Move all Google endpoint URLs to a separate module

ext/src/endpoints.ts

@@ -0,0 +1,45 @@
+"use strict";
+
+/**
+ * Cast sender API loader script URL.
+ *
+ * Since the actual cast sender API script is hosted locally
+ * within Chrome, this script just acts a loader script for
+ * the real script whilst also doing some UA string
+ * checking.
+ */
+export const CAST_LOADER_SCRIPT_URL =
+        "https://www.gstatic.com/cv/js/sender/v1/cast_sender.js";
+
+/**
+ * Framework API loader script URL.
+ *
+ * Same URL as the usual loader script, but the additional
+ * search parameter is checked from within the script and
+ * the framework API script is conditionally loaded in
+ * addition to the regular API script.
+ */
+export const CAST_FRAMEWORK_LOADER_SCRIPT_URL =
+        `${CAST_LOADER_SCRIPT_URL}?loadCastFramework=1`;
+
+/**
+ * Cast API script URLs.
+ *
+ * Cast functionality in Chrome was previously provided by
+ * an extension. The cast API script is still provided via
+ * chrome-extension URLs for compatibility reasons.
+ */
+export const CAST_SCRIPT_URLS = [
+    "chrome-extension://pkedcjkdefgpdelpbcmbmeomcjbeemfm/cast_sender.js"
+  , "chrome-extension://enhhojjnijigcajfphajepfemndkmdlo/cast_sender.js"
+];
+
+/**
+ * Framework API script URL.
+ *
+ * Unlike the basic cast sender API, the framework API is
+ * not hosted locally within Chrome and is the only script
+ * fetched directly from Google servers.
+ */
+export const CAST_FRAMEWORK_SCRIPT_URL =
+        "https://www.gstatic.com/cast/sdk/libs/sender/1.0/cast_framework.js";

ext/src/main.ts

@@ -22,6 +22,9 @@ import { ReceiverStatusMessage
        , ServiceDownMessage
        , ServiceUpMessage } from "./messageTypes";
 
+import { CAST_FRAMEWORK_LOADER_SCRIPT_URL
+       , CAST_LOADER_SCRIPT_URL } from "./endpoints";
+
 
 const _ = browser.i18n.getMessage;
 
@@ -244,13 +247,6 @@ browser.menus.onShown.addListener(info => {
 });
 
 
-// Google-hosted API loader script
-const SENDER_SCRIPT_URL =
-        "https://www.gstatic.com/cv/js/sender/v1/cast_sender.js";
-
-const SENDER_SCRIPT_FRAMEWORK_URL =
-        `${SENDER_SCRIPT_URL}?loadCastFramework=1`;
-
 /**
  * Sender applications load a cast_sender.js script that
  * functions as a loader for the internal chrome-extension:
@@ -261,11 +257,9 @@ const SENDER_SCRIPT_FRAMEWORK_URL =
  */
 browser.webRequest.onBeforeRequest.addListener(
         async details => {
-
-            const isFramework = details.url === SENDER_SCRIPT_FRAMEWORK_URL;
-
             await browser.tabs.executeScript(details.tabId, {
-                code: `window._isFramework = ${isFramework}`
+                code: `window._isFramework = ${
+                        details.url === CAST_FRAMEWORK_LOADER_SCRIPT_URL}`
               , frameId: details.frameId
               , runAt: "document_start"
             });
@@ -276,14 +270,13 @@ browser.webRequest.onBeforeRequest.addListener(
               , runAt: "document_start"
             });
 
-
             return {
                 redirectUrl: browser.runtime.getURL("shim/bundle.js")
             };
         }
       , { urls: [
-            SENDER_SCRIPT_URL
-          , SENDER_SCRIPT_FRAMEWORK_URL
+            CAST_LOADER_SCRIPT_URL
+          , CAST_FRAMEWORK_LOADER_SCRIPT_URL
         ]}
       , [ "blocking" ]);
 

ext/src/shim/cast/classes/SessionRequest.ts

@@ -1,7 +1,7 @@
 "use strict";
 
-import Timeout from "./Timeout";
 import { Capability } from "../enums";
+import Timeout from "./Timeout";
 
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.SessionRequest
@@ -15,5 +15,5 @@ export default class SessionRequest {
                 Capability.VIDEO_OUT
               , Capability.AUDIO_OUT ]
           , public requestSessionTimeout: number
-                    = (new Timeout).requestSession) {}
+                    = (new Timeout()).requestSession) {}
 }

ext/src/shim/cast/classes/Timeout.ts

@@ -2,9 +2,9 @@
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.Timeout
 export default class Timeout {
-    leaveSession = 3000;
-    requestSession = 60000;
-    sendCustomMessage = 3000;
-    setReceiverVolume = 3000;
-    stopSession = 3000;
+    public leaveSession = 3000;
+    public requestSession = 60000;
+    public sendCustomMessage = 3000;
+    public setReceiverVolume = 3000;
+    public stopSession = 3000;
 }

ext/src/shim/contentSetup.ts

@@ -1,20 +1,15 @@
 "use strict";
 
+import { CAST_LOADER_SCRIPT_URL
+       , CAST_SCRIPT_URLS } from "../endpoints";
+
+
 const _window = (window.wrappedJSObject as any);
 
 _window.chrome = cloneInto({}, window);
 _window.navigator.presentation = cloneInto({}, window);
 
 
-
-const EXT_SENDER_SCRIPT_URLS = [
-    "chrome-extension://pkedcjkdefgpdelpbcmbmeomcjbeemfm/cast_sender.js"
-  , "chrome-extension://enhhojjnijigcajfphajepfemndkmdlo/cast_sender.js"
-];
-
-const SENDER_SCRIPT_URL = "https://www.gstatic.com/cv/js/sender/v1/cast_sender.js";
-
-
 /**
  * Replace the src property setter on <script> elements to
  * intercept the new value.
@@ -34,8 +29,8 @@ Reflect.defineProperty(
   , get
 
   , set: exportFunction(function (value) {
-        if (EXT_SENDER_SCRIPT_URLS.includes(value)) {
-            return set.call(this, SENDER_SCRIPT_URL);
+        if (CAST_SCRIPT_URLS.includes(value)) {
+            return set.call(this, CAST_LOADER_SCRIPT_URL);
         }
 
         return set.call(this, value);

ext/src/shim/index.ts

@@ -2,6 +2,7 @@
 
 import * as cast from "./cast";
 
+import { CAST_FRAMEWORK_SCRIPT_URL } from "../endpoints";
 import { loadScript } from "../lib/utils";
 import { onMessage } from "./messageBridge";
 
@@ -12,12 +13,10 @@ if (!_window.chrome) {
     _window.chrome = {};
 }
 
+// Create page-accessible API object
 _window.chrome.cast = cast;
 
 
-const CAST_FRAMEWORK_SCRIPT_URL =
-        "https://www.gstatic.com/cast/sdk/libs/sender/1.0/cast_framework.js";
-
 let bridgeInfo: any;
 let isFramework = false;