feat(media): expose the MediaSession interface object

moli-renderer-v8/src/context_bootstrap/specs/registry.rs

@@ -560,6 +560,10 @@ const CONSTRUCTOR_SPECS_BEFORE_STREAMS: &[ConstructorSpec] = &[
         interface: web_api_interfaces::ClipboardItem::DESCRIPTOR,
         kind: ConstructorKind::ClipboardItem,
     },
+    ConstructorSpec {
+        interface: web_api_interfaces::MediaSession::DESCRIPTOR,
+        kind: ConstructorKind::Illegal,
+    },
     ConstructorSpec {
         interface: web_api_interfaces::MediaCapabilities::DESCRIPTOR,
         kind: ConstructorKind::Illegal,

moli-renderer-v8/src/script_vm/tests/media_session_interfaces.rs

@@ -0,0 +1,44 @@
+use super::*;
+
+#[test]
+fn media_session_interfaces_preserve_native_inheritance_and_realm_contracts() {
+    for url in [
+        "https://media-session-interfaces.test/",
+        "http://media-session-interfaces.test/",
+        "http://localhost/",
+    ] {
+        let mut vm = new_storage_page_task_executor_test_vm(url);
+        vm.eval("document.body.innerHTML = '<iframe id=child></iframe>'")
+            .unwrap();
+        assert_eq!(vm.eval(r#"(() => {
+  const assert = (ok, message) => { if (!ok) throw Error(message); };
+  {
+    const realms = [window, document.getElementById('child').contentWindow];
+    for (const w of realms) {
+      for (const [name, parentName] of [["MediaSession","Object"]]) {
+        if (false && !w.isSecureContext) {
+          assert(!(name in w), name + ' hidden in an insecure realm');
+          continue;
+        }
+        const C = w[name], parent = w[parentName];
+        assert(typeof C === 'function' && C.name === name && C.length === 0, name + ' interface object');
+        const descriptor = Object.getOwnPropertyDescriptor(w, name);
+        assert(descriptor.writable && descriptor.configurable && !descriptor.enumerable, name + ' global descriptor');
+        assert(Object.getPrototypeOf(C.prototype) === parent.prototype, name + ' prototype inheritance');
+        assert(Object.getPrototypeOf(C) === (parentName === 'Object' ? w.Function.prototype : parent), name + ' interface inheritance');
+        assert(C.prototype.constructor === C, name + ' prototype constructor');
+        const tag = Object.getOwnPropertyDescriptor(C.prototype, Symbol.toStringTag);
+        assert(tag.value === name && !tag.writable && !tag.enumerable && tag.configurable, name + ' tag');
+        for (const call of [() => C(), () => new C()]) {
+          let error;
+          try { call(); } catch (caught) { error = caught; }
+          assert(error instanceof w.TypeError, name + ' rejects direct construction in the callee realm');
+          if (w !== window) assert(!(error instanceof TypeError), name + ' foreign error realm');
+        }
+      }
+    }
+    return true;
+  }
+})()"#).unwrap(), "true", "{url}");
+    }
+}

moli-renderer-v8/src/script_vm/tests/mod.rs

@@ -2183,3 +2183,4 @@ mod intersection_target_order;
 mod observer_element_arguments;
 
 mod media_device_interfaces;
+mod media_session_interfaces;

moli-renderer-v8/src/web_api_interfaces.rs

@@ -294,6 +294,7 @@ interfaces! {
     MediaList;
     MediaQueryList: EventTarget;
     MediaQueryListEvent: Event;
+    MediaSession;
     MediaSource: EventTarget;
     MemoryInfo;
     MessageChannel;