Add eslint type assertions rule

Fixes #3359

.eslintrc.json

@@ -47,6 +47,7 @@
         "readonly": "generic"
       }
     ],
+    "@typescript-eslint/consistent-type-assertions": "warn",
     "@typescript-eslint/consistent-type-definitions": "warn",
     "@typescript-eslint/explicit-function-return-type": [
       "warn",

addons/xterm-addon-serialize/test/SerializeAddon.api.ts

@@ -487,9 +487,9 @@ function newArray<T>(initial: T | ((index: number) => T), count: number): T[] {
   const array: T[] = new Array<T>(count);
   for (let i = 0; i < array.length; i++) {
     if (typeof initial === 'function') {
-      array[i] = (<(index: number) => T>initial)(i);
+      array[i] = (initial as (index: number) => T)(i);
     } else {
-      array[i] = <T>initial;
+      array[i] = initial as T;
     }
   }
   return array;

addons/xterm-addon-webgl/src/WebglAddon.ts

@@ -24,9 +24,9 @@ export class WebglAddon implements ITerminalAddon {
       throw new Error('Cannot activate WebglAddon before Terminal.open');
     }
     this._terminal = terminal;
-    const renderService: IRenderService = (<any>terminal)._core._renderService;
-    const characterJoinerService: ICharacterJoinerService = (<any>terminal)._core._characterJoinerService;
-    const colors: IColorSet = (<any>terminal)._core._colorManager.colors;
+    const renderService: IRenderService = (terminal as any)._core._renderService;
+    const characterJoinerService: ICharacterJoinerService = (terminal as any)._core._characterJoinerService;
+    const colors: IColorSet = (terminal as any)._core._colorManager.colors;
     this._renderer = new WebglRenderer(terminal, colors, characterJoinerService, this._preserveDrawingBuffer);
     this._renderer.onContextLoss(() => this._onContextLoss.fire());
     renderService.setRenderer(this._renderer);

src/browser/AccessibilityManager.ts

@@ -112,7 +112,7 @@ export class AccessibilityManager extends Disposable {
   }
 
   private _onBoundaryFocus(e: FocusEvent, position: BoundaryPosition): void {
-    const boundaryElement = <HTMLElement>e.target;
+    const boundaryElement = e.target as HTMLElement;
     const beforeBoundaryElement = this._rowElements[position === BoundaryPosition.TOP ? 1 : this._rowElements.length - 2];
 
     // Don't scroll if the buffer top has reached the end in that direction

src/browser/ColorManager.test.ts

@@ -17,7 +17,7 @@ describe('ColorManager', () => {
     dom = new jsdom.JSDOM('');
     window = dom.window;
     document = window.document;
-    (<any>window).HTMLCanvasElement.prototype.getContext = () => ({
+    (window as any).HTMLCanvasElement.prototype.getContext = () => ({
       createLinearGradient(): any {
         return null;
       },
@@ -36,7 +36,7 @@ describe('ColorManager', () => {
       for (const key of Object.keys(cm.colors)) {
         if (key !== 'ansi' && key !== 'contrastCache') {
           // A #rrggbb or rgba(...)
-          assert.ok((<any>cm.colors)[key].css.length >= 7);
+          assert.ok((cm.colors as any)[key].css.length >= 7);
         }
       }
       assert.equal(cm.colors.ansi.length, 256);

src/browser/Linkifier.test.ts

@@ -174,7 +174,7 @@ describe('Linkifier', () => {
             assert.equal(mouseZoneManager.zones[0].y1, 1);
             assert.equal(mouseZoneManager.zones[0].y2, 1);
             // Fires done()
-            mouseZoneManager.zones[0].clickCallback(<any>{});
+            mouseZoneManager.zones[0].clickCallback({} as any);
           }
         });
         linkifier.linkifyRows();

src/browser/Linkifier.ts

@@ -89,7 +89,7 @@ export class Linkifier implements ILinkifier {
     if (this._rowsTimeoutId) {
       clearTimeout(this._rowsTimeoutId);
     }
-    this._rowsTimeoutId = <number><any>setTimeout(() => this._linkifyRows(), Linkifier._timeBeforeLatency);
+    this._rowsTimeoutId = window.setTimeout(() => this._linkifyRows(), Linkifier._timeBeforeLatency);
   }
 
   /**

src/browser/Terminal.test.ts

@@ -29,10 +29,10 @@ describe('Terminal', () => {
   beforeEach(() => {
     term = new TestTerminal(termOptions);
     term.refresh = () => { };
-    (<any>term).renderer = new MockRenderer();
+    (term as any).renderer = new MockRenderer();
     term.viewport = new MockViewport();
-    (<any>term)._compositionHelper = new MockCompositionHelper();
-    (<any>term).element = {
+    (term as any)._compositionHelper = new MockCompositionHelper();
+    (term as any).element = {
       classList: {
         toggle: () => { },
         remove: () => { }
@@ -86,12 +86,12 @@ describe('Terminal', () => {
         assert.equal(e.domEvent instanceof Object, true);
         done();
       });
-      const evKeyPress = <KeyboardEvent>{
+      const evKeyPress = {
         preventDefault: () => { },
         stopPropagation: () => { },
         type: 'keypress',
         keyCode: 13
-      };
+      } as KeyboardEvent;
       term.keyPress(evKeyPress);
     });
     it('should fire a key event after a keydown DOM event', (done) => {
@@ -100,13 +100,13 @@ describe('Terminal', () => {
         assert.equal(e.domEvent instanceof Object, true);
         done();
       });
-      (<any>term).textarea = { value: '' };
-      const evKeyDown = <KeyboardEvent>{
+      (term as any).textarea = { value: '' };
+      const evKeyDown = {
         preventDefault: () => { },
         stopPropagation: () => { },
         type: 'keydown',
         keyCode: 13
-      };
+      } as KeyboardEvent;
       term.keyDown(evKeyDown);
     });
     it('should fire the onResize event', (done) => {
@@ -140,18 +140,18 @@ describe('Terminal', () => {
   });
 
   describe('attachCustomKeyEventHandler', () => {
-    const evKeyDown = <KeyboardEvent>{
+    const evKeyDown = {
       preventDefault: () => { },
       stopPropagation: () => { },
       type: 'keydown',
       keyCode: 77
-    };
-    const evKeyPress = <KeyboardEvent>{
+    } as KeyboardEvent;
+    const evKeyPress = {
       preventDefault: () => { },
       stopPropagation: () => { },
       type: 'keypress',
       keyCode: 77
-    };
+    } as KeyboardEvent;
 
     beforeEach(() => {
       term.clearSelection = () => { };
@@ -374,13 +374,13 @@ describe('Terminal', () => {
 
     describe('keyPress', () => {
       it('should scroll down, when a key is pressed and terminal is scrolled up', () => {
-        const event = <KeyboardEvent>{
+        const event = {
           type: 'keydown',
           key: 'a',
           keyCode: 65,
           preventDefault: () => { },
           stopPropagation: () => { }
-        };
+        } as KeyboardEvent;
 
         term.buffer.ydisp = 0;
         term.buffer.ybase = 40;
@@ -403,7 +403,7 @@ describe('Terminal', () => {
         assert.equal(term.buffer.ydisp, startYDisp);
         term.scrollLines(-1);
         assert.equal(term.buffer.ydisp, startYDisp - 1);
-        term.keyPress(<KeyboardEvent>{ keyCode: 0 });
+        term.keyPress({ keyCode: 0 });
         assert.equal(term.buffer.ydisp, startYDisp - 1);
       });
     });

src/browser/Terminal.ts

@@ -72,7 +72,7 @@ export class Terminal extends CoreTerminal implements ITerminal {
 
   // private _visualBellTimer: number;
 
-  public browser: IBrowser = <any>Browser;
+  public browser: IBrowser = Browser as any;
 
   // TODO: We should remove options once components adopt optionsService
   public get options(): IInitializedTerminalOptions { return this.optionsService.options; }
@@ -601,7 +601,7 @@ export class Terminal extends CoreTerminal implements ITerminal {
 
       let but: CoreMouseButton;
       let action: CoreMouseAction | undefined;
-      switch ((<any>ev).overrideType || ev.type) {
+      switch ((ev as any).overrideType || ev.type) {
         case 'mousemove':
           action = CoreMouseAction.MOVE;
           if (ev.buttons === undefined) {

src/browser/TestUtils.test.ts

@@ -153,7 +153,7 @@ export class MockTerminal implements ITerminal {
   public textarea!: HTMLTextAreaElement;
   public rows!: number;
   public cols!: number;
-  public browser: IBrowser = <any>Browser;
+  public browser: IBrowser = Browser as any;
   public writeBuffer!: string[];
   public children!: HTMLElement[];
   public cursorHidden!: boolean;

src/browser/input/CompositionHelper.test.ts

@@ -49,7 +49,7 @@ describe('CompositionHelper', () => {
     it('Should insert simple characters', (done) => {
       // First character 'ㅇ'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent><CompositionEvent>{ data: 'ㅇ' });
+      compositionHelper.compositionupdate({ data: 'ㅇ' });
       textarea.value = 'ㅇ';
       setTimeout(() => { // wait for any textarea updates
         compositionHelper.compositionend();
@@ -57,7 +57,7 @@ describe('CompositionHelper', () => {
           assert.equal(handledText, 'ㅇ');
           // Second character 'ㅇ'
           compositionHelper.compositionstart();
-          compositionHelper.compositionupdate(<CompositionEvent><CompositionEvent>{ data: 'ㅇ' });
+          compositionHelper.compositionupdate({ data: 'ㅇ' });
           textarea.value = 'ㅇㅇ';
           setTimeout(() => { // wait for any textarea updates
             compositionHelper.compositionend();
@@ -73,13 +73,13 @@ describe('CompositionHelper', () => {
     it('Should insert complex characters', (done) => {
       // First character '앙'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent>{ data: 'ㅇ' });
+      compositionHelper.compositionupdate({ data: 'ㅇ' });
       textarea.value = 'ㅇ';
       setTimeout(() => { // wait for any textarea updates
-        compositionHelper.compositionupdate(<CompositionEvent>{ data: '아' });
+        compositionHelper.compositionupdate({ data: '아' });
         textarea.value = '아';
         setTimeout(() => { // wait for any textarea updates
-          compositionHelper.compositionupdate(<CompositionEvent>{ data: '앙' });
+          compositionHelper.compositionupdate({ data: '앙' });
           textarea.value = '앙';
           setTimeout(() => { // wait for any textarea updates
             compositionHelper.compositionend();
@@ -87,13 +87,13 @@ describe('CompositionHelper', () => {
               assert.equal(handledText, '앙');
               // Second character '앙'
               compositionHelper.compositionstart();
-              compositionHelper.compositionupdate(<CompositionEvent>{ data: 'ㅇ' });
+              compositionHelper.compositionupdate({ data: 'ㅇ' });
               textarea.value = '앙ㅇ';
               setTimeout(() => { // wait for any textarea updates
-                compositionHelper.compositionupdate(<CompositionEvent>{ data: '아' });
+                compositionHelper.compositionupdate({ data: '아' });
                 textarea.value = '앙아';
                 setTimeout(() => { // wait for any textarea updates
-                  compositionHelper.compositionupdate(<CompositionEvent>{ data: '앙' });
+                  compositionHelper.compositionupdate({ data: '앙' });
                   textarea.value = '앙앙';
                   setTimeout(() => { // wait for any textarea updates
                     compositionHelper.compositionend();
@@ -113,19 +113,19 @@ describe('CompositionHelper', () => {
     it('Should insert complex characters that change with following character', (done) => {
       // First character '아'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent>{ data: 'ㅇ' });
+      compositionHelper.compositionupdate({ data: 'ㅇ' });
       textarea.value = 'ㅇ';
       setTimeout(() => { // wait for any textarea updates
-        compositionHelper.compositionupdate(<CompositionEvent>{ data: '아' });
+        compositionHelper.compositionupdate({ data: '아' });
         textarea.value = '아';
         setTimeout(() => { // wait for any textarea updates
           // Start second character '아' in first character
-          compositionHelper.compositionupdate(<CompositionEvent>{ data: '앙' });
+          compositionHelper.compositionupdate({ data: '앙' });
           textarea.value = '앙';
           setTimeout(() => { // wait for any textarea updates
             compositionHelper.compositionend();
             compositionHelper.compositionstart();
-            compositionHelper.compositionupdate(<CompositionEvent>{ data: '아' });
+            compositionHelper.compositionupdate({ data: '아' });
             textarea.value = '아아';
             setTimeout(() => { // wait for any textarea updates
               compositionHelper.compositionend();
@@ -142,14 +142,14 @@ describe('CompositionHelper', () => {
     it('Should insert multi-characters compositions', (done) => {
       // First character 'だ'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent>{ data: 'd' });
+      compositionHelper.compositionupdate({ data: 'd' });
       textarea.value = 'd';
       setTimeout(() => { // wait for any textarea updates
-        compositionHelper.compositionupdate(<CompositionEvent>{ data: 'だ' });
+        compositionHelper.compositionupdate({ data: 'だ' });
         textarea.value = 'だ';
         setTimeout(() => { // wait for any textarea updates
           // Second character 'あ'
-          compositionHelper.compositionupdate(<CompositionEvent>{ data: 'だあ' });
+          compositionHelper.compositionupdate({ data: 'だあ' });
           textarea.value = 'だあ';
           setTimeout(() => { // wait for any textarea updates
             compositionHelper.compositionend();
@@ -165,18 +165,18 @@ describe('CompositionHelper', () => {
     it('Should insert multi-character compositions that are converted to other characters with the same length', (done) => {
       // First character 'だ'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent>{ data: 'd' });
+      compositionHelper.compositionupdate({ data: 'd' });
       textarea.value = 'd';
       setTimeout(() => { // wait for any textarea updates
-        compositionHelper.compositionupdate(<CompositionEvent>{ data: 'だ' });
+        compositionHelper.compositionupdate({ data: 'だ' });
         textarea.value = 'だ';
         setTimeout(() => { // wait for any textarea updates
           // Second character 'ー'
-          compositionHelper.compositionupdate(<CompositionEvent>{ data: 'だー' });
+          compositionHelper.compositionupdate({ data: 'だー' });
           textarea.value = 'だー';
           setTimeout(() => { // wait for any textarea updates
             // Convert to katakana 'ダー'
-            compositionHelper.compositionupdate(<CompositionEvent>{ data: 'ダー' });
+            compositionHelper.compositionupdate({ data: 'ダー' });
             textarea.value = 'ダー';
             setTimeout(() => { // wait for any textarea updates
               compositionHelper.compositionend();
@@ -193,18 +193,18 @@ describe('CompositionHelper', () => {
     it('Should insert multi-character compositions that are converted to other characters with different lengths', (done) => {
       // First character 'い'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent>{ data: 'い' });
+      compositionHelper.compositionupdate({ data: 'い' });
       textarea.value = 'い';
       setTimeout(() => { // wait for any textarea updates
         // Second character 'ま'
-        compositionHelper.compositionupdate(<CompositionEvent>{ data: 'いm' });
+        compositionHelper.compositionupdate({ data: 'いm' });
         textarea.value = 'いm';
         setTimeout(() => { // wait for any textarea updates
-          compositionHelper.compositionupdate(<CompositionEvent>{ data: 'いま' });
+          compositionHelper.compositionupdate({ data: 'いま' });
           textarea.value = 'いま';
           setTimeout(() => { // wait for any textarea updates
             // Convert to kanji '今'
-            compositionHelper.compositionupdate(<CompositionEvent>{ data: '今' });
+            compositionHelper.compositionupdate({ data: '今' });
             textarea.value = '今';
             setTimeout(() => { // wait for any textarea updates
               compositionHelper.compositionend();
@@ -221,7 +221,7 @@ describe('CompositionHelper', () => {
     it('Should insert non-composition characters input immediately after composition characters', (done) => {
       // First character 'ㅇ'
       compositionHelper.compositionstart();
-      compositionHelper.compositionupdate(<CompositionEvent>{ data: 'ㅇ' });
+      compositionHelper.compositionupdate({ data: 'ㅇ' });
       textarea.value = 'ㅇ';
       setTimeout(() => { // wait for any textarea updates
         compositionHelper.compositionend();

src/browser/input/CompositionHelper.ts

@@ -69,7 +69,7 @@ export class CompositionHelper {
    * Handles the compositionupdate event, updating the composition view.
    * @param ev The event.
    */
-  public compositionupdate(ev: CompositionEvent): void {
+  public compositionupdate(ev: Pick<CompositionEvent, 'data'>): void {
     this._compositionView.textContent = ev.data;
     this.updateCompositionElements();
     setTimeout(() => {

src/browser/public/AddonManager.ts

@@ -31,7 +31,7 @@ export class AddonManager implements IDisposable {
     };
     this._addons.push(loadedAddon);
     instance.dispose = () => this._wrappedAddonDispose(loadedAddon);
-    instance.activate(<any>terminal);
+    instance.activate(terminal as any);
   }
 
   private _wrappedAddonDispose(loadedAddon: ILoadedAddon): void {

src/browser/public/Terminal.ts

@@ -280,7 +280,7 @@ class BufferLineApiView implements IBufferLineApi {
     }
 
     if (cell) {
-      this._line.loadCell(x, <ICellData>cell);
+      this._line.loadCell(x, cell as ICellData);
       return cell;
     }
     return this._line.loadCell(x, new CellData());

src/browser/renderer/atlas/CharAtlasUtils.ts

@@ -10,7 +10,7 @@ import { ITerminalOptions } from 'common/services/Services';
 
 export function generateConfig(scaledCharWidth: number, scaledCharHeight: number, options: ITerminalOptions, colors: IColorSet): ICharAtlasConfig {
   // null out some fields that don't matter
-  const clonedColors = <IPartialColorSet>{
+  const clonedColors: IPartialColorSet = {
     foreground: colors.foreground,
     background: colors.background,
     cursor: undefined,

src/browser/renderer/dom/DomRenderer.ts

@@ -387,7 +387,7 @@ export class DomRenderer extends Disposable implements IRenderer {
       if (!row) {
         return;
       }
-      const span = <HTMLElement>row.children[x];
+      const span = row.children[x] as HTMLElement;
       if (span) {
         span.style.textDecoration = enabled ? 'underline' : 'none';
       }

src/browser/services/CharacterJoinerService.test.ts

@@ -270,7 +270,7 @@ function lineData(data: IPartialLineData[]): IBufferLine {
   const tline = new BufferLine(0);
   for (let i = 0; i < data.length; ++i) {
     const line = data[i][0];
-    const attr = <number>(data[i][1] || 0);
+    const attr = (data[i][1] || 0) as number;
     const offset = tline.length;
     tline.resize(tline.length + line.split('').length, CellData.fromCharData([0, '', 0, 0]));
     line.split('').map((char, idx) => tline.setCell(idx + offset, CellData.fromCharData([attr, char, 1, char.charCodeAt(0)])));

src/browser/services/SelectionService.ts

@@ -133,8 +133,8 @@ export class SelectionService extends Disposable implements ISelectionService {
     super();
 
     // Init listeners
-    this._mouseMoveListener = event => this._onMouseMove(<MouseEvent>event);
-    this._mouseUpListener = event => this._onMouseUp(<MouseEvent>event);
+    this._mouseMoveListener = event => this._onMouseMove(event as MouseEvent);
+    this._mouseUpListener = event => this._onMouseUp(event as MouseEvent);
     this._coreService.onUserInput(() => {
       if (this.hasSelection) {
         this.clearSelection();

src/browser/services/SoundService.ts

@@ -13,7 +13,7 @@ export class SoundService implements ISoundService {
 
   public static get audioContext(): AudioContext | null {
     if (!SoundService._audioContext) {
-      const audioContextCtor: typeof AudioContext = (<any>window).AudioContext || (<any>window).webkitAudioContext;
+      const audioContextCtor: typeof AudioContext = (window as any).AudioContext || (window as any).webkitAudioContext;
       if (!audioContextCtor) {
         console.warn('Web Audio API is not supported by this browser. Consider upgrading to the latest version');
         return null;

src/common/TestUtils.test.ts

@@ -125,7 +125,7 @@ export class MockOptionsService implements IOptionsService {
   constructor(testOptions?: IPartialTerminalOptions) {
     if (testOptions) {
       for (const key of Object.keys(testOptions)) {
-        this.options[key] = (<any>testOptions)[key];
+        this.options[key] = (testOptions as any)[key];
       }
     }
   }