From 0caf72d5bd1bb9b60d38d51b037065a7386fa3d9 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 1 Jan 2021 14:21:47 +0100
Subject: [PATCH] Convert `FirefoxCom` to a class, with `static` methods

*Please note:* It's highly recommended to ignore whitespace-only changes when looking at this patch.

Besides modernizing this code, by converting it to a standard class, the existing JSDoc comments are updated to actually agree better with the way that this functionality is used now. (The next patch will reduce usage of `FirefoxCom.request` significantly, hence the JSDocs for the optional `callback` is removed to not unnecessarily advertise that functionality.)

Finally, the unnecessary/unused `return` statement at the end of `FirefoxCom.request` is also removed.
---
 web/firefoxcom.js | 112 ++++++++++++++++++++++------------------------
 1 file changed, 54 insertions(+), 58 deletions(-)

diff --git a/web/firefoxcom.js b/web/firefoxcom.js
index ecb3095d7..6ab1f70cc 100644
--- a/web/firefoxcom.js
+++ b/web/firefoxcom.js
@@ -25,69 +25,65 @@ if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("MOZCENTRAL")) {
   );
 }
 
-const FirefoxCom = (function FirefoxComClosure() {
-  return {
-    /**
-     * Creates an event that the extension is listening for and will
-     * synchronously respond to.
-     * NOTE: It is reccomended to use request() instead since one day we may not
-     * be able to synchronously reply.
-     * @param {string} action - The action to trigger.
-     * @param {string} [data] - The data to send.
-     * @returns {*} The response.
-     */
-    requestSync(action, data) {
-      const request = document.createTextNode("");
-      document.documentElement.appendChild(request);
+class FirefoxCom {
+  /**
+   * Creates an event that the extension is listening for and will
+   * synchronously respond to.
+   * NOTE: It is recommended to use request() instead since one day we may not
+   * be able to synchronously reply.
+   * @param {string} action - The action to trigger.
+   * @param {Object|string} [data] - The data to send.
+   * @returns {*} The response.
+   */
+  static requestSync(action, data) {
+    const request = document.createTextNode("");
+    document.documentElement.appendChild(request);
 
-      const sender = document.createEvent("CustomEvent");
-      sender.initCustomEvent("pdf.js.message", true, false, {
-        action,
-        data,
-        sync: true,
-      });
-      request.dispatchEvent(sender);
-      const response = sender.detail.response;
-      request.remove();
+    const sender = document.createEvent("CustomEvent");
+    sender.initCustomEvent("pdf.js.message", true, false, {
+      action,
+      data,
+      sync: true,
+    });
+    request.dispatchEvent(sender);
+    const response = sender.detail.response;
+    request.remove();
 
-      return response;
-    },
+    return response;
+  }
 
-    /**
-     * Creates an event that the extension is listening for and will
-     * asynchronously respond by calling the callback.
-     * @param {string} action - The action to trigger.
-     * @param {string} [data] - The data to send.
-     * @param {Function} [callback] - Response callback that will be called
-     *   with one data argument.
-     */
-    request(action, data, callback) {
-      const request = document.createTextNode("");
-      if (callback) {
-        request.addEventListener(
-          "pdf.js.response",
-          event => {
-            const response = event.detail.response;
-            event.target.remove();
+  /**
+   * Creates an event that the extension is listening for and will, optionally,
+   * asynchronously respond to.
+   * @param {string} action - The action to trigger.
+   * @param {Object|string} [data] - The data to send.
+   */
+  static request(action, data, callback = null) {
+    const request = document.createTextNode("");
+    if (callback) {
+      request.addEventListener(
+        "pdf.js.response",
+        event => {
+          const response = event.detail.response;
+          event.target.remove();
 
-            callback(response);
-          },
-          { once: true }
-        );
-      }
-      document.documentElement.appendChild(request);
+          callback(response);
+        },
+        { once: true }
+      );
+    }
+    document.documentElement.appendChild(request);
 
-      const sender = document.createEvent("CustomEvent");
-      sender.initCustomEvent("pdf.js.message", true, false, {
-        action,
-        data,
-        sync: false,
-        responseExpected: !!callback,
-      });
-      return request.dispatchEvent(sender);
-    },
-  };
-})();
+    const sender = document.createEvent("CustomEvent");
+    sender.initCustomEvent("pdf.js.message", true, false, {
+      action,
+      data,
+      sync: false,
+      responseExpected: !!callback,
+    });
+    request.dispatchEvent(sender);
+  }
+}
 
 class DownloadManager {
   downloadUrl(url, filename) {