webidl: add support for named constructors

crates/webidl/src/lib.rs

@@ -182,10 +182,10 @@ impl<'a> WebidlParse<&'a webidl::ast::NonPartialInterface> for webidl::ast::Exte
         program: &mut backend::ast::Program,
         interface: &'a webidl::ast::NonPartialInterface,
     ) -> Result<()> {
-        let mut add_constructor = |arguments: &[webidl::ast::Argument]| {
+        let mut add_constructor = |arguments: &[webidl::ast::Argument], class: &str| {
             let self_ty = ident_ty(rust_ident(&interface.name));
             let kind = backend::ast::ImportFunctionKind::JsConstructor {
-                class: interface.name.to_string(),
+                class: class.to_string(),
                 ty: self_ty.clone(),
             };
             create_function(
@@ -211,12 +211,22 @@ impl<'a> WebidlParse<&'a webidl::ast::NonPartialInterface> for webidl::ast::Exte
                 webidl::ast::ArgumentListExtendedAttribute { arguments, name },
             ) if name == "Constructor" =>
             {
-                add_constructor(&*arguments);
+                add_constructor(arguments, &interface.name);
             }
             webidl::ast::ExtendedAttribute::NoArguments(webidl::ast::Other::Identifier(name))
                 if name == "Constructor" =>
             {
-                add_constructor(&[] as &[_]);
+                add_constructor(&[] as &[_], &interface.name);
+            }
+            webidl::ast::ExtendedAttribute::NamedArgumentList(
+                webidl::ast::NamedArgumentListExtendedAttribute {
+                    lhs_name,
+                    rhs_arguments,
+                    rhs_name,
+                },
+            ) if lhs_name == "NamedConstructor" =>
+            {
+                add_constructor(rhs_arguments, rhs_name);
             }
             webidl::ast::ExtendedAttribute::ArgumentList(_)
             | webidl::ast::ExtendedAttribute::Identifier(_)

tests/all/webidl/simple.rs

@@ -118,3 +118,61 @@ fn property() {
         )
         .test();
 }
+
+#[test]
+fn named_constructor() {
+    project()
+        .file(
+            "foo.webidl",
+            r#"
+            [NamedConstructor=Bar(double value)]
+            interface Foo {
+                [Pure]
+                readonly attribute double value;
+            };
+        "#,
+        )
+        .file(
+            // Not a perfect test, but it gets the job done.
+            "foo.ts",
+            r#"
+            export class Foo {
+                protected _value: number = 0;
+                get value(): number {
+                    return this._value;
+                }
+            }
+
+            export class Bar extends Foo {
+                constructor(_value: number) {
+                    super();
+                    this._value = _value;
+                }
+            }
+            "#,
+        )
+        .file(
+            "src/lib.rs",
+            r#"
+            #![feature(proc_macro, wasm_custom_section, wasm_import_module)]
+
+            extern crate wasm_bindgen;
+
+            use wasm_bindgen::prelude::*;
+
+            pub mod foo;
+
+            use foo::Foo;
+
+            #[wasm_bindgen]
+            pub fn test() {
+                let x = Foo::new(3.14159);
+                let tmp = x.value() == 3.14159;
+                assert!(tmp);
+                let tmp = x.value() != 0.;
+                assert!(tmp);
+            }
+        "#,
+        )
+        .test();
+}