Port WeakSet tests to wasm

crates/js-sys/tests/wasm/WeakSet.rs

@@ -0,0 +1,42 @@
+use wasm_bindgen::prelude::*;
+use wasm_bindgen_test::*;
+use js_sys::*;
+
+#[wasm_bindgen]
+extern {
+    type SomeValue;
+    #[wasm_bindgen(method, setter, structural)]
+    fn set_some(this: &SomeValue, val: JsValue);
+}
+
+fn some_value() -> Object {
+    let value = SomeValue::from(JsValue::from(Object::new()));
+    value.set_some("value".into());
+    Object::from(JsValue::from(value))
+}
+
+#[wasm_bindgen_test]
+fn new() {
+    assert!(JsValue::from(WeakSet::new()).is_object())
+}
+
+#[wasm_bindgen_test]
+fn has() {
+    let set = WeakSet::new();
+    let value = some_value();
+    assert!(!set.has(&value));
+    set.add(&value);
+    assert!(set.has(&value));
+    assert!(!set.has(&some_value()));
+}
+
+#[wasm_bindgen_test]
+fn delete() {
+    let set = WeakSet::new();
+    let value = some_value();
+    set.add(&value);
+    assert!(set.has(&value));
+    assert!(set.delete(&value));
+    assert!(!set.has(&value));
+    assert!(!set.delete(&value));
+}