Auto merge of #604 - saneyuki:nullable, r=saneyuki

chore(TypeScript): Enable 'strictNullChecks' option

This tries to enable [`--strictNullChecks` option](microsoft/TypeScript#7140) of TypeScript compiler.

- [Non-nullable types by ahejlsberg · Pull Request #7140 · Microsoft/TypeScript](microsoft/TypeScript#7140)
  - [Non-strict type checking · Issue #7489 · Microsoft/TypeScript](microsoft/TypeScript#7489)
  - [[Request for feedback] Nullable types, `null` and `undefined` · Issue #7426 · Microsoft/TypeScript](microsoft/TypeScript#7426)
- [Control flow based type analysis by ahejlsberg · Pull Request #8010 · Microsoft/TypeScript](microsoft/TypeScript#8010)

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src/client/rize/adapter/NotificationService.ts

@@ -80,15 +80,15 @@ function requestPermittion(): Rx.Observable<boolean> {
 }
 
 function showNotification(topic: NotifedTopic): Rx.Observable<void> {
-    let notification: Notification = new (window as any).Notification(topic.title, {
+    let notification: Notification | void = new (window as any).Notification(topic.title, {
         body: topic.body,
         icon: topic.icon,
     });
     const timeout = Rx.Observable.empty<void>().delay(5 * 1000);
-    const click = Rx.Observable.fromEvent<void>(notification, 'click').take(1);
+    const click = Rx.Observable.fromEvent<void>(notification!, 'click').take(1);
     const close: Rx.Observable<void> = click.race(timeout).do(function(){
         notification.close();
-        notification = null;
+        notification = undefined;
     });
     return close.share();
 }

src/client/rize/rize.ts

@@ -50,7 +50,7 @@ export class RizeClient {
             console.log(data.value);
         });
 
-        const view = React.createElement(RizeAppView, null);
+        const view = React.createElement(RizeAppView, undefined);
         const mountpoint = document.getElementById('js-mountpoint-app');
         ReactDOM.render(view, mountpoint);
     }

src/client/script/adapter/AudioDriver.ts

@@ -24,7 +24,7 @@
  */
 
 export class AudioDriver {
-    _audio: HTMLAudioElement;
+    private _audio: HTMLAudioElement | void;
 
     constructor(path: string) {
         const audio = new Audio();
@@ -34,6 +34,10 @@ export class AudioDriver {
         this._audio = audio;
     }
 
+    destroy(): void {
+        this._audio = undefined;
+    }
+
     play(): void {
         this._audio.play();
     }

src/client/script/domain/Channel.ts

@@ -36,9 +36,9 @@ export class Channel {
     private _userList: Array<User>;
     private _unread: number;
     private _messageBuffer: Array<Message>;
-    private _network: Network;
+    private _network: Network | void;
 
-    constructor(raw: any, network: Network = null) {
+    constructor(raw: any, network: Network | void = undefined) {
         this.id = raw.id;
 
         this.name = raw.name;
@@ -55,13 +55,10 @@ export class Channel {
 
         this._unread = raw.unread;
 
-        let messages: Array<Message> = null;
+        let messages: Array<Message> = [];
         if (Array.isArray(raw.messages)) {
             messages = raw.messages;
         }
-        else {
-            messages = [];
-        }
 
         this._messageBuffer = messages;
         this._network = network;
@@ -79,7 +76,7 @@ export class Channel {
         return this._userList;
     }
 
-    getNetwork(): Network {
+    getNetwork(): Network | void {
         return this._network;
     }
 

src/client/script/domain/ChannelDomain.ts

@@ -123,7 +123,6 @@ export class ChannelDomain {
 
     dispose(): void {
         this._ignitionDisposable.unsubscribe();
-        this._notableDispatcher = null;
     }
 
     getId(): ChannelId {

src/client/script/domain/DomainState.ts

@@ -64,13 +64,13 @@ export class SelectedTab {
 export class DomainState {
 
     private _networkSet: NetworkSetDomain;
-    private _latestCurrentTab: SelectedTab;
+    private _latestCurrentTab: SelectedTab | void;
     private _currentTab: Rx.Observable<SelectedTab>;
     private _notifiableMessage: Rx.Observable<RecievedMessage>;
 
     constructor(gateway: MessageGateway) {
         this._networkSet = new NetworkSetDomain(gateway);
-        this._latestCurrentTab = null;
+        this._latestCurrentTab = undefined;
 
         // In most of case, a rendering operation is depend on the source of `selectTab()`.
         // So this observable should be on the next event loop.
@@ -79,18 +79,18 @@ export class DomainState {
         }).observeOn(Rx.Scheduler.asap).share();
 
         this._notifiableMessage = this._networkSet.recievedNotifiableMessage()
-            .withLatestFrom(this._currentTab, function (data, current): RecievedMessage {
+            .withLatestFrom(this._currentTab, function (data, current): RecievedMessage | void {
                 const isSameChannel: boolean = current.channelId.mapOr(false, function (current: ChannelId) {
                     return data.channelId === current;
                 });
                 if (isSameChannel) {
-                    return null;
+                    return undefined;
                 }
 
                 return data;
             }).filter(function (data) {
-                return data !== null;
-            }).share();
+                return data !== undefined;
+            }).map((data) => data!).share();
     }
 
     /**
@@ -100,7 +100,7 @@ export class DomainState {
         return this._networkSet.legacy;
     }
 
-    get currentTab(): SelectedTab {
+    get currentTab(): SelectedTab | void {
         return this._latestCurrentTab;
     }
 
@@ -155,7 +155,7 @@ function selectTab(gateway: MessageGateway, intent: UIActionDispatcher, set: Net
     });
 
     const removedNetwork = set.removedNetwork().withLatestFrom(set.getNetworkList(), function(_, list) {
-        let tab: SelectedTab = null;
+        let tab: SelectedTab;
         if (list.length === 0) {
             tab = new SelectedTab(CurrentTabType.SETTING, 'connect');
         }
@@ -183,7 +183,7 @@ function selectTab(gateway: MessageGateway, intent: UIActionDispatcher, set: Net
     });
 
     const initial = set.initialState().map(function(data){
-        let tab: SelectedTab = null;
+        let tab: SelectedTab;
 
         const idIsSetting = data.active.mapOr(true, function(id){
             return (typeof id !== 'number');

src/client/script/domain/NetworkDomain.ts

@@ -126,15 +126,7 @@ export class NetworkDomain {
     }
 
     dispose(): void {
-        this._data = null;
-        this._nickname = null;
-        this._joinedChannel = null;
-        this._partedChannel = null;
-
-        this._notableMsgDispatcher = null;
-
         this._subscribed.unsubscribe();
-        this._subscribed = null;
     }
 
     getId(): number {

src/client/script/intent/action/ConnectionActionCreator.ts

@@ -35,7 +35,7 @@ export class ConnectionActionCreator {
     }
 
     dispose(): void {
-        this._dispatcher = null;
+        (this as any)._dispatcher = undefined;
     }
 
     dispatcher(): ConnectionActionDispatcher {

src/client/script/output/NotificationPresenter.ts

@@ -68,10 +68,7 @@ export class NotificationPresenter {
         this._disposeRequestPermission.unsubscribe();
         this._disposeshowNotification.unsubscribe();
 
-        this._audio = null;
-        this._disposePlay = null;
-        this._disposeRequestPermission = null;
-        this._disposeshowNotification = null;
+        this._audio.destroy();
     }
 
     playSound(): void {

src/client/script/output/WindowPresenter.ts

@@ -41,14 +41,14 @@ export class WindowPresenter implements EventListenerObject {
     private _domain: DomainState;
     private _disposer: Rx.Subscription;
 
-    private _currenTab: SelectedTab;
+    private _currenTab: SelectedTab | void;
 
     constructor(domain: DomainState) {
         this._domain = domain;
         this._disposer = new Rx.Subscription();
 
         this._disposer.add(AppActionCreator.dispatcher().reload.subscribe(function () {
-            window.onbeforeunload = null;
+            (window as any).onbeforeunload = null;
 
             location.reload();
         }));
@@ -63,7 +63,7 @@ export class WindowPresenter implements EventListenerObject {
             }
         }));
 
-        this._currenTab = null;
+        this._currenTab = undefined;
         this._disposer.add(domain.getCurrentTab().subscribe((tab) => {
             this._currenTab = tab;
         }));
@@ -115,10 +115,6 @@ export class WindowPresenter implements EventListenerObject {
         window.document.documentElement.removeEventListener('keydown', this);
 
         this._disposer.unsubscribe();
-
-        this._currenTab = null;
-        this._disposer = null;
-        this._domain = null;
     }
 
     private _onBeforeUnload(aEvent: Event): string {
@@ -166,10 +162,16 @@ export class WindowPresenter implements EventListenerObject {
 
     handleShortcut(key: string): void {
         const channelList: Array<Channel> = this._domain.networkSet.getChannelList();
-        const currentIndex: Option<ChannelId> = this._domain.currentTab.channelId.map(function(currentId: ChannelId) {
-            return channelList.findIndex(function(channel: Channel){
+        const currentIndex: Option<ChannelId> = this._domain.currentTab.channelId.map(function(currentId: ChannelId): number {
+            const result = channelList.findIndex(function(channel: Channel){
                 return channel.id === currentId;
             });
+            if (result === undefined) {
+                throw new Error('should not be undefined');
+            }
+            else {
+                return result;
+            }
         });
 
         if (currentIndex.isNone) {
@@ -213,4 +215,4 @@ export class WindowPresenter implements EventListenerObject {
         const title = BASE_TITLE + ' - ' + currentName;
         window.document.title = title;
     }
-}
+}

src/client/script/output/context/ConnectSettingContext.ts

@@ -40,7 +40,7 @@ export class ConnectSettingContext implements ViewContext {
 
     private _action: ConnectionActionCreator;
     private _store: ConnectionStore;
-    private _viewDisposer: Rx.Subscription;
+    private _viewDisposer: Rx.Subscription | undefined;
 
     constructor(gateway: MessageGateway) {
         if (!gateway) {
@@ -49,17 +49,13 @@ export class ConnectSettingContext implements ViewContext {
 
         this._action = new ConnectionActionCreator();
         this._store = new ConnectionStore(this._action.dispatcher(), gateway);
-        this._viewDisposer = null;
+        this._viewDisposer = undefined;
     }
 
     private _destroy(): void {
-        this._viewDisposer.unsubscribe();
+        this._viewDisposer!.unsubscribe();
         this._store.dispose();
         this._action.dispose();
-
-        this._viewDisposer = null;
-        this._store = null;
-        this._action = null;
     }
 
     onActivate(mountpoint: Element): void {

src/client/script/output/context/SidebarContext.ts

@@ -36,19 +36,16 @@ import {ViewContext} from './ViewContext';
 export class SidebarContext implements ViewContext {
 
     private _viewmodel: SidebarStore;
-    private _viewDisposer: Rx.Subscription;
+    private _viewDisposer: Rx.Subscription | void;
 
     constructor(domain: DomainState) {
         this._viewmodel = new SidebarStore(domain);
-        this._viewDisposer = null;
+        this._viewDisposer = undefined;
     }
 
     private _destroy(): void {
         this._viewDisposer.unsubscribe();
         this._viewmodel.dispose();
-
-        this._viewDisposer = null;
-        this._viewmodel = null;
     }
 
     onActivate(mountpoint: Element): void {

src/client/script/output/view/AppView.ts

@@ -47,7 +47,7 @@ class AppViewModel {
 
 export class AppView {
 
-    private _element: Element;
+    private _element: Element | void;
     private _vm: AppViewModel;
     private _disposer: Rx.Subscription;
 
@@ -67,7 +67,7 @@ export class AppView {
     }
 
     destroy(): void {
-        this._element = null;
+        this._element = undefined;
         this._vm.destroy();
         this._disposer.unsubscribe();
     }
@@ -102,7 +102,7 @@ export class AppView {
     }
 
     private _handleClickEvent(): Rx.Subscription {
-        return Rx.Observable.fromEvent<Element>(this._element, 'click', (event: UIEvent) => event.target as Element)
+        return Rx.Observable.fromEvent<Element>(this._element!, 'click', (event: UIEvent) => event.target as Element)
             .filter((target: Element): boolean => (target.localName === 'button'))
             .subscribe((target: Element) => {
                 if (target.classList.contains('lt')) {

src/client/script/output/view/GeneralSettingView.ts

@@ -69,7 +69,7 @@ export class GeneralSettingView implements EventListenerObject {
         const name = target.getAttribute('name');
         const value = (target as HTMLInputElement).checked;
 
-        SettingActionCreator.setOption(name, value);
+        SettingActionCreator.setOption(name!, value);
 
         if (value && target.getAttribute('id') === 'badge') {
             NotificationActionCreator.requestPermission();

src/client/script/output/view/InputBoxView.ts

@@ -61,7 +61,7 @@ export class InputBoxView {
     private _disposer: Rx.Subscription;
 
     private _inputVal: InputValue;
-    private _lastSuggestionCache: Array<string>;
+    private _lastSuggestionCache: Array<string> | undefined;
     private _isSuggestion: boolean;
 
     constructor(domain: DomainState, element: Element) {
@@ -99,7 +99,7 @@ export class InputBoxView {
         }));
 
         this._inputVal = new InputValue('', new None<number>());
-        this._lastSuggestionCache = null;
+        this._lastSuggestionCache = undefined;
         this._isSuggestion = false;
 
         this._init();
@@ -201,16 +201,16 @@ export class InputBoxView {
         }
         else {
             const newly = this._inputVal.suggstedIndex.unwrap() + 1;
-            index = (newly > (this._lastSuggestionCache.length - 1)) ? 0 : newly;
+            index = (newly > (this._lastSuggestionCache!.length - 1)) ? 0 : newly;
         }
 
-        if (this._lastSuggestionCache.length === 0) {
+        if (this._lastSuggestionCache!.length === 0) {
             return;
         }
 
         this._inputVal = new InputValue(this._inputVal.actual, new Some(index));
         this._isSuggestion = true;
-        this._textInput.value = this._lastSuggestionCache[index];
+        this._textInput.value = this._lastSuggestionCache![index];
         this._isSuggestion = false;
     }
 
@@ -230,7 +230,7 @@ export class InputBoxView {
 
         const current = this._textInput.value;
         this._inputVal = new InputValue(current, new None<number>());
-        this._lastSuggestionCache = null;
+        this._lastSuggestionCache = undefined;
     }
 
     private _createSuggestion(value: string): Array<string> {