Enable strict mode for extension build

app/tsconfig.json

@@ -4,7 +4,4 @@
         "./src/**/*"
       , "./@types/**/*"
     ]
-  , "compilerOptions": {
-        "strict": true
-    }
 }

ext/src/background/ShimManager.ts

@@ -2,6 +2,7 @@
 
 import bridge from "../lib/bridge";
 import loadSender from "../lib/loadSender";
+import logger from "../lib/logger";
 import options from "../lib/options";
 
 import { Message } from "../types";
@@ -87,6 +88,11 @@ export default new class ShimManager {
     private async createShimFromContent (
             contentPort: browser.runtime.Port): Promise<Shim> {
 
+        if (contentPort.sender?.tab?.id === undefined
+         || contentPort.sender?.frameId === undefined) {
+            throw logger.error("Content shim created with an invalid port context.");
+        }
+
         /**
          * If there's already an active shim for the sender
          * tab/frame ID, disconnect it.
@@ -135,6 +141,11 @@ export default new class ShimManager {
     }
 
     private async handleContentMessage (shim: Shim, message: Message) {
+        if (shim.contentTabId === undefined
+         || shim.contentFrameId === undefined) {
+            throw logger.error("Shim associated with content sender missing tab/frame ID");
+        }
+        
         const [ destination ] = message.subject.split(":/");
         if (destination === "bridge") {
             shim.bridgePort.postMessage(message);

ext/src/background/StatusManager.ts

@@ -1,6 +1,7 @@
 "use strict";
 
 import bridge from "../lib/bridge";
+import logger from "../lib/logger";
 
 import { TypedEventTarget } from "../lib/typedEvents";
 import { Message, Receiver, ReceiverStatus } from "../types";
@@ -38,7 +39,7 @@ interface EventMap {
 export default new class StatusManager
         extends TypedEventTarget<EventMap> {
 
-    private bridgePort: browser.runtime.Port;
+    private bridgePort: (browser.runtime.Port | null) = null;
     private receivers = new Map<string, Receiver>();
 
     constructor () {
@@ -131,6 +132,10 @@ export default new class StatusManager
 
                 const receiver = this.receivers.get(id);
 
+                if (!receiver) {
+                    throw logger.error(`Could not find receiver (${id}) specified in status message.`);
+                }
+
                 // Merge with existing
                 this.receivers.set(id, {
                     ...receiver

ext/src/background/background.ts

@@ -2,6 +2,7 @@
 
 import defaultOptions from "../defaultOptions";
 import loadSender from "../lib/loadSender";
+import logger from "../lib/logger";
 import options from "../lib/options";
 
 import { getChromeUserAgent } from "../lib/userAgents";
@@ -67,6 +68,10 @@ function initBrowserAction () {
      * top-level frame.
      */
     browser.browserAction.onClicked.addListener(async tab => {
+        if (tab.id === undefined) {
+            throw logger.error("Tab ID not found in browser action handler.");
+        }
+
         const selection = await ReceiverSelectorManager.getSelection(tab.id);
 
         if (selection) {
@@ -140,6 +145,10 @@ async function initMenus () {
     browser.menus.onClicked.addListener(async (info, tab) => {
         if (info.parentMenuItemId === menuIdWhitelist) {
             const pattern = whitelistChildMenuPatterns.get(info.menuItemId);
+            if (!pattern) {
+                throw logger.error(`Whitelist pattern not found for menu item ID ${info.menuItemId}.`);
+            }
+
             const whitelist = await options.get("userAgentWhitelist");
 
             // Add to whitelist and update options
@@ -150,6 +159,17 @@ async function initMenus () {
         }
 
 
+        if (tab?.id === undefined) {
+            throw logger.error("Menu handler tab ID not found.");
+        }
+        if (info.frameId === undefined) {
+            throw logger.error("Menu handler frame ID not found.");
+        }
+        if (!info.pageUrl) {
+            throw logger.error("Menu handler page URL not found.");
+        }
+
+
         const availableMediaTypes = getMediaTypesForPageUrl(info.pageUrl);
 
         switch (info.menuItemId) {
@@ -157,6 +177,11 @@ async function initMenus () {
                 const selection = await ReceiverSelectorManager.getSelection(
                         tab.id, info.frameId);
 
+                // Selection cancelled
+                if (!selection) {
+                    break;
+                }
+
                 loadSender({
                     tabId: tab.id
                   , frameId: info.frameId
@@ -447,6 +472,10 @@ function initWhitelist () {
         const { os } = await browser.runtime.getPlatformInfo();
         const chromeUserAgent = getChromeUserAgent(os);
 
+        if (!details.requestHeaders) {
+            throw logger.error("OnBeforeSendHeaders handler details missing requestHeaders.");
+        }
+
         const host = details.requestHeaders.find(
                 header => header.name === "Host");
 
@@ -457,7 +486,7 @@ function initWhitelist () {
                  * so pretend to be an old version of Chrome to get the old
                  * site.
                  */
-                if (host.value === "www.youtube.com") {
+                if (host?.value === "www.youtube.com") {
                     header.value = getChromeUserAgent(os, true);
                     break;
                 }

ext/src/background/receiverSelector/NativeReceiverSelector.ts

@@ -33,7 +33,7 @@ export default class NativeReceiverSelector
         extends TypedEventTarget<ReceiverSelectorEvents>
         implements ReceiverSelector {
 
-    private bridgePort: browser.runtime.Port;
+    private bridgePort: (browser.runtime.Port | null) = null;
     private wasReceiverSelected: boolean = false;
     private _isOpen: boolean = false;
 

ext/src/background/receiverSelector/PopupReceiverSelector.ts

@@ -4,10 +4,11 @@ import ReceiverSelector, {
         ReceiverSelectorEvents
       , ReceiverSelectorMediaType } from "./ReceiverSelector";
 
+import logger from "../../lib/logger";
 import options from "../../lib/options";
 
 import { TypedEventTarget } from "../../lib/typedEvents";
-import { getWindowCenteredProps } from "../../lib/utils";
+import { getWindowCenteredProps, WindowCenteredProps } from "../../lib/utils";
 import { Message, Receiver } from "../../types";
 
 
@@ -15,19 +16,19 @@ export default class PopupReceiverSelector
         extends TypedEventTarget<ReceiverSelectorEvents>
         implements ReceiverSelector {
 
-    private windowId: number;
+    private windowId?: number;
 
-    private messagePort: browser.runtime.Port;
-    private messagePortDisconnected: boolean;
+    private messagePort?: browser.runtime.Port;
+    private messagePortDisconnected?: boolean;
 
-    private receivers: Receiver[];
-    private defaultMediaType: ReceiverSelectorMediaType;
-    private availableMediaTypes: ReceiverSelectorMediaType;
+    private receivers?: Receiver[];
+    private defaultMediaType?: ReceiverSelectorMediaType;
+    private availableMediaTypes?: ReceiverSelectorMediaType;
 
     private wasReceiverSelected: boolean = false;
 
     private _isOpen: boolean = false;
-    private requestedAppId: string;
+    private requestedAppId?: string;
 
 
     constructor () {
@@ -97,9 +98,22 @@ export default class PopupReceiverSelector
         this.defaultMediaType = defaultMediaType;
         this.availableMediaTypes = availableMediaTypes;
 
-        // Calculate centered size/position based on current window
-        const centeredProps = getWindowCenteredProps(
-                await browser.windows.getCurrent(), 350, 200);
+
+        let centeredProps: WindowCenteredProps = {
+            left: 100
+          , top: 100
+          , width: 350
+          , height: 200
+        };
+
+        try {
+            // Calculate centered size/position based on current window
+            centeredProps = getWindowCenteredProps(
+                    await browser.windows.getCurrent()
+                  , centeredProps.width, centeredProps.height);
+        } catch {
+            // Shouldn't ever hit this, but defaults are provided in case
+        }
 
         const popup = await browser.windows.create({
             url: "ui/popup/index.html"
@@ -107,6 +121,10 @@ export default class PopupReceiverSelector
           , ...centeredProps
         });
 
+        if (popup?.id === undefined) {
+            throw logger.error("Failed to create receiver selector popup.");
+        }
+
         this._isOpen = true;
         this.windowId = popup.id;
 
@@ -132,7 +150,7 @@ export default class PopupReceiverSelector
         }
 
         this._isOpen = false;
-        this.requestedAppId = null;
+        this.requestedAppId = undefined;
 
         if (this.messagePort && !this.messagePortDisconnected) {
             this.messagePort.disconnect();
@@ -183,10 +201,11 @@ export default class PopupReceiverSelector
         }
 
         // Cleanup
-        this.windowId = null;
-        this.messagePort = null;
-        this.receivers = null;
-        this.defaultMediaType = null;
+        this.windowId = undefined;
+        this.messagePort = undefined;
+        this.receivers = undefined;
+        this.defaultMediaType = undefined;
+        this.availableMediaTypes = undefined;
         this.wasReceiverSelected = false;
     }
 
@@ -203,7 +222,9 @@ export default class PopupReceiverSelector
             browser.windows.onFocusChanged.removeListener(
                     this.onWindowsFocusChanged);
 
-            browser.windows.remove(this.windowId);
+            if (this.windowId) {
+                browser.windows.remove(this.windowId);
+            }
         }
     }
 }

ext/src/background/receiverSelector/ReceiverSelectorManager.ts

@@ -1,6 +1,7 @@
 "use strict";
 
 import options from "../../lib/options";
+import logger from "../../lib/logger";
 
 import ShimManager from "../ShimManager";
 import StatusManager from "../StatusManager";
@@ -38,7 +39,11 @@ let sharedSelector: ReceiverSelector;
 
 async function getSelector () {
     if (!sharedSelector) {
-        sharedSelector = await createSelector();
+        try {
+            sharedSelector = await createSelector();
+        } catch (err) {
+            throw logger.error("Failed to create receiver selector.");
+        }
     }
 
     return sharedSelector;
@@ -59,7 +64,7 @@ async function getSelection (
         contextTabId: number
       , contextFrameId = 0
       , withMediaSender = false)
-        : Promise<ReceiverSelection> {
+        : Promise<ReceiverSelection | null> {
 
     return new Promise(async (resolve, reject) => {
         let currentShim = ShimManager.getShim(
@@ -71,7 +76,7 @@ async function getSelection (
          */
         if (currentShim?.requestedAppId ===
                 await options.get("mirroringAppId")) {
-            currentShim = null;
+            currentShim = undefined;
         }
 
         let defaultMediaType = ReceiverSelectorMediaType.Tab;
@@ -164,8 +169,7 @@ async function getSelection (
                 Array.from(StatusManager.getReceivers())
               , defaultMediaType
               , availableMediaTypes
-              , currentShim?.requestedAppId
-                      ?? (withMediaSender && DEFAULT_MEDIA_RECEIVER_APP_ID));
+              , currentShim?.requestedAppId ?? DEFAULT_MEDIA_RECEIVER_APP_ID);
     });
 }
 

ext/src/lib/bridge.ts

@@ -2,6 +2,7 @@
 
 import semver from "semver";
 
+import logger from "./logger";
 import nativeMessaging from "./nativeMessaging";
 import options from "./options";
 
@@ -13,7 +14,7 @@ async function connect (): Promise<browser.runtime.Port> {
     bridgePort.onDisconnect.addListener(() => {
         if (bridgePort.error) {
             console.error(`${applicationName} disconnected:`
-                  , this.bridgePort.error.message);
+                  , bridgePort.error.message);
         } else {
             console.info(`${applicationName} disconnected`);
         }
@@ -35,6 +36,10 @@ export interface BridgeInfo {
 
 async function getInfo (): Promise<BridgeInfo> {
     const applicationName = await options.get("bridgeApplicationName");
+    if (!applicationName) {
+        throw logger.error("Bridge application name not found.");
+    }
+
     let applicationVersion: string;
 
     try {
@@ -45,7 +50,7 @@ async function getInfo (): Promise<BridgeInfo> {
               , { subject: "bridge:/getInfo"
                 , data: version });
     } catch (err) {
-        return null;
+        throw logger.error("Failed to connect to bridge application");
     }
 
     /**

ext/src/lib/loadSender.ts

@@ -1,5 +1,6 @@
 "use strict";
 
+import logger from "./logger";
 import { stringify } from "./utils";
 
 import { ReceiverSelection
@@ -27,6 +28,11 @@ export default async function loadSender (opts: LoadSenderOptions) {
     switch (opts.selection.mediaType) {
         case ReceiverSelectorMediaType.App: {
             const shim = ShimManager.getShim(opts.tabId, opts.frameId);
+            if (!shim) {
+                throw logger.error(`Shim not found at tabId ${
+                        opts.tabId} / frameId ${opts.frameId}`)
+            }
+
             shim.contentPort.postMessage({
                 subject: "shim:/launchApp"
               , data: { receiver: opts.selection.receiver }

ext/src/lib/logger.ts

@@ -0,0 +1,19 @@
+"use strict";
+
+export class Logger {
+    constructor (private prefix: string) {}
+
+    log (message: string) {
+        console.log(`${this.prefix} (Log): ${message}`);
+    }
+    debug (message: string) {
+        console.debug(`${this.prefix} (Debug): ${message}`);
+    }
+    error (message: string) {
+        const formattedMessage = `${this.prefix} (Error): ${message}`;
+        console.error(formattedMessage);
+        return new Error(formattedMessage);
+    }
+}
+
+export default new Logger("fx_cast");

ext/src/lib/nativeMessaging.ts

@@ -116,7 +116,7 @@ function connectNative (application: string) {
 
             socket.addEventListener("close", ev => {
                 if (ev.code !== 1000) {
-                    this.error = {
+                    portObject.error = {
                         // TODO: Set a proper error message
                         message: ""
                     };

ext/src/lib/options.ts

@@ -2,6 +2,8 @@
 
 import defaultOptions from "../defaultOptions";
 
+import logger from "./logger";
+
 import { ReceiverSelectorType } from "../background/receiverSelector";
 import { TypedEventTarget } from "./typedEvents";
 import { TypedStorageArea } from "./typedStorage";
@@ -116,6 +118,8 @@ export default new class extends TypedEventTarget<EventMap> {
 
         if (options.hasOwnProperty(name)) {
             return options[name];
+        } else {
+            throw logger.error(`Failed to find option ${name} in storage.`);
         }
     }
 
@@ -139,20 +143,16 @@ export default new class extends TypedEventTarget<EventMap> {
      * storage are set. Does not override any existing options.
      */
     public async update (defaults = defaultOptions): Promise<void> {
-        const oldOpts = await this.getAll();
-        const newOpts: Partial<Options> = {};
+        const newOpts = await this.getAll();
 
         // Find options not already in storage
         for (const [ optName, optVal ] of Object.entries(defaults)) {
-            if (!oldOpts.hasOwnProperty(optName)) {
+            if (!newOpts.hasOwnProperty(optName)) {
                 newOpts[optName] = optVal;
             }
         }
 
         // Update storage with default values of new options
-        return this.setAll({
-            ...oldOpts
-          , ...newOpts
-        });
+        return this.setAll(newOpts);
     }
 };

ext/src/lib/typedEvents.ts

@@ -5,13 +5,17 @@ export interface TypedEvents {
 }
 
 export class TypedEventTarget<T extends TypedEvents> extends EventTarget {
+    // @ts-ignore
     public addEventListener<K extends keyof T> (
             type: K, listener: (ev: CustomEvent<T[K]>) => void): void {
+        // @ts-ignore
         super.addEventListener(type as string, listener);
     }
 
+    // @ts-ignore
     public removeEventListener<K extends keyof T> (
             type: K, listener: (ev: CustomEvent<T[K]>) => void): void {
+        // @ts-ignore
         super.removeEventListener(type as string, listener);
     }
 

ext/src/lib/userAgents.ts

@@ -11,7 +11,7 @@ const UA_CHROME_LEGACY = "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.288
 const UA_SAFARI = "AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0 Safari/605.1.15";
 
 
-function getPlatformComponent (platform: string): string {
+function getPlatformComponent (platform: string): string | undefined {
     switch (platform) {
         case "mac": return PLATFORM_MAC; break;
         case "win": return PLATFORM_WIN; break;

ext/src/lib/utils.ts

@@ -1,5 +1,7 @@
 "use strict";
 
+import logger from "./logger";
+
 import { ReceiverSelectorMediaType } from "../background/receiverSelector";
 
 
@@ -10,6 +12,8 @@ export function getNextEllipsis (ellipsis: string): string {
     if (ellipsis === "..") return "...";
     if (ellipsis === "...") return "";
     /* tslint:enable:curly */
+
+    return "";
 }
 
 /**
@@ -79,7 +83,7 @@ export function getMediaTypesForPageUrl (
 }
 
 
-interface WindowCenteredProps {
+export interface WindowCenteredProps {
     width: number;
     height: number;
     left: number;
@@ -91,6 +95,11 @@ export function getWindowCenteredProps (
       , width: number
       , height: number): WindowCenteredProps {
 
+    if (refWin.left === undefined || refWin.width === undefined
+     || refWin.top === undefined || refWin.height === undefined) {
+        throw logger.error("refWin missing positional attributes.");
+    }
+
     const centerX = refWin.left + (refWin.width / 2);
     const centerY = refWin.top + (refWin.height / 3);
 

ext/src/senders/media/index.ts

@@ -1,5 +1,6 @@
 "use strict";
 
+import logger from "../../lib/logger";
 import options from "../../lib/options";
 import cast, { ensureInit } from "../../shim/export";
 
@@ -8,7 +9,7 @@ import { Message, Receiver } from "../../types";
 
 function getLocalAddress () {
     const pc = new RTCPeerConnection();
-    pc.createDataChannel(null);
+    pc.createDataChannel("");
     pc.createOffer().then(pc.setLocalDescription.bind(pc));
 
     return new Promise((resolve, reject) => {
@@ -90,6 +91,9 @@ function getSession (opts: InitOptions): Promise<cast.Session> {
             }
         }
 
+        // TODO: Handle this
+        function sessionListener () {}
+
         function onRequestSessionSuccess (session: cast.Session) {
             resolve(session);
         }
@@ -103,7 +107,7 @@ function getSession (opts: InitOptions): Promise<cast.Session> {
 
         const apiConfig = new cast.ApiConfig(
                 sessionRequest
-              , null               // sessionListener
+              , sessionListener    // sessionListener
               , receiverListener); // receiverListener
 
 
@@ -112,7 +116,7 @@ function getSession (opts: InitOptions): Promise<cast.Session> {
 }
 
 function getMedia (opts: InitOptions): Promise<cast.media.Media> {
-    return new Promise(async resolve => {
+    return new Promise(async (resolve, reject) => {
         let mediaUrl = new URL(opts.mediaUrl);
         let subtitleUrls: URL[] = [];
 
@@ -137,14 +141,13 @@ function getMedia (opts: InitOptions): Promise<cast.media.Media> {
                         path => new URL(path, baseUrl));
 
             } catch (err) {
-                console.error("Failed to start media server");
-                return;
+                throw logger.error("Failed to start media server");
             }
         }
 
 
         const activeTrackIds: number[] = [];
-        const mediaInfo = new cast.media.MediaInfo(mediaUrl.href, null);
+        const mediaInfo = new cast.media.MediaInfo(mediaUrl.href, "");
 
         mediaInfo.metadata = new cast.media.GenericMediaMetadata();
         mediaInfo.metadata.metadataType = cast.media.MetadataType.GENERIC;
@@ -222,7 +225,7 @@ function getMedia (opts: InitOptions): Promise<cast.media.Media> {
                     }
 
                     // Add track to mediaInfo
-                    mediaInfo.tracks.push(castTrack);
+                    mediaInfo.tracks?.push(castTrack);
 
                     // If enabled, mark as active track for load request
                     if (track.mode === "showing" || trackElement.default) {
@@ -238,9 +241,7 @@ function getMedia (opts: InitOptions): Promise<cast.media.Media> {
         loadRequest.autoplay = false;
         loadRequest.activeTrackIds = activeTrackIds;
 
-        currentSession.loadMedia(loadRequest
-              , (media) => resolve(media)
-              , null);
+        currentSession.loadMedia(loadRequest, resolve, reject);
     });
 }
 
@@ -266,11 +267,11 @@ async function registerMediaElementListeners () {
 
 
         mediaElement.addEventListener("play", () => {
-            currentMedia.play(null, null, null);
+            currentMedia.play();
         });
 
         mediaElement.addEventListener("pause", () => {
-            currentMedia.pause(null, null, null);
+            currentMedia.pause();
         });
 
         mediaElement.addEventListener("suspend", () => {
@@ -281,7 +282,7 @@ async function registerMediaElementListeners () {
             const seekRequest = new cast.media.SeekRequest();
             seekRequest.currentTime = mediaElement.currentTime;
 
-            currentMedia.seek(seekRequest, null, null);
+            currentMedia.seek(seekRequest);
         });
 
         mediaElement.addEventListener("ratechange", () => {
@@ -394,7 +395,7 @@ export async function init (opts: InitOptions) {
             });
 
             if (await options.get("mediaStopOnUnload")) {
-                currentSession.stop(null, null);
+                currentSession.stop(() => {}, () => {});
             }
         });
     }

ext/src/senders/media/overlay/overlayContent.ts

@@ -202,11 +202,11 @@ class AudioPlayerElement extends PlayerElement {}
 class VideoPlayerElement extends PlayerElement {
     set overlayHidden (val: boolean) {
         const shadowRoot = internalShadowRoots.get(this);
-        (shadowRoot.querySelector(".overlay") as HTMLDivElement).hidden = val;
+        (shadowRoot?.querySelector(".overlay") as HTMLDivElement).hidden = val;
     }
     get overlayHidden () {
         const shadowRoot = internalShadowRoots.get(this);
-        return (shadowRoot.querySelector(".overlay") as HTMLDivElement).hidden;
+        return (shadowRoot?.querySelector(".overlay") as HTMLDivElement).hidden;
     }
 }
 

ext/src/senders/mirroring.ts

@@ -35,7 +35,7 @@ function sendAppMessage (subject: string, data: any) {
     session.sendMessage(FX_CAST_RECEIVER_APP_NAMESPACE, {
         subject
       , data
-    }, null, null);
+    }, () => {}, () => {});
 }
 
 
@@ -76,6 +76,11 @@ async function onRequestSessionSuccess (newSession: cast.Session) {
             const canvas = document.createElement("canvas");
             const ctx = canvas.getContext("2d");
 
+            // Shouldn't be possible
+            if (!ctx) {
+                break;
+            }
+
             // Set initial size
             canvas.width = window.innerWidth;
             canvas.height = window.innerHeight;

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

@@ -4,6 +4,6 @@
 export default class DialRequest {
     constructor (
             public appName: string
-          , public launchParameter: string = null) {
+          , public launchParameter: (string | null) = null) {
     }
 }

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

@@ -4,7 +4,7 @@
 export default class Error {
     constructor (
             public code: string
-          , public description: string = null
+          , public description: (string | null) = null
           , public details: any = null) {
     }
 }

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

@@ -2,8 +2,8 @@
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.Image
 export default class Image {
-    public width: number = null;
-    public height: number = null;
+    public width: (number | null) = null;
+    public height: (number | null) = null;
 
     constructor (public url: string) {}
 }

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

@@ -8,14 +8,14 @@ import { ReceiverType } from "../enums";
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.Receiver
 export default class Receiver {
-    public displayStatus: ReceiverDisplayStatus = null;
-    public isActiveInput: boolean = null;
+    public displayStatus: (ReceiverDisplayStatus | null) = null;
+    public isActiveInput: (boolean | null) = null;
     public receiverType: string = ReceiverType.CAST;
 
     constructor (
             public label: string
           , public friendlyName: string
           , public capabilities: string[] = []
-          , public volume: Volume = null) {
+          , public volume: (Volume | null) = null) {
     }
 }

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

@@ -5,7 +5,7 @@ import Image from "./Image";
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.ReceiverDisplayStatus
 export default class ReceiverDisplayStatus {
-    public showStop: boolean = null;
+    public showStop: (boolean | null) = null;
 
     constructor (
             public statusText: string

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

@@ -2,8 +2,8 @@
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.SenderApplication
 export default class SenderApplication {
-    public packageId: string = null;
-    public url: string = null;
+    public packageId: (string | null) = null;
+    public url: (string | null) = null;
 
     constructor (public platform: string) {}
 }

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

@@ -50,7 +50,7 @@ export default class Session {
     public namespaces: Array<{ name: "string" }>;
     public senderApps: SenderApplication[];
     public status: SessionStatus;
-    public statusText: string;
+    public statusText: string | null;
     public transportId: string;
 
     constructor (
@@ -102,12 +102,15 @@ export default class Session {
             switch (message.subject) {
                 case "shim:/session/stopped": {
                     // Disconnect from extension messages
-                    _listener.get(this).disconnect();
+                    _listener.get(this)?.disconnect();
 
                     this.status = SessionStatus.STOPPED;
 
-                    for (const listener of _updateListeners.get(this)) {
-                        listener(false);
+                    const updateListeners = _updateListeners.get(this);
+                    if (updateListeners) {
+                        for (const listener of updateListeners) {
+                            listener(false);
+                        }
                     }
 
                     break;
@@ -147,8 +150,11 @@ export default class Session {
                         }
                     }
 
-                    for (const listener of _updateListeners.get(this)) {
-                        listener(true);
+                    const updateListeners = _updateListeners.get(this);
+                    if (updateListeners) {
+                        for (const listener of updateListeners) {
+                            listener(true);
+                        }
                     }
 
                     break;
@@ -156,19 +162,28 @@ export default class Session {
 
 
                 case "shim:/session/impl_addMessageListener": {
-                    const { namespace, data } = message.data;
-                    for (const listener of
-                            _messageListeners.get(this).get(namespace)) {
-                        listener(namespace, data);
+                    const { namespace, data }
+                        : { namespace: string, data: string } = message.data;
+
+                    const messageListeners = _messageListeners
+                            .get(this)?.get(namespace);
+
+                    if (messageListeners) {
+                        for (const listener of messageListeners) {
+                            listener(namespace, data);
+                        }
                     }
 
                     break;
                 }
 
                 case "shim:/session/impl_sendMessage": {
-                    const { messageId, error } = message.data;
-                    const [ successCallback, errorCallback ]
-                            = _sendMessageCallbacks.get(this).get(messageId);
+                    const { messageId, error }
+                        : { messageId: string, error: boolean } = message.data;
+
+                    const [ successCallback, errorCallback ] =
+                            _sendMessageCallbacks
+                                .get(this)?.get(messageId) ?? [];
 
                     if (error && errorCallback) {
                         errorCallback(new _Error(ErrorCode.SESSION_ERROR));
@@ -176,17 +191,16 @@ export default class Session {
                         successCallback();
                     }
 
-                    _sendMessageCallbacks.get(this).delete(messageId);
+                    _sendMessageCallbacks.get(this)?.delete(messageId);
 
                     break;
                 }
 
                 case "shim:/session/impl_setReceiverMuted": {
                     const { volumeId, error } = message.data;
-                    const [ successCallback, errorCallback ]
-                            = _setReceiverMutedCallbacks
-                                .get(this)
-                                .get(volumeId);
+                    const [ successCallback, errorCallback ] =
+                            _setReceiverMutedCallbacks
+                                .get(this)?.get(volumeId) ?? [];
 
                     if (error && errorCallback) {
                         errorCallback(new _Error(ErrorCode.SESSION_ERROR));
@@ -194,16 +208,16 @@ export default class Session {
                         successCallback();
                     }
 
-                    _setReceiverMutedCallbacks.get(this).delete(volumeId);
+                    _setReceiverMutedCallbacks.get(this)?.delete(volumeId);
 
                     break;
                 }
 
                 case "shim:/session/impl_setReceiverVolumeLevel": {
                     const { volumeId, error } = message.data;
-                    const [ successCallback, errorCallback ]
-                            = _setReceiverVolumeLevelCallbacks.get(this)
-                                .get(volumeId);
+                    const [ successCallback, errorCallback ] =
+                            _setReceiverVolumeLevelCallbacks
+                                .get(this)?.get(volumeId) ?? [];
 
                     if (error && errorCallback) {
                         errorCallback(new _Error(ErrorCode.SESSION_ERROR));
@@ -211,7 +225,8 @@ export default class Session {
                         successCallback();
                     }
 
-                    _setReceiverVolumeLevelCallbacks.get(this).delete(volumeId);
+                    _setReceiverVolumeLevelCallbacks
+                        .get(this)?.delete(volumeId);
 
                     break;
                 }
@@ -219,18 +234,21 @@ export default class Session {
                 case "shim:/session/impl_stop": {
                     const { stopId, error } = message.data;
                     const [ successCallback, errorCallback ]
-                            = _stopCallbacks.get(this).get(stopId);
+                            = _stopCallbacks.get(this)?.get(stopId) ?? [];
 
                     // Disconnect from extension messages
-                    _listener.get(this).disconnect();
+                    _listener.get(this)?.disconnect();
 
                     if (error && errorCallback) {
                         errorCallback(new _Error(ErrorCode.SESSION_ERROR));
                     } else {
                         this.status = SessionStatus.STOPPED;
 
-                        for (const listener of _updateListeners.get(this)) {
-                            listener(false);
+                        const updateListeners = _updateListeners.get(this);
+                        if (updateListeners) {
+                            for (const listener of updateListeners) {
+                                listener(false);
+                            }
                         }
 
                         if (successCallback) {
@@ -238,7 +256,7 @@ export default class Session {
                         }
                     }
 
-                    _stopCallbacks.get(this).delete(stopId);
+                    _stopCallbacks.get(this)?.delete(stopId);
 
                     break;
                 }
@@ -257,11 +275,11 @@ export default class Session {
             namespace: string
           , listener: MessageListener) {
 
-        if (!_messageListeners.get(this).has(namespace)) {
-            _messageListeners.get(this).set(namespace, new Set());
+        if (!_messageListeners.get(this)?.has(namespace)) {
+            _messageListeners.get(this)?.set(namespace, new Set());
         }
 
-        _messageListeners.get(this).get(namespace).add(listener);
+        _messageListeners.get(this)?.get(namespace)?.add(listener);
 
         sendMessageResponse({
             subject: "bridge:/session/impl_addMessageListener"
@@ -271,7 +289,7 @@ export default class Session {
     }
 
     public addUpdateListener (listener: UpdateListener) {
-        _updateListeners.get(this).add(listener);
+        _updateListeners.get(this)?.add(listener);
     }
 
     public leave (
@@ -286,7 +304,7 @@ export default class Session {
           , _id: _id.get(this)
         });
 
-        _leaveCallbacks.get(this).set(id, [
+        _leaveCallbacks.get(this)?.set(id, [
             successCallback
           , errorCallback
         ]);
@@ -322,12 +340,17 @@ export default class Session {
             const message = JSON.parse(data);
 
             if (message.status && message.status.length > 0) {
+                const sessionId = _id.get(this);
+                if (!sessionId) {
+                    return;
+                }
+
                 hasResponded = true;
 
                 const media = new Media(
                         this.sessionId
                       , message.status[0].mediaSessionId
-                      , _id.get(this));
+                      , sessionId);
 
                 media.media = loadRequest.media;
                 this.media = [ media ];
@@ -361,14 +384,14 @@ export default class Session {
             namespace: string
           , listener: MessageListener): void {
 
-        _messageListeners.get(this).get(namespace).delete(listener);
+        _messageListeners.get(this)?.get(namespace)?.delete(listener);
     }
 
     public removeUpdateListener (
             _namespace: string
           , listener: UpdateListener): void {
 
-        _updateListeners.get(this).delete(listener);
+        _updateListeners.get(this)?.delete(listener);
     }
 
     public sendMessage (
@@ -389,7 +412,7 @@ export default class Session {
           , _id: _id.get(this)
         });
 
-        _sendMessageCallbacks.get(this).set(messageId, [
+        _sendMessageCallbacks.get(this)?.set(messageId, [
             successCallback
           , errorCallback
         ]);
@@ -408,7 +431,7 @@ export default class Session {
           , _id: _id.get(this)
         });
 
-        _setReceiverMutedCallbacks.get(this).set(volumeId, [
+        _setReceiverMutedCallbacks.get(this)?.set(volumeId, [
             successCallback
           , errorCallback
         ]);
@@ -427,7 +450,7 @@ export default class Session {
           , _id: _id.get(this)
         });
 
-        _setReceiverVolumeLevelCallbacks.get(this).set(volumeId, [
+        _setReceiverVolumeLevelCallbacks.get(this)?.set(volumeId, [
             successCallback
           , errorCallback
         ]);
@@ -445,7 +468,7 @@ export default class Session {
           , _id: _id.get(this)
         });
 
-        _stopCallbacks.get(this).set(stopId, [
+        _stopCallbacks.get(this)?.set(stopId, [
             successCallback
           , errorCallback
         ]);
@@ -456,6 +479,6 @@ export default class Session {
         this.sendMessage(
                 "urn:x-cast:com.google.cast.media"
               , message
-              , null, null);
+              , () => {}, () => {});
     }
 }

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

@@ -6,7 +6,7 @@ import Timeout from "./Timeout";
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.SessionRequest
 export default class SessionRequest {
-    public language: string = null;
+    public language: (string | null) = null;
     public dialRequest: any = null;
 
     constructor (

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

@@ -5,11 +5,11 @@ import { VolumeControlType } from "../enums";
 
 // https://developers.google.com/cast/docs/reference/chrome/chrome.cast.Volume
 export default class Volume {
-    public controlType: VolumeControlType;
-    public stepInterval: number;
+    public controlType?: VolumeControlType;
+    public stepInterval?: number;
 
     constructor (
-            public level: number = null
-          , public muted: boolean = null) {
+            public level: (number | null) = null
+          , public muted: (boolean | null) = null) {
     }
 }

ext/src/shim/cast/index.ts

@@ -129,8 +129,8 @@ export function removeReceiverActionListener (
 }
 
 export function requestSession (
-        successCallback?: RequestSessionSuccessCallback
-      , errorCallback?: ErrorCallback
+        successCallback: RequestSessionSuccessCallback
+      , errorCallback: ErrorCallback
       , _sessionRequest: SessionRequest = apiConfig.sessionRequest): void {
 
     console.info("fx_cast (Debug): cast.requestSession");
@@ -176,8 +176,8 @@ export function requestSession (
 
 export function _requestSession (
         _receiver: Receiver
-      , successCallback?: RequestSessionSuccessCallback
-      , errorCallback?: ErrorCallback): void {
+      , successCallback: RequestSessionSuccessCallback
+      , errorCallback: ErrorCallback): void {
 
     console.info("fx_cast (Debug): cast._requestSession");
 
@@ -241,7 +241,7 @@ export function _requestSession (
         const lastSession = sessionList[sessionList.length - 1];
 
         if (lastSession.status !== SessionStatus.STOPPED) {
-            lastSession.stop(createSession, null);
+            lastSession.stop(createSession, () => {});
         }
     } else {
         createSession();
@@ -354,7 +354,7 @@ onMessage(async message => {
                 const lastSession = sessionList[sessionList.length - 1];
 
                 if (lastSession.status !== SessionStatus.STOPPED) {
-                    lastSession.stop(createSession, null);
+                    lastSession.stop(createSession, () => {});
                 }
             } else {
                 createSession();
@@ -380,9 +380,11 @@ onMessage(async message => {
 
         case "shim:/launchApp": {
             const receiver: Receiver = message.data.receiver;
-            _requestSession(receiver, session => {
-                apiConfig.sessionListener(session);
-            });
+            _requestSession(receiver
+                  , session => {
+                        apiConfig.sessionListener(session);
+                    }
+                  , () => {});
 
             break;
         }

ext/src/shim/cast/media/classes/EditTracksInfoRequest.ts

@@ -4,7 +4,7 @@ export default class EditTracksInfoRequest {
     public requestId = 0;
 
     constructor (
-            public activeTrackIds: number[] = null
-          , public textTrackStyle: string = null) {
+            public activeTrackIds: (number[] | null) = null
+          , public textTrackStyle: (string | null) = null) {
     }
 }

ext/src/shim/cast/media/classes/GenericMediaMetadata.ts

@@ -6,11 +6,11 @@ import { MetadataType } from "../enums";
 
 
 export default class GenericMediaMetadata {
-    public images: Image[] = undefined;
+    public images: (Image[] | undefined) = undefined;
     public metadataType: number = MetadataType.GENERIC;
-    public releaseDate: string = undefined;
-    public releaseYear: number = undefined;
-    public subtitle: string = undefined;
-    public title: string = undefined;
+    public releaseDate: (string | undefined) = undefined;
+    public releaseYear: (number | undefined) = undefined;
+    public subtitle: (string | undefined) = undefined;
+    public title: (string | undefined) = undefined;
     public type: number = MetadataType.GENERIC;
 }

ext/src/shim/cast/media/classes/LoadRequest.ts

@@ -4,13 +4,13 @@ import MediaInfo from "./MediaInfo";
 
 
 export default class LoadRequest {
-    public activeTrackIds: number[] = null;
-    public autoplay: boolean = true;
-    public currentTime: number = null;
+    public activeTrackIds: (number[] | null) = null;
+    public autoplay: (boolean | null) = true;
+    public currentTime: (number | null) = null;
     public customData: any = null;
     public media: MediaInfo;
     public requestId: number = 0;
-    public sessionId: string = null;
+    public sessionId: (string | null) = null;
     public type: string = "LOAD";
 
     constructor (mediaInfo: MediaInfo) {

ext/src/shim/cast/media/classes/Media.ts

@@ -40,17 +40,17 @@ const _lastCurrentTime = new WeakMap<Media, number>();
 
 
 export default class Media {
-    public activeTrackIds: number[] = null;
-    public currentItemId: number = null;
+    public activeTrackIds: (number[] | null) = null;
+    public currentItemId: (number | null) = null;
     public customData: any = null;
     public currentTime: number = 0;
-    public idleReason: string = null;
-    public items: QueueItem[] = null;
-    public loadingItemId: number = null;
-    public media: MediaInfo = null;
+    public idleReason: (string | null) = null;
+    public items: (QueueItem[] | null) = null;
+    public loadingItemId: (number | null) = null;
+    public media: (MediaInfo | null) = null;
     public playbackRate: number = 1;
     public playerState: string = PlayerState.IDLE;
-    public preloadedItemId: number = null;
+    public preloadedItemId: (number | null) = null;
     public repeatMode: string = RepeatMode.OFF;
     public supportedMediaCommands: string[] = [];
     public volume: Volume = new Volume();
@@ -66,8 +66,6 @@ export default class Media {
         _updateListeners.set(this, new Set());
         _sendMediaMessageCallbacks.set(this, new Map());
 
-        _lastCurrentTime.set(this, undefined);
-
 
         sendMessageResponse({
             subject: "bridge:/media/initialize"
@@ -109,19 +107,23 @@ export default class Media {
                     }
 
                     // Call update listeners
-                    for (const listener of _updateListeners.get(this)) {
-                        listener(true);
+                    const updateListeners = _updateListeners.get(this);
+                    if (updateListeners) {
+                        for (const listener of updateListeners) {
+                            listener(true);
+                        }
                     }
 
                     break;
                 }
 
                 case "shim:/media/sendMediaMessageResponse": {
-                    const { messageId, error } = message.data;
+                    const { messageId, error }
+                        : { messageId: string, error: any } = message.data;
+
                     const [ successCallback, errorCallback ]
                             = _sendMediaMessageCallbacks
-                                .get(this)
-                                .get(messageId);
+                                .get(this)?.get(messageId) ?? [];
 
                     if (error && errorCallback) {
                         errorCallback(new _Error(ErrorCode.SESSION_ERROR));
@@ -137,7 +139,7 @@ export default class Media {
     }
 
     public addUpdateListener (listener: UpdateListener): void {
-        _updateListeners.get(this).add(listener);
+        _updateListeners.get(this)?.add(listener);
     }
 
     public editTracksInfo (
@@ -149,12 +151,13 @@ export default class Media {
     }
 
     public getEstimatedTime (): number {
-        if (!this.currentTime) {
+        const lastTime = _lastCurrentTime.get(this);
+
+        if (this.currentTime === undefined || lastTime === undefined) {
             return 0;
         }
 
-        return this.currentTime
-                + ((Date.now() / 1000) - _lastCurrentTime.get(this));
+        return this.currentTime + ((Date.now() / 1000) - lastTime);
     }
 
     public getStatus (
@@ -167,7 +170,7 @@ export default class Media {
     }
 
     public pause (
-            _pauseRequest: PauseRequest
+            _pauseRequest?: PauseRequest
           , successCallback?: SuccessCallback
           , errorCallback?: ErrorCallback): void {
 
@@ -254,7 +257,7 @@ export default class Media {
     }
 
     public removeUpdateListener (listener: UpdateListener) {
-        _updateListeners.get(this).delete(listener);
+        _updateListeners.get(this)?.delete(listener);
     }
 
     public seek (
@@ -307,7 +310,7 @@ export default class Media {
 
         const messageId = uuid();
 
-        _sendMediaMessageCallbacks.get(this).set(messageId, [
+        _sendMediaMessageCallbacks.get(this)?.set(messageId, [
             successCallback
           , errorCallback
         ]);

ext/src/shim/cast/media/classes/MediaInfo.ts

@@ -20,12 +20,12 @@ type Metadata =
       | TvShowMediaMetadata;
 
 export default class MediaInfo {
-    public customData: string = null;
-    public duration: number = null;
-    public metadata: Metadata = null;
+    public customData: any = null;
+    public duration: (number | null) = null;
+    public metadata: (Metadata | null) = null;
     public streamType: string = StreamType.BUFFERED;
-    public textTrackStyle: TextTrackStyle = null;
-    public tracks: Track[] = null;
+    public textTrackStyle: (TextTrackStyle | null) = null;
+    public tracks: (Track[] | null) = null;
 
     constructor (
             public contentId: string

ext/src/shim/cast/media/classes/MovieMediaMetadata.ts

@@ -6,12 +6,12 @@ import { MetadataType } from "../enums";
 
 
 export default class MovieMediaMetadata {
-    public images: Image[] = undefined;
+    public images: (Image[] | undefined) = undefined;
     public metadataType: number = MetadataType.MOVIE;
-    public releaseDate: string = undefined;
-    public releaseYear: number = undefined;
-    public studio: string = undefined;
-    public subtitle: string = undefined;
-    public title: string = undefined;
+    public releaseDate: (string | undefined) = undefined;
+    public releaseYear: (number | undefined) = undefined;
+    public studio: (string | undefined) = undefined;
+    public subtitle: (string | undefined) = undefined;
+    public title: (string | undefined) = undefined;
     public type: number = MetadataType.MOVIE;
 }

ext/src/shim/cast/media/classes/MusicTrackMediaMetadata.ts

@@ -6,18 +6,18 @@ import { MetadataType } from "../enums";
 
 
 export default class MusicTrackMediaMetadata {
-    public albumArtist: string = undefined;
-    public albumName: string = undefined;
-    public artist: string = undefined;
-    public artistName: string = undefined;
-    public composer: string = undefined;
-    public discNumber: number = undefined;
-    public images: Image[] = undefined;
+    public albumArtist: (string | undefined) = undefined;
+    public albumName: (string | undefined) = undefined;
+    public artist: (string | undefined) = undefined;
+    public artistName: (string | undefined) = undefined;
+    public composer: (string | undefined) = undefined;
+    public discNumber: (number | undefined) = undefined;
+    public images: (Image[] | undefined) = undefined;
     public metadataType: number = MetadataType.MUSIC_TRACK;
-    public releaseDate: string = undefined;
-    public releaseYear: number = undefined;
-    public songName: string = undefined;
-    public title: string = undefined;
-    public trackNumber: number = undefined;
+    public releaseDate: (string | undefined) = undefined;
+    public releaseYear: (number | undefined) = undefined;
+    public songName: (string | undefined) = undefined;
+    public title: (string | undefined) = undefined;
+    public trackNumber: (number | undefined) = undefined;
     public type: number = MetadataType.MUSIC_TRACK;
 }

ext/src/shim/cast/media/classes/PhotoMediaMetadata.ts

@@ -6,15 +6,15 @@ import { MetadataType } from "../enums";
 
 
 export default class PhotoMediaMetadata {
-    public artist: string = undefined;
-    public creationDateTime: string = undefined;
-    public height: number = undefined;
-    public images: Image[] = undefined;
-    public latitude: number = undefined;
-    public location: string = undefined;
-    public longitude: number = undefined;
+    public artist: (string | undefined) = undefined;
+    public creationDateTime: (string | undefined) = undefined;
+    public height: (number | undefined) = undefined;
+    public images: (Image[] | undefined) = undefined;
+    public latitude: (number | undefined) = undefined;
+    public location: (string | undefined) = undefined;
+    public longitude: (number | undefined) = undefined;
     public metadataType: number = MetadataType.PHOTO;
-    public title: string = undefined;
+    public title: (string | undefined) = undefined;
     public type: number = MetadataType.PHOTO;
-    public width: number = undefined;
+    public width: (number | undefined) = undefined;
 }

ext/src/shim/cast/media/classes/QueueInsertItemsRequest.ts

@@ -5,9 +5,9 @@ import QueueItem from "./QueueItem";
 
 export default class QueueInsertItemsRequest {
     public customData: any = null;
-    public insertBefore: number = null;
-    public requestId: number = null;
-    public sessionId: string = null;
+    public insertBefore: (number | null) = null;
+    public requestId: (number | null) = null;
+    public sessionId: (string | null) = null;
     public type: string = "QUEUE_INSERT";
 
     constructor (

ext/src/shim/cast/media/classes/QueueItem.ts

@@ -4,12 +4,12 @@ import MediaInfo from "./MediaInfo";
 
 
 export default class QueueItem {
-    public activeTrackIds: number[] = null;
+    public activeTrackIds: (number[] | null) = null;
     public autoplay: boolean = true;
     public customData: any = null;
-    public itemId: number = null;
+    public itemId: (number | null) = null;
     public media: MediaInfo;
-    public playbackDuration: number = null;
+    public playbackDuration: (number | null) = null;
     public preloadTime: number = 0;
     public startTime: number = 0;
 

ext/src/shim/cast/media/classes/QueueLoadRequest.ts

@@ -8,8 +8,8 @@ import { RepeatMode } from "../enums";
 export default class QueueLoadRequest {
     public customData: any = null;
     public repeatMode: string = RepeatMode.OFF;
-    public requestId: number = null;
-    public sessionId: string = null;
+    public requestId: (number | null) = null;
+    public sessionId: (string | null) = null;
     public startIndex: number = 0;
     public type: string = "QUEUE_LOAD";
 

ext/src/shim/cast/media/classes/QueueRemoveItemsRequest.ts

@@ -2,8 +2,8 @@
 
 export default class QueueRemoveItemsRequest {
     public customData: any = null;
-    public requestId: number = null;
-    public sessionId: string = null;
+    public requestId: (number | null) = null;
+    public sessionId: (string | null) = null;
     public type: string = "QUEUE_REMOVE";
 
     constructor (

ext/src/shim/cast/media/classes/QueueReorderItemsRequest.ts

@@ -2,9 +2,9 @@
 
 export default class QueueReorderItemsRequest {
     public customData: any = null;
-    public insertBefore: number = null;
-    public requestId: number = null;
-    public sessionId: string = null;
+    public insertBefore: (number | null) = null;
+    public requestId: (number | null) = null;
+    public sessionId: (string | null) = null;
     public type: string = "QUEUE_REORDER";
 
     constructor (

ext/src/shim/cast/media/classes/QueueSetPropertiesRequest.ts

@@ -2,8 +2,8 @@
 
 export default class QueueSetPropertiesRequest {
     public customData: any = null;
-    public repeatMode: string = null;
-    public requestId: number = null;
-    public sessionId: string = null;
+    public repeatMode: (string | null) = null;
+    public requestId: (number | null) = null;
+    public sessionId: (string | null) = null;
     public type: string = "QUEUE_UPDATE";
 }

ext/src/shim/cast/media/classes/QueueUpdateItemsRequest.ts

@@ -5,8 +5,8 @@ import QueueItem from "./QueueItem";
 
 export default class QueueUpdateItemsRequest {
     public customData: any = null;
-    public requestId: number = null;
-    public sessionId: string = null;
+    public requestId: (number | null) = null;
+    public sessionId: (string | null) = null;
     public type: string = "QUEUE_UPDATE";
 
     constructor (

ext/src/shim/cast/media/classes/SeekRequest.ts

@@ -1,7 +1,7 @@
 "use strict";
 
 export default class SeekRequest {
-    public currentTime: number = null;
+    public currentTime: (number | null) = null;
     public customData: any = null;
-    public resumeState: string = null;
+    public resumeState: (string | null) = null;
 }

ext/src/shim/cast/media/classes/TextTrackStyle.ts

@@ -1,16 +1,16 @@
 "use strict";
 
 export default class TextTrackStyle {
-    public backgroundColor: string = null;
+    public backgroundColor: (string | null) = null;
     public customData: any = null;
-    public edgeColor: string = null;
-    public edgeType: string = null;
-    public fontFamily: string = null;
-    public fontGenericFamily: string = null;
-    public fontScale: number = null;
-    public fontStyle: string = null;
-    public foregroundColor: string = null;
-    public windowColor: string = null;
-    public windowRoundedCornerRadius: number = null;
-    public windowType: string = null;
+    public edgeColor: (string | null) = null;
+    public edgeType: (string | null) = null;
+    public fontFamily: (string | null) = null;
+    public fontGenericFamily: (string | null) = null;
+    public fontScale: (number | null) = null;
+    public fontStyle: (string | null) = null;
+    public foregroundColor: (string | null) = null;
+    public windowColor: (string | null) = null;
+    public windowRoundedCornerRadius: (number | null) = null;
+    public windowType: (string | null) = null;
 }

ext/src/shim/cast/media/classes/Track.ts

@@ -2,11 +2,11 @@
 
 export default class Track {
     public customData: any = null;
-    public language: string = null;
-    public name: string = null;
-    public subtype: string = null;
-    public trackContentId: string = null;
-    public trackContentType: string = null;
+    public language: (string | null) = null;
+    public name: (string | null) = null;
+    public subtype: (string | null) = null;
+    public trackContentId: (string | null) = null;
+    public trackContentType: (string | null) = null;
 
     constructor (
             public trackId: number

ext/src/shim/cast/media/classes/TvShowMediaMetadata.ts

@@ -6,16 +6,16 @@ import { MetadataType } from "../enums";
 
 
 export default class TvShowMediaMetadata {
-    public episode: number = undefined;
-    public episodeNumber: number = undefined;
-    public episodeTitle: string = undefined;
-    public images: Image[] = undefined;
+    public episode: (number | undefined) = undefined;
+    public episodeNumber: (number | undefined) = undefined;
+    public episodeTitle: (string | undefined) = undefined;
+    public images: (Image[] | undefined) = undefined;
     public metadataType: number = MetadataType.TV_SHOW;
-    public originalAirdate: string = undefined;
-    public releaseYear: number = undefined;
-    public season: number = undefined;
-    public seasonNumber: number = undefined;
-    public seriesTitle: string = undefined;
-    public title: string = undefined;
+    public originalAirdate: (string | undefined) = undefined;
+    public releaseYear: (number | undefined) = undefined;
+    public season: (number | undefined) = undefined;
+    public seasonNumber: (number | undefined) = undefined;
+    public seriesTitle: (string | undefined) = undefined;
+    public title: (string | undefined) = undefined;
     public type: number = MetadataType.TV_SHOW;
 }

ext/src/shim/content.ts

@@ -15,7 +15,7 @@ import { CAST_LOADER_SCRIPT_URL
  * URLs, replace it with the standard API URL, the request for
  * which is handled in the main script.
  */
-const { get, set } = Reflect.getOwnPropertyDescriptor(
+const desc = Reflect.getOwnPropertyDescriptor(
         HTMLScriptElement.prototype.wrappedJSObject, "src");
 
 Reflect.defineProperty(
@@ -23,13 +23,13 @@ Reflect.defineProperty(
 
     configurable: true
   , enumerable: true
-  , get
+  , get: desc?.get
 
-  , set: exportFunction(function (value) {
+  , set: exportFunction(function setFunc (this: HTMLScriptElement, value) {
         if (CAST_SCRIPT_URLS.includes(value)) {
-            return set.call(this, CAST_LOADER_SCRIPT_URL);
+            return desc?.set?.call(this, CAST_LOADER_SCRIPT_URL);
         }
 
-        return set.call(this, value);
+        return desc?.set?.call(this, value);
     }, window)
 });

ext/src/shim/eventMessageChannel.ts

@@ -25,12 +25,14 @@ export function onMessage (listener: ListenerFunc): ListenerObject {
         ev.stopPropagation();
     }
 
+    // @ts-ignore
     document.addEventListener(
             "__castMessage"
           , on__castMessage, true);
 
     return {
         disconnect () {
+            // @ts-ignore
             document.removeEventListener(
                     "__castMessage"
                   , on__castMessage, true);
@@ -52,12 +54,14 @@ export function onMessageResponse (listener: ListenerFunc): ListenerObject {
         listener(JSON.parse(ev.detail));
     }
 
+    // @ts-ignore
     document.addEventListener(
             "__castMessageResponse"
           , on__castMessageResponse, true);
 
     return {
         disconnect () {
+            // @ts-ignore
             document.removeEventListener(
                     "__castMessageResponse"
                   , on__castMessageResponse, true);

ext/src/shim/framework/classes/CastOptions.ts

@@ -5,8 +5,8 @@ import * as cast from "../../cast";
 
 export default class CastOptions {
     public autoJoinPolicy: string = cast.AutoJoinPolicy.TAB_AND_ORIGIN_SCOPED;
-    public language: string = null;
-    public receiverApplicationId: string = null;
+    public language: (string | null) = null;
+    public receiverApplicationId: (string | null) = null;
     public resumeSavedSession: boolean = true;
 
     constructor (options: CastOptions = ({} as CastOptions)) {

ext/src/shim/framework/classes/RemotePlayer.ts

@@ -15,19 +15,19 @@ export default class RemotePlayer {
     public canControlVolume = false;
     public canPause = false;
     public canSeek = false;
-    public controller: RemotePlayerController = null;
+    public controller: (RemotePlayerController | null) = null;
     public currentTime = 0;
     public displayName = "";
     public displayStatus = "";
     public duration = 0;
-    public imageUrl: string = null;
+    public imageUrl: (string | null) = null;
     public isConnected = false;
     public isMediaLoaded = false;
     public isMuted = false;
     public isPaused = false;
-    public mediaInfo: cast.media.MediaInfo = null;
-    public playerState: string = null;
-    public savedPlayerState: SavedPlayerState = null;
+    public mediaInfo: (cast.media.MediaInfo | null) = null;
+    public playerState: (string | null) = null;
+    public savedPlayerState: (SavedPlayerState | null) = null;
     public statusText = "";
     public title = "";
     public volumeLevel = 1;

ext/src/shim/framework/classes/SessionStateEventData.ts

@@ -10,7 +10,7 @@ export default class SessionStateEventData extends EventData {
     constructor (
             public session: CastSession
           , public sessionState: string
-          , public errorCode: string = null) {
+          , public errorCode: (string | null) = null) {
 
         super(SessionEventType.APPLICATION_STATUS_CHANGED);
     }

ext/src/shim/types.ts

@@ -11,5 +11,5 @@ export type MessageListener = (namespace: string, message: string) => void;
 export type UpdateListener = (isAlive: boolean) => void;
 export type LoadSuccessCallback = (media: Media) => void;
 
-export type Callbacks = [ SuccessCallback, ErrorCallback ];
+export type Callbacks = [ SuccessCallback?, ErrorCallback? ];
 export type CallbacksMap = Map<string, Callbacks>;

ext/src/ui/options/Bridge.tsx

@@ -68,12 +68,12 @@ interface BridgeState {
     isUpdateAvailable: boolean;
     wasErrorCheckingUpdates: boolean;
     checkUpdatesEllipsis: string;
-    updateStatus: string;
+    updateStatus?: string;
 }
 
 export default class Bridge extends Component<BridgeProps, BridgeState> {
     private updateData: any;
-    private updateStatusTimeout: number;
+    private updateStatusTimeout?: number;
 
     constructor (props: BridgeProps) {
         super(props);
@@ -83,7 +83,6 @@ export default class Bridge extends Component<BridgeProps, BridgeState> {
           , isUpdateAvailable: false
           , wasErrorCheckingUpdates: false
           , checkUpdatesEllipsis: "..."
-          , updateStatus: null
         };
 
         this.onCheckUpdates = this.onCheckUpdates.bind(this);
@@ -142,7 +141,7 @@ export default class Bridge extends Component<BridgeProps, BridgeState> {
 
         let statusIcon: string;
         let statusTitle: string;
-        let statusText: string;
+        let statusText: (string | null);
 
         if (!this.props.info) {
             statusIcon = "assets/icons8-cancel-120.png";
@@ -156,6 +155,8 @@ export default class Bridge extends Component<BridgeProps, BridgeState> {
                 statusIcon = "assets/icons8-warn-120.png";
                 statusTitle = _("optionsBridgeIssueStatusTitle");
             }
+
+            statusText = null;
         }
 
         return (
@@ -213,11 +214,14 @@ export default class Bridge extends Component<BridgeProps, BridgeState> {
         this.setState({
             isCheckingUpdates: false
           , isUpdateAvailable
-          , updateStatus: !isUpdateAvailable
-                ? _("optionsBridgeUpdateStatusNoUpdates")
-                : null
         });
 
+        if (!isUpdateAvailable) {
+            this.setState({
+                updateStatus: _("optionsBridgeUpdateStatusNoUpdates")
+            });
+        }
+
         this.showUpdateStatus();
     }
 
@@ -237,7 +241,7 @@ export default class Bridge extends Component<BridgeProps, BridgeState> {
         }
         this.updateStatusTimeout = window.setTimeout(() => {
             this.setState({
-                updateStatus: null
+                updateStatus: undefined
             });
         }, 1500);
     }

ext/src/ui/options/EditableList.tsx

@@ -23,7 +23,7 @@ interface EditableListState {
 export default class EditableList extends Component<
         EditableListProps, EditableListState> {
 
-    private rawViewTextArea: HTMLTextAreaElement;
+    private rawViewTextArea: (HTMLTextAreaElement | null) = null;
 
     constructor (props: EditableListProps) {
         super(props);
@@ -140,13 +140,13 @@ export default class EditableList extends Component<
             if ("itemPattern" in this.props) {
                 for (const item of newItems) {
                     if (!this.props.itemPattern.test(item)) {
-                        this.rawViewTextArea.setCustomValidity(
+                        this.rawViewTextArea?.setCustomValidity(
                                 this.props.itemPatternError(item));
                         return;
                     }
                 }
 
-                this.rawViewTextArea.setCustomValidity("");
+                this.rawViewTextArea?.setCustomValidity("");
             }
 
             this.props.onChange(newItems);
@@ -154,6 +154,10 @@ export default class EditableList extends Component<
     }
 
     private handleRawViewTextAreaChange (ev: React.ChangeEvent<HTMLTextAreaElement>) {
+        if (!this.rawViewTextArea) {
+            return;
+        }
+
         if (this.rawViewTextArea.scrollHeight > this.rawViewTextArea.clientHeight) {
             this.rawViewTextArea.style.height = `${this.rawViewTextArea.scrollHeight}px`;
         }

ext/src/ui/options/EditableListItem.tsx

@@ -23,7 +23,7 @@ interface EditableListItemState {
 export default class EditableListItem extends Component<
         EditableListItemProps, EditableListItemState> {
 
-    private input: HTMLInputElement;
+    private input: (HTMLInputElement | null) = null;
 
     constructor (props: EditableListItemProps) {
         super(props);
@@ -96,7 +96,7 @@ export default class EditableListItem extends Component<
             editing: true
           , editValue: this.props.text
         }, () => {
-            this.input.focus();
+            this.input?.focus();
         });
     }
 

ext/src/ui/options/index.tsx

@@ -10,6 +10,7 @@ import Bridge from "./Bridge";
 import EditableList from "./EditableList";
 
 import bridge, { BridgeInfo } from "../../lib/bridge";
+import logger from "../../lib/logger";
 import options, { Options } from "../../lib/options";
 import { REMOTE_MATCH_PATTERN_REGEX } from "../../lib/utils";
 
@@ -83,25 +84,23 @@ function getInputValue (input: HTMLInputElement) {
 
 interface OptionsAppState {
     hasLoaded: boolean;
-    options: Options;
-    bridgeInfo: BridgeInfo;
-    platform: string;
     bridgeLoading: boolean;
     isFormValid: boolean;
     hasSaved: boolean;
+
+    options?: Options;
+    bridgeInfo?: BridgeInfo;
+    platform?: string;
 }
 
 class OptionsApp extends Component<{}, OptionsAppState> {
-    private form: HTMLFormElement;
+    private form: (HTMLFormElement | null) = null;
 
     constructor (props: {}) {
         super(props);
 
         this.state = {
             hasLoaded: false
-          , options: null
-          , bridgeInfo: null
-          , platform: null
           , bridgeLoading: true
           , isFormValid: true
           , hasSaved: false
@@ -113,11 +112,11 @@ class OptionsApp extends Component<{}, OptionsAppState> {
         this.handleInputChange = this.handleInputChange.bind(this);
         this.handleWhitelistChange = this.handleWhitelistChange.bind(this);
 
-        this.handleReceiverSelectorTypeChange
-                = this.handleReceiverSelectorTypeChange.bind(this);
+        this.handleReceiverSelectorTypeChange =
+                this.handleReceiverSelectorTypeChange.bind(this);
 
-        this.getWhitelistItemPatternError
-                = this.getWhitelistItemPatternError.bind(this);
+        this.getWhitelistItemPatternError =
+                this.getWhitelistItemPatternError.bind(this);
     }
 
     public async componentDidMount () {
@@ -126,14 +125,18 @@ class OptionsApp extends Component<{}, OptionsAppState> {
           , options: await options.getAll()
         });
 
-        const bridgeInfo = await bridge.getInfo();
-        const { os } = await browser.runtime.getPlatformInfo();
+        try {
+            const bridgeInfo = await bridge.getInfo();
+            const { os } = await browser.runtime.getPlatformInfo();
 
-        this.setState({
-            bridgeInfo
-          , platform: os
-          , bridgeLoading: false
-        });
+            this.setState({
+                bridgeInfo
+              , platform: os
+              , bridgeLoading: false
+            });
+        } catch {
+            logger.error("Failed to fetch bridge/platform info.");
+        }
     }
 
     public render () {
@@ -143,9 +146,10 @@ class OptionsApp extends Component<{}, OptionsAppState> {
 
         return (
             <div>
-                <Bridge info={ this.state.bridgeInfo }
-                        platform={ this.state.platform }
-                        loading={ this.state.bridgeLoading } />
+                { this.state.bridgeInfo && this.state.platform &&
+                    <Bridge info={ this.state.bridgeInfo }
+                            platform={ this.state.platform }
+                            loading={ this.state.bridgeLoading } /> }
 
                 <form id="form" ref={ form => { this.form = form; }}
                         onSubmit={ this.handleFormSubmit }
@@ -163,7 +167,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="mediaEnabled"
                                        type="checkbox"
-                                       checked={ this.state.options.mediaEnabled }
+                                       checked={ this.state.options?.mediaEnabled }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -175,7 +179,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="mediaSyncElement"
                                        type="checkbox"
-                                       checked={ this.state.options.mediaSyncElement }
+                                       checked={ this.state.options?.mediaSyncElement }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -190,7 +194,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="mediaStopOnUnload"
                                        type="checkbox"
-                                       checked={ this.state.options.mediaStopOnUnload }
+                                       checked={ this.state.options?.mediaStopOnUnload }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -202,7 +206,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="mediaOverlayEnabled"
                                        type="checkbox"
-                                       checked={ this.state.options.mediaOverlayEnabled }
+                                       checked={ this.state.options?.mediaOverlayEnabled }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -219,7 +223,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="localMediaEnabled"
                                        type="checkbox"
-                                       checked={ this.state.options.localMediaEnabled }
+                                       checked={ this.state.options?.localMediaEnabled }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -240,7 +244,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                                        required
                                        min="1025"
                                        max="65535"
-                                       value={ this.state.options.localMediaServerPort }
+                                       value={ this.state.options?.localMediaServerPort }
                                        onChange={ this.handleInputChange } />
                             </div>
                         </label>
@@ -258,7 +262,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="mirroringEnabled"
                                        type="checkbox"
-                                       checked={ this.state.options.mirroringEnabled }
+                                       checked={ this.state.options?.mirroringEnabled }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -274,7 +278,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                                 <input name="mirroringAppId"
                                        type="text"
                                        required
-                                       value={ this.state.options.mirroringAppId }
+                                       value={ this.state.options?.mirroringAppId }
                                        onChange={ this.handleInputChange } />
                                 <div className="option__description">
                                     { _("optionsMirroringAppIdDescription") }
@@ -298,7 +302,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                                 </div>
                                 <div className="option__control">
                                     <select name="receiverSelectorType"
-                                            value={ this.state.options.receiverSelectorType }
+                                            value={ this.state.options?.receiverSelectorType }
                                             onChange={ this.handleReceiverSelectorTypeChange }>
                                         <option value={ ReceiverSelectorType.Popup }>
                                             { _("optionsReceiverSelectorTypeBrowser") }
@@ -314,7 +318,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="receiverSelectorWaitForConnection"
                                        type="checkbox"
-                                       checked={ this.state.options.receiverSelectorWaitForConnection }
+                                       checked={ this.state.options?.receiverSelectorWaitForConnection }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -329,7 +333,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="receiverSelectorCloseIfFocusLost"
                                        type="checkbox"
-                                       checked={ this.state.options.receiverSelectorCloseIfFocusLost }
+                                       checked={ this.state.options?.receiverSelectorCloseIfFocusLost }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -350,7 +354,7 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                             <div className="option__control">
                                 <input name="userAgentWhitelistEnabled"
                                        type="checkbox"
-                                       checked={ this.state.options.userAgentWhitelistEnabled }
+                                       checked={ this.state.options?.userAgentWhitelistEnabled }
                                        onChange={ this.handleInputChange } />
                             </div>
                             <div className="option__label">
@@ -363,10 +367,11 @@ class OptionsApp extends Component<{}, OptionsAppState> {
                                 { _("optionsUserAgentWhitelistContent") }
                             </div>
                             <div className="option__control">
-                                <EditableList data={ this.state.options.userAgentWhitelist }
-                                              onChange={ this.handleWhitelistChange }
-                                              itemPattern={ REMOTE_MATCH_PATTERN_REGEX }
-                                              itemPatternError={ this.getWhitelistItemPatternError } />
+                                { this.state.options?.userAgentWhitelist && 
+                                    <EditableList data={ this.state.options.userAgentWhitelist }
+                                                  onChange={ this.handleWhitelistChange }
+                                                  itemPattern={ REMOTE_MATCH_PATTERN_REGEX }
+                                                  itemPatternError={ this.getWhitelistItemPatternError } /> }
                             </div>
                         </div>
                     </fieldset>
@@ -400,20 +405,22 @@ class OptionsApp extends Component<{}, OptionsAppState> {
     private async handleFormSubmit (ev: React.FormEvent<HTMLFormElement>) {
         ev.preventDefault();
 
-        this.form.reportValidity();
+        this.form?.reportValidity();
 
         try {
-            await options.setAll(this.state.options);
+            if (this.state.options) {
+                await options.setAll(this.state.options);
 
-            this.setState({
-                hasSaved: true
-            }, () => {
-                window.setTimeout(() => {
-                    this.setState({
-                        hasSaved: false
-                    });
-                }, 1000);
-            });
+                this.setState({
+                    hasSaved: true
+                }, () => {
+                    window.setTimeout(() => {
+                        this.setState({
+                            hasSaved: false
+                        });
+                    }, 1000);
+                });
+            }
         } catch (err) {
             console.error("Failed to save options");
         }
@@ -422,14 +429,20 @@ class OptionsApp extends Component<{}, OptionsAppState> {
     private handleFormChange (ev: React.FormEvent<HTMLFormElement>) {
         ev.preventDefault();
 
-        this.setState({
-            isFormValid: this.form.checkValidity()
-        });
+        const isFormValid = this.form?.checkValidity();
+        if (isFormValid !== undefined) {
+            this.setState({
+                isFormValid
+            });
+        }
     }
 
     private handleInputChange (ev: React.ChangeEvent<HTMLInputElement>) {
         this.setState(currentState => {
-            currentState.options[ev.target.name] = getInputValue(ev.target);
+            if (currentState.options) {
+                currentState.options[ev.target.name] = getInputValue(ev.target);
+            }
+
             return currentState;
         });
     }
@@ -438,14 +451,20 @@ class OptionsApp extends Component<{}, OptionsAppState> {
             ev: React.ChangeEvent<HTMLSelectElement>) {
 
         this.setState(currentState => {
-            currentState.options[ev.target.name] = parseInt(ev.target.value);
+            if (currentState.options) {
+                currentState.options[ev.target.name] = parseInt(ev.target.value);
+            }
+
             return currentState;
         });
     }
 
     private handleWhitelistChange (whitelist: string[]) {
         this.setState(currentState => {
-            currentState.options.userAgentWhitelist = whitelist;
+            if (currentState.options) {
+                currentState.options.userAgentWhitelist = whitelist;
+            }
+
             return currentState;
         });
     }

ext/src/ui/popup/index.tsx

@@ -31,14 +31,15 @@ interface PopupAppState {
     mediaType: ReceiverSelectorMediaType;
     availableMediaTypes: ReceiverSelectorMediaType;
     isLoading: boolean;
-    filePath: string;
-    requestedAppId: string;
+
+    filePath?: string;
+    requestedAppId?: string;
 }
 
 class PopupApp extends Component<{}, PopupAppState> {
-    private port: browser.runtime.Port;
-    private win: browser.windows.Window;
-    private defaultMediaType: ReceiverSelectorMediaType;
+    private port?: browser.runtime.Port;
+    private win?: browser.windows.Window;
+    private defaultMediaType?: ReceiverSelectorMediaType;
 
     constructor (props: {}) {
         super(props);
@@ -48,8 +49,6 @@ class PopupApp extends Component<{}, PopupAppState> {
           , mediaType: ReceiverSelectorMediaType.App
           , availableMediaTypes: ReceiverSelectorMediaType.App
           , isLoading: false
-          , filePath: null
-          , requestedAppId: null
         };
 
         // Store window ref
@@ -78,7 +77,12 @@ class PopupApp extends Component<{}, PopupAppState> {
                 }
 
                 case "popup:/populateReceiverList": {
-                    this.defaultMediaType = message.data.defaultMediaType;
+                    const { receivers, availableMediaTypes, defaultMediaType }
+                        : { receivers: Receiver[]
+                          , availableMediaTypes: ReceiverSelectorMediaType
+                          , defaultMediaType: ReceiverSelectorMediaType } = message.data;
+
+                    this.defaultMediaType = defaultMediaType;
 
                     this.setState({
                         receivers: message.data.receivers
@@ -99,6 +103,10 @@ class PopupApp extends Component<{}, PopupAppState> {
 
     public componentDidUpdate () {
         setTimeout(() => {
+            if (this.win?.id === undefined) {
+                return;
+            }
+
             // Fit window to content height
             const frameHeight = window.outerHeight - window.innerHeight;
             const windowHeight = document.body.clientHeight + frameHeight;
@@ -137,8 +145,9 @@ class PopupApp extends Component<{}, PopupAppState> {
                         <option value={ ReceiverSelectorMediaType.App }
                                 disabled={ !(this.state.availableMediaTypes
                                         & ReceiverSelectorMediaType.App) }>
-                            { knownApps[this.state.requestedAppId]
-                                    ?? _("popupMediaTypeApp") }
+                            { (this.state.requestedAppId
+                                    && knownApps[this.state.requestedAppId])
+                                        ?? _("popupMediaTypeApp") }
                         </option>
                         <option value={ ReceiverSelectorMediaType.Tab }
                                 disabled={ !(this.state.availableMediaTypes
@@ -157,7 +166,7 @@ class PopupApp extends Component<{}, PopupAppState> {
                                 disabled={ !(this.state.availableMediaTypes
                                         & ReceiverSelectorMediaType.File) }>
                             { this.state.filePath
-                                ? truncatedFileName
+                                ? truncatedFileName!
                                 : _("popupMediaTypeFile") }
                         </option>
                     </select>
@@ -188,7 +197,7 @@ class PopupApp extends Component<{}, PopupAppState> {
             isLoading: true
         });
 
-        this.port.postMessage({
+        this.port?.postMessage({
             subject: "receiverSelector:/selected"
           , data: {
                 receiver
@@ -199,7 +208,7 @@ class PopupApp extends Component<{}, PopupAppState> {
     }
 
     private onStop (receiver: Receiver) {
-        this.port.postMessage({
+        this.port?.postMessage({
             subject: "receiverSelector:/stop"
           , data: { receiver }
         });
@@ -220,9 +229,11 @@ class PopupApp extends Component<{}, PopupAppState> {
             }
 
             // Set media type to default if failed to set filePath
-            this.setState({
-                mediaType: this.defaultMediaType
-            });
+            if (this.defaultMediaType) {
+                this.setState({
+                    mediaType: this.defaultMediaType
+                });
+            }
         } else {
             this.setState({
                 mediaType
@@ -230,7 +241,7 @@ class PopupApp extends Component<{}, PopupAppState> {
         }
 
         this.setState({
-            filePath: null
+            filePath: undefined
         });
     }
 }
@@ -279,6 +290,10 @@ class ReceiverEntry extends Component<ReceiverEntryProps, ReceiverEntryState> {
     }
 
     public render () {
+        if (!this.props.receiver.status) {
+            return;
+        }
+
         const { application } = this.props.receiver.status;
 
         return (
@@ -287,7 +302,7 @@ class ReceiverEntry extends Component<ReceiverEntryProps, ReceiverEntryState> {
                     { this.props.receiver.friendlyName }
                 </div>
                 <div className="receiver__address"
-                     title={ !application.isIdleScreen && application.statusText }>
+                     title={ !application.isIdleScreen ? application.statusText : "" }>
                     { application.isIdleScreen
                         ? `${this.props.receiver.host}:${this.props.receiver.port}`
                         : application.statusText }
@@ -311,6 +326,10 @@ class ReceiverEntry extends Component<ReceiverEntryProps, ReceiverEntryState> {
     }
 
     private handleCast () {
+        if (!this.props.receiver.status) {
+            return;
+        }
+
         const { application } = this.props.receiver.status;
 
         if (!application.isIdleScreen && this.state.showAlternateAction) {

tsconfig.json

@@ -7,5 +7,6 @@
       , "removeComments": true
       , "resolveJsonModule": true
       , "target": "es6"
+      . "strict": true
     }
 }