Merge pull request #626 from alexcrichton/optional-arg

Add support for `Option<&T>` in imported argument lists

crates/cli-support/src/js/rust2js.rs

@@ -125,6 +125,10 @@ impl<'a, 'b> Rust2Js<'a, 'b> {
             self.cx.expose_take_object();
             self.js_arguments.push(format!("takeObject({})", abi));
             return Ok(())
+        } else if arg.is_ref_anyref() {
+            self.cx.expose_get_object();
+            self.js_arguments.push(format!("getObject({})", abi));
+            return Ok(())
         }
 
         if optional {
@@ -253,10 +257,6 @@ impl<'a, 'b> Rust2Js<'a, 'b> {
             ref d if d.is_number() => abi,
             Descriptor::Boolean => format!("{} !== 0", abi),
             Descriptor::Char => format!("String.fromCodePoint({})", abi),
-            ref d if d.is_ref_anyref() => {
-                self.cx.expose_get_object();
-                format!("getObject({})", abi)
-            }
             _ => bail!(
                 "unimplemented argument type in imported function: {:?}",
                 arg

tests/wasm/main.rs

@@ -5,3 +5,4 @@ extern crate wasm_bindgen_test;
 extern crate wasm_bindgen;
 
 pub mod api;
+pub mod option;

tests/wasm/option.js

@@ -0,0 +1,29 @@
+const assert = require('assert');
+const wasm = require('wasm-bindgen-test.js');
+
+class MyType {}
+
+exports.MyType = MyType;
+
+exports.take_none_byval = function(x) {
+  assert.strictEqual(x, undefined);
+};
+exports.take_some_byval = function(x) {
+  assert.ok(x !== null && x !== undefined);
+  assert.ok(x instanceof MyType);
+};
+exports.return_undef_byval = function() { return undefined; };
+exports.return_null_byval = function() { return null; };
+exports.return_some_byval = function(x) {
+  return new MyType();
+};
+
+exports.test_option_values = function() {
+  wasm.rust_take_none_byval(null);
+  wasm.rust_take_none_byval(undefined);
+  wasm.rust_take_some_byval(new MyType());
+  assert.strictEqual(wasm.rust_return_none_byval(), undefined);
+  const x = wasm.rust_return_some_byval();
+  assert.ok(x !== null && x !== undefined);
+  assert.ok(x instanceof MyType);
+};

tests/wasm/option.rs

@@ -0,0 +1,61 @@
+use wasm_bindgen_test::*;
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen(module = "tests/wasm/option.js", version = "*")]
+extern {
+    pub type MyType;
+    #[wasm_bindgen(constructor)]
+    fn new() -> MyType;
+
+    fn take_none_byval(t: Option<MyType>);
+    fn take_some_byval(t: Option<MyType>);
+    fn return_undef_byval() -> Option<MyType>;
+    fn return_null_byval() -> Option<MyType>;
+    fn return_some_byval() -> Option<MyType>;
+    fn test_option_values();
+
+    #[wasm_bindgen(js_name = take_none_byval)]
+    fn take_none_byref(t: Option<&MyType>);
+    #[wasm_bindgen(js_name = take_some_byval)]
+    fn take_some_byref(t: Option<&MyType>);
+}
+
+#[wasm_bindgen_test]
+fn import_by_value() {
+    take_none_byval(None);
+    take_some_byval(Some(MyType::new()));
+    assert!(return_null_byval().is_none());
+    assert!(return_undef_byval().is_none());
+    assert!(return_some_byval().is_some());
+}
+
+#[wasm_bindgen_test]
+fn export_by_value() {
+    test_option_values();
+}
+
+#[wasm_bindgen]
+pub fn rust_take_none_byval(t: Option<MyType>) {
+    assert!(t.is_none());
+}
+
+#[wasm_bindgen]
+pub fn rust_take_some_byval(t: Option<MyType>) {
+    assert!(t.is_some());
+}
+
+#[wasm_bindgen]
+pub fn rust_return_none_byval() -> Option<MyType> {
+    None
+}
+
+#[wasm_bindgen]
+pub fn rust_return_some_byval() -> Option<MyType> {
+    Some(MyType::new())
+}
+
+#[wasm_bindgen_test]
+fn import_by_ref() {
+    take_none_byref(None);
+    take_some_byref(Some(&MyType::new()));
+}