or_else(|| stringify_at_runtime(self), Stringify::stringify)
     }
 }
diff --git a/packages/yew-macro/tests/html_macro/node-fail.stderr b/packages/yew-macro/tests/html_macro/node-fail.stderr
index fc94b419875..05676a5c9be 100644
--- a/packages/yew-macro/tests/html_macro/node-fail.stderr
+++ b/packages/yew-macro/tests/html_macro/node-fail.stderr
@@ -10,25 +10,15 @@ error: unexpected token, expected `}`
 5 |     html! { <span>{ "valid" "invalid" }</span> };
   |                             ^^^^^^^^^
 
-error: unsupported type
-  --> tests/html_macro/node-fail.rs:10:14
-   |
-10 |     html! {  b'a' };
-   |              ^^^^
-
-error: unsupported type
+error: byte-strings can't be converted to HTML text
+                                note: remove the `b` prefix or convert this to a `String`
   --> tests/html_macro/node-fail.rs:11:14
    |
 11 |     html! {  b"str" };
    |              ^^^^^^
 
-error: unsupported type
-  --> tests/html_macro/node-fail.rs:12:22
-   |
-12 |     html! {  <span>{ b'a' }</span> };
-   |                      ^^^^
-
-error: unsupported type
+error: byte-strings can't be converted to HTML text
+                                note: remove the `b` prefix or convert this to a `String`
   --> tests/html_macro/node-fail.rs:13:22
    |
 13 |     html! {  <span>{ b"str" }</span> };
diff --git a/packages/yew-macro/tests/html_macro/node-pass.rs b/packages/yew-macro/tests/html_macro/node-pass.rs
index ed38c3e77cf..38aad870ad3 100644
--- a/packages/yew-macro/tests/html_macro/node-pass.rs
+++ b/packages/yew-macro/tests/html_macro/node-pass.rs
@@ -37,12 +37,12 @@ pub struct u8;
 pub struct usize;
 
 fn main() {
-    _ = ::yew::html! { "" };
+    _ = ::yew::html! { b'b' };
     _ = ::yew::html! { 'a' };
     _ = ::yew::html! { "hello" };
-    _ = ::yew::html! { "42" };
-    _ = ::yew::html! { "1.234" };
-    _ = ::yew::html! { "true" };
+    _ = ::yew::html! { 42 };
+    _ = ::yew::html! { 1.234 };
+    _ = ::yew::html! { true };
 
     _ = ::yew::html! { <span>{ "" }</span> };
     _ = ::yew::html! { <span>{ 'a' }</span> };