feat: add initial support for guest-types command

crates/js-component-bindgen-component/src/lib.rs

@@ -75,6 +75,7 @@ impl Guest for JsComponentBindgenComponent {
             no_namespaced_exports: options.no_namespaced_exports.unwrap_or(false),
             multi_memory: options.multi_memory.unwrap_or(false),
             import_bindings: options.import_bindings.map(Into::into),
+            guest: options.guest.unwrap_or(false),
         };
 
         let js_component_bindgen::Transpiled {
@@ -160,6 +161,7 @@ impl Guest for JsComponentBindgenComponent {
             no_namespaced_exports: false,
             multi_memory: false,
             import_bindings: None,
+            guest: opts.guest.unwrap_or(false),
         };
 
         let files = generate_types(name, resolve, world, opts).map_err(|e| e.to_string())?;

crates/js-component-bindgen-component/wit/js-component-bindgen.wit

@@ -58,6 +58,9 @@ world js-component-bindgen {
     /// Whether to generate namespaced exports like `foo as "local:package/foo"`.
     /// These exports can break typescript builds.
     no-namespaced-exports: option<bool>,
+
+    /// Whether to generate module declarations like `declare module "local:package/foo" {...`.
+    guest: option<bool>,
 
     /// Whether to output core Wasm utilizing multi-memory or to polyfill
     /// this handling.
@@ -91,6 +94,8 @@ world js-component-bindgen {
     map: option<maps>,
     /// Features that should be enabled as part of feature gating
     features: option<enabled-feature-set>,
+    /// Whether to generate module declarations like `declare module "local:package/foo" {...`.
+    guest: option<bool>,
   }
 
   enum export-type {

crates/js-component-bindgen/src/transpile_bindgen.rs

@@ -68,6 +68,8 @@ pub struct TranspileOpts {
     /// Whether to output core Wasm utilizing multi-memory or to polyfill
     /// this handling.
     pub multi_memory: bool,
+    /// Whether to generate types for a guest module using module declarations.
+    pub guest: bool,
 }
 
 #[derive(Default, Clone, Debug)]

crates/js-component-bindgen/src/ts_bindgen.rs

@@ -29,6 +29,9 @@ struct TsBindgen {
     import_object: Source,
     /// TypeScript definitions which will become the export object
     export_object: Source,
+
+    /// Whether or not the types should be generated for a guest module
+    guest: bool,
 }
 
 /// Used to generate a `*.d.ts` file for each imported and exported interface for
@@ -59,6 +62,7 @@ pub fn ts_bindgen(
         local_names: LocalNames::default(),
         import_object: Source::default(),
         export_object: Source::default(),
+        guest: opts.guest,
     };
 
     let world = &resolve.worlds[id];
@@ -520,9 +524,15 @@ impl TsBindgen {
             return local_name;
         }
 
+        let module_or_namespace = if self.guest {
+            format!("declare module '{id_name}' {{")
+        } else {
+            format!("export namespace {camel} {{")
+        };
+
         let mut gen = self.ts_interface(resolve, false);
 
-        uwriteln!(gen.src, "export namespace {camel} {{");
+        uwriteln!(gen.src, "{module_or_namespace}");
         for (_, func) in resolve.interfaces[id].functions.iter() {
             // Ensure that the function  the world item for stability guarantees and exclude if they do not match
             if !feature_gate_allowed(resolve, package, &func.stability, &func.name)

examples/components/add/package.json

@@ -9,7 +9,7 @@
     "all": "npm run build && npm run transpile && npm run transpiled-js"
   },
   "devDependencies": {
-    "@bytecodealliance/jco": "1.7.1",
-    "@bytecodealliance/componentize-js": "0.13.1"
+    "@bytecodealliance/jco": "1.8.1",
+    "@bytecodealliance/componentize-js": "0.15.0"
   }
 }

examples/components/http-hello-world/.gitignore

@@ -0,0 +1,4 @@
+node_modules
+dist
+*.wasm
+pnpm-lock.yaml

examples/components/http-hello-world/.nvmrc

@@ -0,0 +1 @@
+v22.5.1