Vendor dependencies

Let's see how I like this workflow.

vendor/js-sys/tests/wasm/SetIterator.rs

@@ -0,0 +1,41 @@
+use js_sys::*;
+use wasm_bindgen::prelude::*;
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen_test]
+fn entries() {
+    let s = Set::new(&JsValue::undefined());
+    s.add(&1.into());
+    let iter = s.entries();
+    let obj = iter.next().unwrap();
+    assert!(!obj.done());
+    let array = Array::from(&obj.value());
+    assert_eq!(array.length(), 2);
+    array.for_each(&mut |a, _, _| {
+        assert_eq!(a, 1);
+    });
+
+    assert!(iter.next().unwrap().done());
+}
+
+#[wasm_bindgen_test]
+fn keys() {
+    let s = Set::new(&JsValue::undefined());
+    s.add(&1.into());
+    let iter = s.keys();
+    let obj = iter.next().unwrap();
+    assert!(!obj.done());
+    assert_eq!(obj.value(), 1);
+    assert!(iter.next().unwrap().done());
+}
+
+#[wasm_bindgen_test]
+fn values() {
+    let s = Set::new(&JsValue::undefined());
+    s.add(&1.into());
+    let iter = s.values();
+    let obj = iter.next().unwrap();
+    assert!(!obj.done());
+    assert_eq!(obj.value(), 1);
+    assert!(iter.next().unwrap().done());
+}