Add support for importing default exports

.travis.yml

@@ -120,6 +120,11 @@ matrix:
         - if [ "$TRAVIS_PULL_REQUEST" = "false" ]; then aws s3 sync ~/$TRAVIS_BUILD_NUMBER s3://wasm-bindgen-ci/$TRAVIS_BUILD_NUMBER; fi
       if: branch = master
 
+    # The `cli-support` crate's tests pass
+    - name: "test cli-support crate"
+      script: cargo test -p wasm-bindgen-cli-support
+      if: branch = master
+
     # The `web-sys` crate's tests pass
     - name: "test web-sys crate"
       install:

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

@@ -1858,7 +1858,7 @@ impl<'a> Context<'a> {
         let class = self.import_identifier(name);
         let op = match &method_data.kind {
             decode::MethodKind::Constructor => {
-                return Ok(ImportTarget::Constructor(class.to_string()))
+                return Ok(ImportTarget::Constructor(class.to_string()));
             }
             decode::MethodKind::Operation(op) => op,
         };
@@ -2649,7 +2649,9 @@ impl<'a> Import<'a> {
 fn generate_identifier(name: &str, used_names: &mut HashMap<String, usize>) -> String {
     let cnt = used_names.entry(name.to_string()).or_insert(0);
     *cnt += 1;
-    if *cnt == 1 {
+    // We want to mangle `default` at once, so we can support default exports and don't generate
+    // invalid glue code like this: `import { default } from './module';`.
+    if *cnt == 1 && name != "default" {
         name.to_string()
     } else {
         format!("{}{}", name, cnt)
@@ -2668,3 +2670,24 @@ fn format_doc_comments(comments: &[&str], js_doc_comments: Option<String>) -> St
     };
     format!("/**\n{}{}*/\n", body, doc)
 }
+
+#[test]
+fn test_generate_identifier() {
+    let mut used_names: HashMap<String, usize> = HashMap::new();
+    assert_eq!(
+        generate_identifier("someVar", &mut used_names),
+        "someVar".to_string()
+    );
+    assert_eq!(
+        generate_identifier("someVar", &mut used_names),
+        "someVar2".to_string()
+    );
+    assert_eq!(
+        generate_identifier("default", &mut used_names),
+        "default1".to_string()
+    );
+    assert_eq!(
+        generate_identifier("default", &mut used_names),
+        "default2".to_string()
+    );
+}

tests/wasm/import_class.js

@@ -30,15 +30,18 @@ class Construct {
 Construct.internal_string = '';
 exports.Construct = Construct;
 
-exports.NewConstructors = class {
+class NewConstructor {
   constructor(field) {
     this.field = field;
   }
 
   get() {
     return this.field + 1;
   }
-};
+}
+
+exports.NewConstructors = NewConstructor;
+exports.default = NewConstructor;
 
 let switch_called = false;
 class SwitchMethods {

tests/wasm/import_class.rs

@@ -29,6 +29,13 @@ extern "C" {
     #[wasm_bindgen(method)]
     fn get(this: &NewConstructors) -> i32;
 
+    #[wasm_bindgen(js_name = default)]
+    type RenamedTypes;
+    #[wasm_bindgen(constructor, js_class = default)]
+    fn new(arg: i32) -> RenamedTypes;
+    #[wasm_bindgen(method, js_class = default)]
+    fn get(this: &RenamedTypes) -> i32;
+
     fn switch_methods_a();
     fn switch_methods_b();
     type SwitchMethods;
@@ -125,6 +132,12 @@ fn new_constructors() {
     assert_eq!(f.get(), 2);
 }
 
+#[wasm_bindgen_test]
+fn rename_type() {
+    let f = RenamedTypes::new(1);
+    assert_eq!(f.get(), 2);
+}
+
 #[wasm_bindgen_test]
 fn switch_methods() {
     assert!(!switch_methods_called());