From 40e7443ca097f4cc2ad84dc5200f23ba5cd05ea4 Mon Sep 17 00:00:00 2001
From: Luke Curley <kixelated@gmail.com>
Date: Thu, 17 Apr 2025 18:00:50 -0700
Subject: [PATCH] Add support for unnamed tuples.

---
 web-message-derive/src/lib.rs | 52 +++++++++++++++++++++++++++++++----
 web-message/src/derive.rs     | 36 ++++++------------------
 web-message/src/error.rs      |  3 ++
 3 files changed, 58 insertions(+), 33 deletions(-)

diff --git a/web-message-derive/src/lib.rs b/web-message-derive/src/lib.rs
index e2f5e98..00947ea 100644
--- a/web-message-derive/src/lib.rs
+++ b/web-message-derive/src/lib.rs
@@ -75,11 +75,12 @@ fn expand_enum(
 				});
 
 				Some(quote! {
-					#variant_str => {
+					#variant_str if val.is_object() => {
 						Ok(#enum_ident::#variant_ident {
 							#(#field_assignments),*
 						})
 					}
+					#variant_str => Err(::web_message::Error::UnexpectedType),
 				})
 			}
 
@@ -89,10 +90,30 @@ fn expand_enum(
 				Some(quote! {
 					#variant_str => Ok(#enum_ident::#variant_ident(::web_message::Message::from_message(val)?)),
 				})
-			}
+			},
+
+			Fields::Unnamed(fields_unnamed) => {
+				let fields_count = fields_unnamed.unnamed.len() as u32;
+				let field_assignments = (0..fields_count).map(|i| {
+					quote! {
+						::web_message::Message::from_message(arr.get(#i))
+							.map_err(|_| ::web_message::Error::InvalidField(stringify!(#i)))?
+					}
+				});
+
+				Some(quote! {
+					#variant_str if val.is_array() => {
+						let arr = ::web_sys::js_sys::Array::from(&val);
+						if arr.length() != #fields_count {
+							return Err(::web_message::Error::UnexpectedLength);
+						}
 
-			Fields::Unnamed(_) => {
-				unimplemented!("web-message does not support multi-element tuple variants (yet?)");
+						Ok(#enum_ident::#variant_ident (
+							#(#field_assignments),*
+						))
+					}
+					#variant_str => Err(::web_message::Error::UnexpectedType),
+				})
 			}
 		}
 	});
@@ -151,7 +172,28 @@ fn expand_enum(
 					}
 				}
 			}
-			Fields::Unnamed(_) => unimplemented!("web-message does not support tuple variants (yet)"),
+			Fields::Unnamed(fields_unnamed) => {
+				let fields_count = fields_unnamed.unnamed.len();
+				let field_idents: Vec<_> = (0..fields_count)
+					.map(|i| syn::Ident::new(&format!("field_{}", i), proc_macro2::Span::call_site()))
+					.collect();
+
+				let set_fields = field_idents.iter().map(|f| {
+					quote! {
+						inner.push(&#f.into_message(_transferable));
+					}
+				});
+
+				quote! {
+					#enum_ident::#variant_ident(#(#field_idents),*) => {
+						let obj = ::web_sys::js_sys::Object::new();
+						let inner = ::web_sys::js_sys::Array::new();
+						#(#set_fields)*
+						::web_sys::js_sys::Reflect::set(&obj, &#variant_str.into(), &inner.into()).unwrap();
+						obj.into()
+					}
+				}
+			}
 		}
 	});
 
diff --git a/web-message/src/derive.rs b/web-message/src/derive.rs
index f0d3055..64f0437 100644
--- a/web-message/src/derive.rs
+++ b/web-message/src/derive.rs
@@ -8,11 +8,19 @@ mod test {
 
 	#[test]
 	fn enum_msg() {
+		#[derive(Message, Clone, Debug, PartialEq, Eq)]
+		struct Config {
+			width: u32,
+			height: u32,
+		}
+
 		#[derive(Message, Clone, Debug, PartialEq, Eq)]
 		enum Command {
 			Connect { url: String },
 			Frame { name: Option<String>, payload: ArrayBuffer },
+			Config(Config),
 			Close,
+			Dimensions(u32, u64),
 		}
 
 		let command = Command::Frame {
@@ -50,32 +58,4 @@ mod test {
 		assert_eq!(event, out);
 		assert_eq!(transferable, [event.payload].iter().collect());
 	}
-
-	#[test]
-	fn enum_variant() {
-		#[derive(Message, Clone, Debug, PartialEq, Eq)]
-		struct Config {
-			width: u32,
-			height: u32,
-		}
-
-		#[derive(Message, Clone, Debug, PartialEq, Eq)]
-		enum Command {
-			Connect { url: String },
-			Config(Config),
-			Close,
-		}
-
-		let command = Command::Config(Config {
-			width: 100,
-			height: 100,
-		});
-
-		let mut transferable = Array::new();
-		let obj = command.clone().into_message(&mut transferable);
-		let out = Command::from_message(obj).unwrap();
-
-		assert_eq!(command, out);
-		assert_eq!(transferable.length(), 1);
-	}
 }
diff --git a/web-message/src/error.rs b/web-message/src/error.rs
index e593877..3c2c582 100644
--- a/web-message/src/error.rs
+++ b/web-message/src/error.rs
@@ -6,6 +6,9 @@ pub enum Error {
 	#[error("invalid '{0}' field")]
 	InvalidField(&'static str),
 
+	#[error("unexpected length")]
+	UnexpectedLength,
+
 	#[error("unexpected type")]
 	UnexpectedType,