Return an error if there are two enums with the same name

CHANGELOG.md

@@ -112,6 +112,9 @@
   enhancing type safety and compatibility.
   [#3647](https://github.com/rustwasm/wasm-bindgen/pull/3647)
 
+* Throw an error on enum name collisions, previously only one enum would be emitted.
+  [#3669](https://github.com/rustwasm/wasm-bindgen/pull/3669)
+
 ### Fixed
 
 * Fixed `wasm_bindgen` macro to handle raw identifiers in field names.

crates/cli-support/src/js/mod.rs

@@ -2455,7 +2455,7 @@ impl<'a> Context<'a> {
         pairs.sort_by_key(|(k, _)| *k);
         check_duplicated_getter_and_setter_names(&pairs)?;
 
-        for e in self.aux.enums.iter() {
+        for (_, e) in self.aux.enums.iter() {
             self.generate_enum(e)?;
         }
 

crates/cli-support/src/wit/mod.rs

@@ -852,8 +852,15 @@ impl<'a> Context<'a> {
                 .collect(),
             generate_typescript: enum_.generate_typescript,
         };
-        self.aux.enums.push(aux);
-        Ok(())
+        let mut result = Ok(());
+        self.aux
+            .enums
+            .entry(aux.name.clone())
+            .and_modify(|existing| {
+                result = Err(anyhow!("duplicate enums:\n{:?}\n{:?}", existing, aux));
+            })
+            .or_insert(aux);
+        result
     }
 
     fn struct_(&mut self, struct_: decode::Struct<'_>) -> Result<(), Error> {

crates/cli-support/src/wit/nonstandard.rs

@@ -41,7 +41,7 @@ pub struct WasmBindgenAux {
 
     /// Auxiliary information to go into JS/TypeScript bindings describing the
     /// exported enums from Rust.
-    pub enums: Vec<AuxEnum>,
+    pub enums: HashMap<String, AuxEnum>,
 
     /// Auxiliary information to go into JS/TypeScript bindings describing the
     /// exported structs from Rust and their fields they've got exported.

tests/wasm/node.js

@@ -24,14 +24,14 @@ exports.test_works = function() {
   assert.strictEqual(r2.add(2), 13);
   r2.free();
 
-  assert.strictEqual(wasm.Color.Green, 0);
-  assert.strictEqual(wasm.Color.Yellow, 1);
-  assert.strictEqual(wasm.Color.Red, 2);
-  assert.strictEqual(wasm.Color[0], 'Green');
-  assert.strictEqual(wasm.Color[1], 'Yellow');
-  assert.strictEqual(wasm.Color[2], 'Red');
-  assert.strictEqual(Object.keys(wasm.Color).length, 6);
-  assert.strictEqual(wasm.cycle(wasm.Color.Green), wasm.Color.Yellow);
+  assert.strictEqual(wasm.NodeColor.Green, 0);
+  assert.strictEqual(wasm.NodeColor.Yellow, 1);
+  assert.strictEqual(wasm.NodeColor.Red, 2);
+  assert.strictEqual(wasm.NodeColor[0], 'Green');
+  assert.strictEqual(wasm.NodeColor[1], 'Yellow');
+  assert.strictEqual(wasm.NodeColor[2], 'Red');
+  assert.strictEqual(Object.keys(wasm.NodeColor).length, 6);
+  assert.strictEqual(wasm.cycle(wasm.NodeColor.Green), wasm.NodeColor.Yellow);
 
   wasm.node_math(1.0, 2.0);
 };

tests/wasm/node.rs

@@ -34,18 +34,19 @@ impl Foo {
     }
 }
 
+// Use a different name to avoid a collision with the `Color` enum in enums.rs when --no-modules is used.
 #[wasm_bindgen]
-pub enum Color {
+pub enum NodeColor {
     Green,
     Yellow,
     Red,
 }
 #[wasm_bindgen]
-pub fn cycle(color: Color) -> Color {
+pub fn cycle(color: NodeColor) -> NodeColor {
     match color {
-        Color::Green => Color::Yellow,
-        Color::Yellow => Color::Red,
-        Color::Red => Color::Green,
+        NodeColor::Green => NodeColor::Yellow,
+        NodeColor::Yellow => NodeColor::Red,
+        NodeColor::Red => NodeColor::Green,
     }
 }