Vendor dependencies

Let's see how I like this workflow.

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

@@ -0,0 +1,52 @@
+use js_sys::*;
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen_test]
+fn entries() {
+    let map = Map::new();
+    map.set(&"uno".into(), &1.into());
+
+    let entries = map.entries();
+
+    let next = entries.next().unwrap();
+    assert_eq!(next.done(), false);
+    assert!(next.value().is_object());
+    assert_eq!(Reflect::get(&next.value(), &0.into()).unwrap(), "uno");
+    assert_eq!(Reflect::get(&next.value(), &1.into()).unwrap(), 1);
+
+    let next = entries.next().unwrap();
+    assert!(next.done());
+    assert!(next.value().is_undefined());
+}
+
+#[wasm_bindgen_test]
+fn keys() {
+    let map = Map::new();
+    map.set(&"uno".into(), &1.into());
+
+    let keys = map.keys();
+
+    let next = keys.next().unwrap();
+    assert_eq!(next.done(), false);
+    assert_eq!(next.value(), "uno");
+
+    let next = keys.next().unwrap();
+    assert!(next.done());
+    assert!(next.value().is_undefined());
+}
+
+#[wasm_bindgen_test]
+fn values() {
+    let map = Map::new();
+    map.set(&"uno".into(), &1.into());
+
+    let values = map.values();
+
+    let next = values.next().unwrap();
+    assert_eq!(next.done(), false);
+    assert_eq!(next.value(), 1);
+
+    let next = values.next().unwrap();
+    assert!(next.done());
+    assert!(next.value().is_undefined());
+}