Vendor dependencies

Let's see how I like this workflow.

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

@@ -0,0 +1,61 @@
+use js_sys::*;
+use wasm_bindgen::prelude::*;
+use wasm_bindgen::JsCast;
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen]
+extern "C" {
+    type SomeKey;
+    #[wasm_bindgen(method, setter, structural)]
+    fn set_some(this: &SomeKey, val: JsValue);
+}
+
+fn some_key() -> Object {
+    let key = SomeKey::from(JsValue::from(Object::new()));
+    key.set_some("key".into());
+    Object::from(JsValue::from(key))
+}
+
+#[wasm_bindgen_test]
+fn new() {
+    assert!(JsValue::from(WeakMap::new()).is_object());
+}
+
+#[wasm_bindgen_test]
+fn get_and_set() {
+    let map = WeakMap::new();
+    let key = some_key();
+    map.set(&key, &"value".into());
+    assert_eq!(map.get(&key), "value");
+    assert_eq!(map.get(&Object::new()), JsValue::undefined());
+    assert_eq!(map.get(&some_key()), JsValue::undefined());
+}
+
+#[wasm_bindgen_test]
+fn has() {
+    let map = WeakMap::new();
+    let key = some_key();
+    map.set(&key, &"value".into());
+    assert!(map.has(&key));
+    assert!(!map.has(&Object::new()));
+    assert!(!map.has(&some_key()));
+}
+
+#[wasm_bindgen_test]
+fn delete() {
+    let map = WeakMap::new();
+    let key = some_key();
+    assert!(!map.has(&key));
+    map.set(&key, &"value".into());
+    assert!(map.has(&key));
+    map.delete(&key);
+    assert!(!map.has(&key));
+}
+
+#[wasm_bindgen_test]
+fn weakmap_inheritance() {
+    let map = WeakMap::new();
+    assert!(map.is_instance_of::<WeakMap>());
+    assert!(map.is_instance_of::<Object>());
+    let _: &Object = map.as_ref();
+}