Migrate port-util.js to TypeScript

src/shared/messaging/port-util.js → src/shared/messaging/port-util.ts

+export type Frame = 'guest' | 'host' | 'notebook' | 'profile' | 'sidebar';
+
 /**
  * Message sent by `PortProvider` and `PortFinder` to establish a
  * MessageChannel-based connection between two frames.
- *
- * @typedef {'guest'|'host'|'notebook'|'profile'|'sidebar'} Frame
- *
- * @typedef Message
- * @prop {Frame} frame1 - Role of the source frame
- * @prop {Frame} frame2 - Role of the target frame
- * @prop {'offer'|'request'} type - Message type. "request" messages are sent
- *   by the source frame to the host frame to request a connection. "offer"
- *   messages are sent from the host frame back to the source frame and also
- *   to the target frame, accompanied by a MessagePort.
- * @prop {string} requestId - ID of the request. Used to associate "offer"
- *   messages with their corresponding "request" messages.
- * @prop {string} [sourceId] - Identifier for the source frame. This is useful
- *   in cases where multiple source frames with a given role may connect to
- *   the same destination frame.
  */
+export type Message = {
+  /** Role of the source frame. */
+  frame1: Frame;
+
+  /** Role of the target frame. */
+  frame2: Frame;
+
+  /**
+   * Message type. "request" messages are sent by the source frame to the host
+   * frame to request a connection. "offer" messages are sent from the host
+   * frame back to the source frame and also to the target frame, accompanied by
+   * a MessagePort.
+   */
+  type: 'offer' | 'request';
+
+  /**
+   * ID of the request. Used to associate "offer" messages with their
+   * corresponding "request" messages.
+   */
+  requestId: string;
+
+  /**
+   * Identifier for the source frame. This is useful in cases where multiple
+   * source frames with a given role may connect to the same destination frame.
+   */
+  sourceId?: string;
+};
 
 /**
- * Return true if an object, eg. from the data field of a `MessageEvent`, is a
+ * Return true if an object, eg. from the `data` field of a `MessageEvent`, is a
  * valid `Message`.
- *
- * @param {any} data
- * @return {data is Message}
  */
-export function isMessage(data) {
+export function isMessage(data: any): data is Message {
   if (data === null || typeof data !== 'object') {
     return false;
   }
 
-  for (let property of ['frame1', 'frame2', 'type', 'requestId']) {
+  for (const property of ['frame1', 'frame2', 'type', 'requestId']) {
     if (typeof data[property] !== 'string') {
       return false;
     }
@@ -41,11 +52,8 @@ export function isMessage(data) {
 
 /**
  * Return true if the data payload from a MessageEvent matches `message`.
- *
- * @param {any} data
- * @param {Partial<Message>} message
  */
-export function isMessageEqual(data, message) {
+export function isMessageEqual(data: any, message: Partial<Message>) {
   if (!isMessage(data)) {
     return false;
   }
@@ -60,11 +68,10 @@ export function isMessageEqual(data, message) {
 
 /**
  * Check that source is of type Window.
- *
- * @param {MessageEventSource|null} source
- * @return {source is Window}
  */
-export function isSourceWindow(source) {
+export function isSourceWindow(
+  source: MessageEventSource | null
+): source is Window {
   if (
     // `source` can be of type Window, MessagePort, ServiceWorker, or null.
     // `source instanceof Window` doesn't work in Chrome if `source` is a