Vendor things

third-party/vendor/js-sys/tests/wasm/Promise.rs

@@ -0,0 +1,11 @@
+use js_sys::*;
+use wasm_bindgen::JsCast;
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen_test]
+fn promise_inheritance() {
+    let promise = Promise::new(&mut |_, _| ());
+    assert!(promise.is_instance_of::<Promise>());
+    assert!(promise.is_instance_of::<Object>());
+    let _: &Object = promise.as_ref();
+}