Add support for empty enum variants and enum variants that start with a digit

crates/backend/src/util.rs

@@ -30,6 +30,8 @@ pub fn rust_ident(name: &str) -> Ident {
         panic!("tried to create empty Ident (from \"\")");
     } else if is_rust_keyword(name) {
         Ident::new(&format!("{}_", name), proc_macro2::Span::call_site())
+    } else if name.chars().next().unwrap().is_ascii_digit() {
+        Ident::new(&format!("N{}", name), proc_macro2::Span::call_site())
     } else {
         raw_ident(name)
     }

crates/web-sys/webidls/unavailable_enum_ident/README.md

@@ -1 +0,0 @@
-These WebIDL files have enum variants that are not valid rust Idents, for example "2x", or "".

crates/webidl/src/lib.rs

@@ -720,7 +720,13 @@ impl<'a> WebidlParse<()> for webidl::ast::Enum {
                 variants: self
                     .variants
                     .iter()
-                    .map(|v| rust_ident(camel_case_ident(&v).as_str()))
+                    .map(|v|
+                        if !v.is_empty() {
+                            rust_ident(camel_case_ident(&v).as_str())
+                        } else {
+                            rust_ident("None")
+                        }
+                    )
                     .collect(),
                 variant_values: self.variants.clone(),
                 rust_attrs: vec![parse_quote!(#[derive(Copy, Clone, PartialEq, Debug)])],