From efeca49705e12676ba3c9a85b615576f552cf882 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sun, 7 Apr 2019 15:29:37 -0400
Subject: [PATCH 01/12] Mostly implemented buffer API

Part of #1994
---
 src/public/Terminal.ts | 32 +++++++++++++++--
 typings/xterm.d.ts     | 80 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+), 2 deletions(-)

diff --git a/src/public/Terminal.ts b/src/public/Terminal.ts
index 87fcfaef99..bc82d23529 100644
--- a/src/public/Terminal.ts
+++ b/src/public/Terminal.ts
@@ -3,8 +3,8 @@
  * @license MIT
  */
 
-import { Terminal as ITerminalApi, ITerminalOptions, IMarker, IDisposable, ILinkMatcherOptions, ITheme, ILocalizableStrings } from 'xterm';
-import { ITerminal } from '../Types';
+import { Terminal as ITerminalApi, ITerminalOptions, IMarker, IDisposable, ILinkMatcherOptions, ITheme, ILocalizableStrings, IBuffer as IBufferApi, IBufferLine as IBufferLineApi, IBufferCell as IBufferCellApi } from 'xterm';
+import { ITerminal, IBufferLine, IBuffer } from '../Types';
 import { Terminal as TerminalCore } from '../Terminal';
 import * as Strings from '../Strings';
 
@@ -19,6 +19,7 @@ export class Terminal implements ITerminalApi {
   public get textarea(): HTMLTextAreaElement { return this._core.textarea; }
   public get rows(): number { return this._core.rows; }
   public get cols(): number { return this._core.cols; }
+  public get buffer(): IBufferApi { return new BufferApiView(this._core.buffer); }
   public get markers(): IMarker[] { return this._core.markers; }
   public blur(): void {
     this._core.blur();
@@ -158,3 +159,30 @@ export class Terminal implements ITerminalApi {
     return Strings;
   }
 }
+
+class BufferApiView implements IBufferApi {
+  constructor(private _buffer: IBuffer) {}
+
+  public get cursorY(): number { return this._buffer.y; }
+  public get cursorX(): number { return this._buffer.x; }
+  public get viewportY(): number { return this._buffer.ydisp; }
+  public get baseY(): number { return this._buffer.ybase; }
+  public get length(): number { return this._buffer.lines.length; }
+  public getLine(y: number): IBufferLineApi { return new BufferLineApiView(this._buffer.lines.get(y)); }
+}
+
+class BufferLineApiView implements IBufferLineApi {
+  constructor(private _line: IBufferLine) {}
+
+  public get isWrapped(): boolean { return this._line.isWrapped; }
+  public getCell(x: number): IBufferCellApi { return new BufferCellApiView(this._line, x); }
+  public translateToString(trimRight: boolean, startColumn: number, endColumn: number): string {
+    return this._line.translateToString(trimRight, startColumn, endColumn);
+  }
+}
+
+class BufferCellApiView implements IBufferCellApi {
+  constructor(private _line: IBufferLine, private _x: number) {}
+  public get char(): string { return this._line.getString(this._x); }
+  public get width(): number { return this._line.getWidth(this._x); }
+}
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index ec647a10f5..429ad7e382 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -347,6 +347,13 @@ declare module 'xterm' {
      */
     readonly cols: number;
 
+    /**
+     * (EXPERIMENTAL) The terminal's current buffer, note that this might be
+     * either the normal buffer or the alt buffer depending on what's running in
+     * the terminal.
+     */
+    readonly buffer: IBuffer;
+
     /**
      * (EXPERIMENTAL) Get all markers registered against the buffer. If the alt
      * buffer is active this will always return [].
@@ -772,4 +779,77 @@ declare module 'xterm' {
      */
     static applyAddon(addon: any): void;
   }
+
+  interface IBuffer {
+    /**
+     * The y position of the cursor. This ranges between `0` (when the
+     * cursor is at baseY) and `Terminal.rows - 1` (when the cursor is on the
+     * last row).
+     */
+    readonly cursorY: number;
+
+    /**
+     * The x position of the cursor. This ranges between `0` (left side) and
+     * `Terminal.cols - 1` (right side).
+     */
+    readonly cursorX: number;
+
+    /**
+     * The line within the buffer where the top of the viewport is.
+     */
+    readonly viewportY: number;
+
+    /**
+     * The line within the buffer where the top of the bottom page is (when
+     * fully scrolled down);
+     */
+    readonly baseY: number;
+
+    /**
+     * The amount of lines in the buffer.
+     */
+    readonly length: number;
+
+    /**
+     * Gets a line from the buffer.
+     *
+     * @param y The line index to get.
+     */
+    getLine(y: number): IBufferLine;
+  }
+
+  interface IBufferLine {
+    /**
+     * Whether the line is wrapped from the previous line.
+     */
+    readonly isWrapped: boolean;
+
+    /**
+     * Gets a cell from the line.
+     *
+     * @param x The character index to get.
+     */
+    getCell(x: number): IBufferCell;
+
+    /**
+     * Gets the line
+     */
+    translateToString(trimRight: boolean, startColumn: number, endColumn: number): string;
+  }
+
+  interface IBufferCell {
+    /**
+     * The character within the cell.
+     */
+    readonly char: string;
+
+    /**
+     * The width of the character. Some examples:
+     *
+     * - This is `1` for most cells.
+     * - This is `2` for wide character like CJK glyphs.
+     * - This is `0` for cells immediately following cells with a width of `2`.
+     */
+    readonly width: number;
+  }
 }

From b55bedc6af73f2eeeb0472f4b0699ceba3e59a90 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Tue, 9 Apr 2019 21:29:08 -0700
Subject: [PATCH 02/12] Add terminal API interface to Types.ts

This is needed since the API/public buffer now differs from the TerminalCore's
---
 src/Types.ts                    | 43 +++++++++++++++++++++++++++++++--
 src/renderer/dom/DomRenderer.ts |  4 +--
 typings/xterm.d.ts              |  2 +-
 3 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/src/Types.ts b/src/Types.ts
index 6e0108aefc..1fa78824f1 100644
--- a/src/Types.ts
+++ b/src/Types.ts
@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { Terminal as PublicTerminal, ITerminalOptions as IPublicTerminalOptions, IEventEmitter, IDisposable } from 'xterm';
+import { ITerminalOptions as IPublicTerminalOptions, IEventEmitter, IDisposable, IMarker } from 'xterm';
 import { IColorSet, IRenderer } from './renderer/Types';
 import { IMouseZoneManager } from './ui/Types';
 import { ICharset } from './core/Types';
@@ -202,7 +202,7 @@ export interface ILinkHoverEvent {
   fg: number;
 }
 
-export interface ITerminal extends PublicTerminal, IElementAccessor, IBufferAccessor, ILinkifierAccessor {
+export interface ITerminal extends IPublicTerminal, IElementAccessor, IBufferAccessor, ILinkifierAccessor {
   screenElement: HTMLElement;
   selectionManager: ISelectionManager;
   charMeasure: ICharMeasure;
@@ -231,6 +231,45 @@ export interface ITerminal extends PublicTerminal, IElementAccessor, IBufferAcce
   showCursor(): void;
 }
 
+export interface IPublicTerminal extends IDisposable, IEventEmitter {
+    textarea: HTMLTextAreaElement;
+    rows: number;
+    cols: number;
+    buffer: IBuffer;
+    markers: IMarker[];
+    blur(): void;
+    focus(): void;
+    resize(columns: number, rows: number): void;
+    writeln(data: string): void;
+    open(parent: HTMLElement): void;
+    attachCustomKeyEventHandler(customKeyEventHandler: (event: KeyboardEvent) => boolean): void;
+    addCsiHandler(flag: string, callback: (params: number[], collect: string) => boolean): IDisposable;
+    addOscHandler(ident: number, callback: (data: string) => boolean): IDisposable;
+    registerLinkMatcher(regex: RegExp, handler: (event: MouseEvent, uri: string) => void, options?: ILinkMatcherOptions): number;
+    deregisterLinkMatcher(matcherId: number): void;
+    registerCharacterJoiner(handler: (text: string) => [number, number][]): number;
+    deregisterCharacterJoiner(joinerId: number): void;
+    addMarker(cursorYOffset: number): IMarker;
+    hasSelection(): boolean;
+    getSelection(): string;
+    clearSelection(): void;
+    selectAll(): void;
+    selectLines(start: number, end: number): void;
+    dispose(): void;
+    destroy(): void;
+    scrollLines(amount: number): void;
+    scrollPages(pageCount: number): void;
+    scrollToTop(): void;
+    scrollToBottom(): void;
+    scrollToLine(line: number): void;
+    clear(): void;
+    write(data: string): void;
+    getOption(key: string): any;
+    setOption(key: string, value: any): void;
+    refresh(start: number, end: number): void;
+    reset(): void;
+}
+
 export interface IBufferAccessor {
   buffer: IBuffer;
 }
diff --git a/src/renderer/dom/DomRenderer.ts b/src/renderer/dom/DomRenderer.ts
index 78ccc620e8..c4da6710c3 100644
--- a/src/renderer/dom/DomRenderer.ts
+++ b/src/renderer/dom/DomRenderer.ts
@@ -151,8 +151,8 @@ export class DomRenderer extends EventEmitter implements IRenderer {
         `${this._terminalSelector} .${ROW_CONTAINER_CLASS} {` +
         ` color: ${this.colorManager.colors.foreground.css};` +
         ` background-color: ${this.colorManager.colors.background.css};` +
-        ` font-family: ${this._terminal.getOption('fontFamily')};` +
-        ` font-size: ${this._terminal.getOption('fontSize')}px;` +
+        ` font-family: ${this._terminal.options.fontFamily};` +
+        ` font-size: ${this._terminal.options.fontSize}px;` +
         `}`;
     // Text styles
     styles +=
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 429ad7e382..3a656eab2d 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -275,7 +275,7 @@ declare module 'xterm' {
      * A callback that fires when the mouse leaves a link. Note that this can
      * happen even when tooltipCallback hasn't fired for the link yet.
      */
-    leaveCallback?: (event: MouseEvent, uri: string) => boolean | void;
+    leaveCallback?: () => void;
 
     /**
      * The priority of the link matcher, this defines the order in which the link

From 5362ea195ce81ce2707540473c5b7d9d7f4f0eba Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Wed, 10 Apr 2019 00:24:50 -0700
Subject: [PATCH 03/12] Add first API test

---
 src/Terminal.integration.ts | 30 ++++++++++++++++++++++++++++++
 src/public/Terminal.ts      |  2 +-
 typings/xterm.d.ts          |  2 +-
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/Terminal.integration.ts b/src/Terminal.integration.ts
index 100430066c..e0dad37793 100644
--- a/src/Terminal.integration.ts
+++ b/src/Terminal.integration.ts
@@ -13,6 +13,7 @@ import * as path from 'path';
 import * as pty from 'node-pty';
 import { assert } from 'chai';
 import { Terminal } from './Terminal';
+import { Terminal as PublicTerminal } from './public/Terminal';
 import { WHITESPACE_CELL_CHAR } from './Buffer';
 import { IViewport } from './Types';
 import { CellData } from './BufferLine';
@@ -78,6 +79,35 @@ function terminalToString(term: Terminal): string {
   return result;
 }
 
+describe('API tests', () => {
+  let api: PublicTerminal;
+  let core: TestTerminal;
+
+  // expect files need terminal at 80x25!
+  const INIT_COLS = 80;
+  const INIT_ROWS = 25;
+
+  beforeEach(() => {
+    api = new PublicTerminal({ cols: INIT_COLS, rows: INIT_ROWS });
+    core = (api as any)._core;
+    core.innerWrite = () => (core as any)._innerWrite();
+    core.refresh = () => {};
+    core.viewport = <IViewport>{
+      syncScrollArea: () => {}
+    };
+  });
+
+  describe('buffer', () => {
+    it('IBufferLine.getLine', () => {
+      core.writeBuffer.push('abc\n\rdef');
+      core.innerWrite();
+      assert.equal(api.buffer.length, INIT_ROWS);
+      assert.equal(api.buffer.getLine(0).translateToString(true), 'abc');
+      assert.equal(api.buffer.getLine(1).translateToString(true), 'def');
+    });
+  });
+});
+
 // Skip tests on Windows since pty.open isn't supported
 if (os.platform() !== 'win32') {
   const consoleLog = console.log;
diff --git a/src/public/Terminal.ts b/src/public/Terminal.ts
index bc82d23529..35423b80a2 100644
--- a/src/public/Terminal.ts
+++ b/src/public/Terminal.ts
@@ -176,7 +176,7 @@ class BufferLineApiView implements IBufferLineApi {
 
   public get isWrapped(): boolean { return this._line.isWrapped; }
   public getCell(x: number): IBufferCellApi { return new BufferCellApiView(this._line, x); }
-  public translateToString(trimRight: boolean, startColumn: number, endColumn: number): string {
+  public translateToString(trimRight?: boolean, startColumn?: number, endColumn?: number): string {
     return this._line.translateToString(trimRight, startColumn, endColumn);
   }
 }
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 3a656eab2d..7f87cb129f 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -834,7 +834,7 @@ declare module 'xterm' {
     /**
      * Gets the line
      */
-    translateToString(trimRight: boolean, startColumn: number, endColumn: number): string;
+    translateToString(trimRight?: boolean, startColumn?: number, endColumn?: number): string;
   }
 
   interface IBufferCell {

From 16aaf6c58c5209e879343996de6d0130c6cd3043 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Fri, 10 May 2019 21:08:06 -0700
Subject: [PATCH 04/12] Fix build

---
 src/Types.ts | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Types.ts b/src/Types.ts
index a6451cfdd1..5c276bf2d5 100644
--- a/src/Types.ts
+++ b/src/Types.ts
@@ -227,6 +227,15 @@ export interface IPublicTerminal extends IDisposable, IEventEmitter {
     cols: number;
     buffer: IBuffer;
     markers: IMarker[];
+    onCursorMove: IEvent<void>;
+    onData: IEvent<string>;
+    onKey: IEvent<{ key: string, domEvent: KeyboardEvent }>;
+    onLineFeed: IEvent<void>;
+    onScroll: IEvent<number>;
+    onSelectionChange: IEvent<void>;
+    onRender: IEvent<{ start: number, end: number }>;
+    onResize: IEvent<{ cols: number, rows: number }>;
+    onTitleChange: IEvent<string>;
     blur(): void;
     focus(): void;
     resize(columns: number, rows: number): void;

From eb6deb67f9273e11ac36108d1df2ab4d0387aed8 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 10:10:31 -0700
Subject: [PATCH 05/12] Fix build issues

---
 src/Terminal.integration.ts | 1 -
 src/public/Terminal.ts      | 3 ++-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Terminal.integration.ts b/src/Terminal.integration.ts
index 459d84aac7..5e12d2a308 100644
--- a/src/Terminal.integration.ts
+++ b/src/Terminal.integration.ts
@@ -13,7 +13,6 @@ import * as path from 'path';
 import * as pty from 'node-pty';
 import { assert } from 'chai';
 import { Terminal } from './Terminal';
-import { Terminal as PublicTerminal } from './public/Terminal';
 import { IViewport } from './Types';
 import { CellData, WHITESPACE_CELL_CHAR } from './core/buffer/BufferLine';
 
diff --git a/src/public/Terminal.ts b/src/public/Terminal.ts
index eb3809b171..ee623ca334 100644
--- a/src/public/Terminal.ts
+++ b/src/public/Terminal.ts
@@ -4,7 +4,8 @@
  */
 
 import { Terminal as ITerminalApi, ITerminalOptions, IMarker, IDisposable, ILinkMatcherOptions, ITheme, ILocalizableStrings, IBuffer as IBufferApi, IBufferLine as IBufferLineApi, IBufferCell as IBufferCellApi } from 'xterm';
-import { ITerminal, IBufferLine, IBuffer } from '../Types';
+import { ITerminal, IBuffer } from '../Types';
+import { IBufferLine } from '../core/Types';
 import { Terminal as TerminalCore } from '../Terminal';
 import * as Strings from '../Strings';
 import { IEvent } from '../common/EventEmitter2';

From bce2eae66f771ae4b10815b3872f3c2b89b2c8c2 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 10:15:29 -0700
Subject: [PATCH 06/12] Update yarn.lock

---
 yarn.lock | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 113 insertions(+), 2 deletions(-)

diff --git a/yarn.lock b/yarn.lock
index 440aa4f826..e14ad3a1a2 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -69,6 +69,13 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-6.0.108.tgz#852e8496bcfc5e74cae83a5eb3b30e5661e9b7b9"
   integrity sha512-5q14jNJCPW+Iwk6Y1JxtA7T5ov1aVRS2VA2PvRgFMZtCjoIo8WT1WO56dSV0MSiHR7BEoe2QNuXigBQNqbWdAw==
 
+"@types/puppeteer@^1.12.4":
+  version "1.12.4"
+  resolved "https://registry.yarnpkg.com/@types/puppeteer/-/puppeteer-1.12.4.tgz#8388efdb0b30a54a7e7c4831ca0d709191d77ff1"
+  integrity sha512-aaGbJaJ9TuF9vZfTeoh876sBa+rYJWPwtsmHmYr28pGr42ewJnkDTq2aeSKEmS39SqUdkwLj73y/d7rBSp7mDQ==
+  dependencies:
+    "@types/node" "*"
+
 "@types/tapable@*":
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/@types/tapable/-/tapable-1.0.4.tgz#b4ffc7dc97b498c969b360a41eee247f82616370"
@@ -314,6 +321,13 @@ acorn@^5.6.2:
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.2.tgz#91fa871883485d06708800318404e72bfb26dcc5"
   integrity sha512-cJrKCNcr2kv8dlDnbw+JPUGjHZzo4myaxOLmpOX8a+rgX94YeTcTMv/LFJUSByRpc+i4GgVnnhLxvMu/2Y+rqw==
 
+agent-base@^4.1.0:
+  version "4.2.1"
+  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-4.2.1.tgz#d89e5999f797875674c07d87f260fc41e83e8ca9"
+  integrity sha512-JVwXMr9nHYTUXsBFKUqhJwvlcYU/blreOEUkhNR2eXZIvwd+c+o5V4MgDPKWnMS/56awN3TRzIP+KoPn+roQtg==
+  dependencies:
+    es6-promisify "^5.0.0"
+
 ajv-keywords@^3.1.0:
   version "3.2.0"
   resolved "https://registry.yarnpkg.com/ajv-keywords/-/ajv-keywords-3.2.0.tgz#e86b819c602cf8821ad637413698f1dec021847a"
@@ -1307,7 +1321,7 @@ concat-map@0.0.1:
   resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
   integrity sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=
 
-concat-stream@^1.5.0, concat-stream@^1.6.1:
+concat-stream@1.6.2, concat-stream@^1.5.0, concat-stream@^1.6.1:
   version "1.6.2"
   resolved "https://registry.yarnpkg.com/concat-stream/-/concat-stream-1.6.2.tgz#904bdf194cd3122fc675c77fc4ac3d4ff0fd1a34"
   integrity sha512-27HBghJxjiZtIk3Ycvn/4kbJk/1uZuJFfuPEns6LaEvpvG1f0hTea8lilrouyo9mVc2GWdcEZ8OLoGmSADlrCw==
@@ -1606,7 +1620,7 @@ debug@2.6.8:
   dependencies:
     ms "2.0.0"
 
-debug@2.X, debug@^2.1.2, debug@^2.2.0, debug@^2.3.3, debug@^2.6.8:
+debug@2.6.9, debug@2.X, debug@^2.1.2, debug@^2.2.0, debug@^2.3.3, debug@^2.6.8:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
   integrity sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==
@@ -1620,6 +1634,13 @@ debug@^3.1.0:
   dependencies:
     ms "2.0.0"
 
+debug@^4.1.0:
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-4.1.1.tgz#3b72260255109c6b589cee050f1d516139664791"
+  integrity sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==
+  dependencies:
+    ms "^2.1.1"
+
 debug@~2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/debug/-/debug-2.2.0.tgz#f87057e995b1a1f6ae6a4960664137bc56f039da"
@@ -1938,6 +1959,18 @@ es6-promise@^3.0.2, es6-promise@^3.1.2:
   resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-3.3.1.tgz#a08cdde84ccdbf34d027a1451bc91d4bcd28a613"
   integrity sha1-oIzd6EzNvzTQJ6FFG8kdS80ophM=
 
+es6-promise@^4.0.3:
+  version "4.2.6"
+  resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-4.2.6.tgz#b685edd8258886365ea62b57d30de28fadcd974f"
+  integrity sha512-aRVgGdnmW2OiySVPUC9e6m+plolMAJKjZnQlCwNSuK5yQ0JN61DZSO1X1Ufd1foqWRAlig0rhduTCHe7sVtK5Q==
+
+es6-promisify@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/es6-promisify/-/es6-promisify-5.0.0.tgz#5109d62f3e56ea967c4b63505aef08291c8a5203"
+  integrity sha1-UQnWLz5W6pZ8S2NQWu8IKRyKUgM=
+  dependencies:
+    es6-promise "^4.0.3"
+
 es6-symbol@^3.1.1, es6-symbol@~3.1.1:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/es6-symbol/-/es6-symbol-3.1.1.tgz#bf00ef4fdab6ba1b46ecb7b629b4c7ed5715cc77"
@@ -2174,6 +2207,16 @@ extglob@^2.0.4:
     snapdragon "^0.8.1"
     to-regex "^3.0.1"
 
+extract-zip@^1.6.6:
+  version "1.6.7"
+  resolved "https://registry.yarnpkg.com/extract-zip/-/extract-zip-1.6.7.tgz#a840b4b8af6403264c8db57f4f1a74333ef81fe9"
+  integrity sha1-qEC0uK9kAyZMjbV/Txp0Mz74H+k=
+  dependencies:
+    concat-stream "1.6.2"
+    debug "2.6.9"
+    mkdirp "0.5.1"
+    yauzl "2.4.1"
+
 extsprintf@1.3.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/extsprintf/-/extsprintf-1.3.0.tgz#96918440e3041a7a414f8c52e3c574eb3c3e1e05"
@@ -2213,6 +2256,13 @@ fast-levenshtein@~2.0.4:
   resolved "https://registry.yarnpkg.com/fast-levenshtein/-/fast-levenshtein-2.0.6.tgz#3d8a5c66883a16a30ca8643e851f19baa7797917"
   integrity sha1-PYpcZog6FqMMqGQ+hR8Zuqd5eRc=
 
+fd-slicer@~1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/fd-slicer/-/fd-slicer-1.0.1.tgz#8b5bcbd9ec327c5041bf9ab023fd6750f1177e65"
+  integrity sha1-i1vL2ewyfFBBv5qwI/1nUPEXfmU=
+  dependencies:
+    pend "~1.2.0"
+
 figures@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/figures/-/figures-2.0.0.tgz#3ab1a2d2a62c8bfb431a0c94cb797a2fce27c962"
@@ -3042,6 +3092,14 @@ https-browserify@~0.0.0:
   resolved "https://registry.yarnpkg.com/https-browserify/-/https-browserify-0.0.1.tgz#3f91365cabe60b77ed0ebba24b454e3e09d95a82"
   integrity sha1-P5E2XKvmC3ftDruiS0VOPgnZWoI=
 
+https-proxy-agent@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/https-proxy-agent/-/https-proxy-agent-2.2.1.tgz#51552970fa04d723e04c56d04178c3f92592bbc0"
+  integrity sha512-HPCTS1LW51bcyMYbxUIOO4HEOlQ1/1qRaFWcyxvwaqUS9TY88aoEuHUY33kuAh1YhVVaDQhLZsnPd+XNARWZlQ==
+  dependencies:
+    agent-base "^4.1.0"
+    debug "^3.1.0"
+
 iconv-lite@0.4.19:
   version "0.4.19"
   resolved "https://registry.yarnpkg.com/iconv-lite/-/iconv-lite-0.4.19.tgz#f7468f60135f5e5dad3399c0a81be9a1603a082b"
@@ -4235,6 +4293,11 @@ mime@1.3.4:
   resolved "https://registry.yarnpkg.com/mime/-/mime-1.3.4.tgz#115f9e3b6b3daf2959983cb38f149a2d40eb5d53"
   integrity sha1-EV+eO2s9rylZmDyzjxSaLUDrXVM=
 
+mime@^2.0.3:
+  version "2.4.2"
+  resolved "https://registry.yarnpkg.com/mime/-/mime-2.4.2.tgz#ce5229a5e99ffc313abac806b482c10e7ba6ac78"
+  integrity sha512-zJBfZDkwRu+j3Pdd2aHsR5GfH2jIWhmL1ZzBoc+X+3JEti2hbArWcyJ+1laC1D2/U/W1a/+Cegj0/OnEU2ybjg==
+
 mimic-fn@^1.0.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/mimic-fn/-/mimic-fn-1.2.0.tgz#820c86a39334640e99516928bd03fca88057d022"
@@ -4394,6 +4457,11 @@ ms@2.0.0:
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
   integrity sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g=
 
+ms@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.1.tgz#30a5864eb3ebb0a66f2ebe6d727af06a09d86e0a"
+  integrity sha512-tgp+dl5cGk28utYktBsrFqA7HKgrhgPsg6Z/EfhWI4gl1Hwq8B/GmY/0oXZ6nF8hDVesS/FpnYaD/kOWhYQvyg==
+
 multipipe@^0.1.2:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/multipipe/-/multipipe-0.1.2.tgz#2a8f2ddf70eed564dff2d57f1e1a137d9f05078b"
@@ -5067,6 +5135,11 @@ pbkdf2@^3.0.3:
     safe-buffer "^5.0.1"
     sha.js "^2.4.8"
 
+pend@~1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/pend/-/pend-1.2.0.tgz#7a57eb550a6783f9115331fcf4663d5c8e007a50"
+  integrity sha1-elfrVQpng/kRUzH89GY9XI4AelA=
+
 performance-now@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/performance-now/-/performance-now-2.1.0.tgz#6309f4e0e5fa913ec1c69307ae364b4b377c9e7b"
@@ -5165,6 +5238,11 @@ process@^0.11.10, process@~0.11.0:
   resolved "https://registry.yarnpkg.com/process/-/process-0.11.10.tgz#7332300e840161bda3e69a1d1d91a7d4bc16f182"
   integrity sha1-czIwDoQBYb2j5podHZGn1LwW8YI=
 
+progress@^2.0.1:
+  version "2.0.3"
+  resolved "https://registry.yarnpkg.com/progress/-/progress-2.0.3.tgz#7e8cf8d8f5b8f239c1bc68beb4eb78567d572ef8"
+  integrity sha512-7PiHtLll5LdnKIMw100I+8xJXR5gW2QwWYkT6iJva0bXitZKa/XMrSbdmg3r2Xnaidz9Qumd0VPaMrZlF9V9sA==
+
 promise-inflight@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/promise-inflight/-/promise-inflight-1.0.1.tgz#98472870bf228132fcbdd868129bad12c3c029e3"
@@ -5178,6 +5256,11 @@ proxy-addr@~1.0.10:
     forwarded "~0.1.0"
     ipaddr.js "1.0.5"
 
+proxy-from-env@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/proxy-from-env/-/proxy-from-env-1.0.0.tgz#33c50398f70ea7eb96d21f7b817630a55791c7ee"
+  integrity sha1-M8UDmPcOp+uW0h97gXYwpVeRx+4=
+
 prr@~1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/prr/-/prr-1.0.1.tgz#d3fc114ba06995a45ec6893f484ceb1d78f5f476"
@@ -5243,6 +5326,20 @@ punycode@^2.1.0:
   resolved "https://registry.yarnpkg.com/punycode/-/punycode-2.1.1.tgz#b58b010ac40c22c5657616c8d2c2c02c7bf479ec"
   integrity sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==
 
+puppeteer@^1.15.0:
+  version "1.15.0"
+  resolved "https://registry.yarnpkg.com/puppeteer/-/puppeteer-1.15.0.tgz#1680fac13e51f609143149a5b7fa99eec392b34f"
+  integrity sha512-D2y5kwA9SsYkNUmcBzu9WZ4V1SGHiQTmgvDZSx6sRYFsgV25IebL4V6FaHjF6MbwLK9C6f3G3pmck9qmwM8H3w==
+  dependencies:
+    debug "^4.1.0"
+    extract-zip "^1.6.6"
+    https-proxy-agent "^2.2.1"
+    mime "^2.0.3"
+    progress "^2.0.1"
+    proxy-from-env "^1.0.0"
+    rimraf "^2.6.1"
+    ws "^6.1.0"
+
 qs@4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/qs/-/qs-4.0.0.tgz#c31d9b74ec27df75e543a86c78728ed8d4623607"
@@ -7100,6 +7197,13 @@ ws@^4.0.0:
     async-limiter "~1.0.0"
     safe-buffer "~5.1.0"
 
+ws@^6.1.0:
+  version "6.2.1"
+  resolved "https://registry.yarnpkg.com/ws/-/ws-6.2.1.tgz#442fdf0a47ed64f59b6a5d8ff130f4748ed524fb"
+  integrity sha512-GIyAXC2cB7LjvpgMt9EKS2ldqr0MTrORaleiOno6TweZ6r3TKtoFQWay/2PceJ3RuBasOHzXNn5Lrw1X0bEjqA==
+  dependencies:
+    async-limiter "~1.0.0"
+
 xdg-basedir@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/xdg-basedir/-/xdg-basedir-2.0.0.tgz#edbc903cc385fc04523d966a335504b5504d1bd2"
@@ -7222,6 +7326,13 @@ yargs@~3.10.0:
     decamelize "^1.0.0"
     window-size "0.1.0"
 
+yauzl@2.4.1:
+  version "2.4.1"
+  resolved "https://registry.yarnpkg.com/yauzl/-/yauzl-2.4.1.tgz#9528f442dab1b2284e58b4379bb194e22e0c4005"
+  integrity sha1-lSj0QtqxsihOWLQ3m7GU4i4MQAU=
+  dependencies:
+    fd-slicer "~1.0.1"
+
 zmodem.js@^0.1.5:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/zmodem.js/-/zmodem.js-0.1.7.tgz#247affb76d2b1e3042b3fc8b4a087b9d5db8d1ed"

From d694eae6b5e4dd717aaa2fba0da998d4f0e41fbd Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 10:32:53 -0700
Subject: [PATCH 07/12] Add some buffer tests

---
 src/public/Terminal.api.ts | 68 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/src/public/Terminal.api.ts b/src/public/Terminal.api.ts
index 380cc89c3a..daa160d3e1 100644
--- a/src/public/Terminal.api.ts
+++ b/src/public/Terminal.api.ts
@@ -231,6 +231,74 @@ describe('API Integration Tests', () => {
       assert.deepEqual(await page.evaluate(`window.calls`), ['foo']);
     });
   });
+
+  describe('buffer', () => {
+    it('cursorX, cursorY', async function(): Promise<any> {
+      this.timeout(10000);
+      await openTerminal({ rows: 5, cols: 5 });
+      assert.equal(await page.evaluate(`window.term.buffer.cursorX`), 0);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorY`), 0);
+      await page.evaluate(`window.term.write('foo')`);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorX`), 3);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorY`), 0);
+      await page.evaluate(`window.term.write('\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorX`), 3);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorY`), 1);
+      await page.evaluate(`window.term.write('\\r')`);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorX`), 0);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorY`), 1);
+      await page.evaluate(`window.term.write('abcde')`);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorX`), 5);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorY`), 1);
+      await page.evaluate(`window.term.write('\\n\\r\\n\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorX`), 0);
+      assert.equal(await page.evaluate(`window.term.buffer.cursorY`), 4);
+    });
+
+    it('viewportY', async function(): Promise<any> {
+      this.timeout(10000);
+      await openTerminal({ rows: 5 });
+      assert.equal(await page.evaluate(`window.term.buffer.viewportY`), 0);
+      await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.viewportY`), 0);
+      await page.evaluate(`window.term.write('\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.viewportY`), 1);
+      await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.viewportY`), 5);
+      await page.evaluate(`window.term.scrollLines(-1)`);
+      assert.equal(await page.evaluate(`window.term.buffer.viewportY`), 4);
+      await page.evaluate(`window.term.scrollToTop()`);
+      assert.equal(await page.evaluate(`window.term.buffer.viewportY`), 0);
+    });
+
+    it('baseY', async function(): Promise<any> {
+      this.timeout(10000);
+      await openTerminal({ rows: 5 });
+      assert.equal(await page.evaluate(`window.term.buffer.baseY`), 0);
+      await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.baseY`), 0);
+      await page.evaluate(`window.term.write('\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.baseY`), 1);
+      await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.baseY`), 5);
+      await page.evaluate(`window.term.scrollLines(-1)`);
+      assert.equal(await page.evaluate(`window.term.buffer.baseY`), 5);
+      await page.evaluate(`window.term.scrollToTop()`);
+      assert.equal(await page.evaluate(`window.term.buffer.baseY`), 5);
+    });
+
+    it('length', async function(): Promise<any> {
+      this.timeout(10000);
+      await openTerminal({ rows: 5 });
+      assert.equal(await page.evaluate(`window.term.buffer.length`), 5);
+      await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.length`), 5);
+      await page.evaluate(`window.term.write('\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.length`), 6);
+      await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
+      assert.equal(await page.evaluate(`window.term.buffer.length`), 10);
+    });
+  });
 });
 
 async function openTerminal(options: ITerminalOptions = {}): Promise<void> {

From 46995fdbc1d5b308a04d746df5417d9e5b4e8c1d Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 10:46:00 -0700
Subject: [PATCH 08/12] Add tests for buffer.getLine

---
 src/public/Terminal.api.ts | 45 ++++++++++++++++++++++++++++++++++++++
 typings/xterm.d.ts         |  7 +++++-
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/src/public/Terminal.api.ts b/src/public/Terminal.api.ts
index daa160d3e1..6d777ee171 100644
--- a/src/public/Terminal.api.ts
+++ b/src/public/Terminal.api.ts
@@ -298,6 +298,51 @@ describe('API Integration Tests', () => {
       await page.evaluate(`window.term.write('\\n\\n\\n\\n')`);
       assert.equal(await page.evaluate(`window.term.buffer.length`), 10);
     });
+
+    describe('getLine', () => {
+      it('isWrapped', async function(): Promise<any> {
+        this.timeout(10000);
+        await openTerminal({ cols: 5 });
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).isWrapped`), false);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(1).isWrapped`), false);
+        await page.evaluate(`window.term.write('abcde')`);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).isWrapped`), false);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(1).isWrapped`), false);
+        await page.evaluate(`window.term.write('f')`);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).isWrapped`), false);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(1).isWrapped`), true);
+      });
+
+      it('translateToString', async function(): Promise<any> {
+        this.timeout(10000);
+        await openTerminal({ cols: 5 });
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString()`), '     ');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), '');
+        await page.evaluate(`window.term.write('foo')`);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString()`), 'foo  ');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), 'foo');
+        await page.evaluate(`window.term.write('bar')`);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString()`), 'fooba');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), 'fooba');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(1).translateToString(true)`), 'r');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(false, 1)`), 'ooba');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(false, 1, 3)`), 'oo');
+      });
+
+      it('getCell', async function(): Promise<any> {
+        this.timeout(10000);
+        await openTerminal();
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(0).char`), '');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(0).width`), 1);
+        await page.evaluate(`window.term.write('a文')`);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(0).char`), 'a');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(0).width`), 1);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(1).char`), '文');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(1).width`), 2);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(2).char`), '');
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(2).width`), 0);
+      });
+    });
   });
 });
 
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 49bb6c3197..00e7b215e2 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -916,7 +916,12 @@ declare module 'xterm' {
     getCell(x: number): IBufferCell;
 
     /**
-     * Gets the line
+     * Gets the line as a string. Note that this is gets only the string for the line, not taking
+     * isWrapped into account.
+     *
+     * @param trimRight Whether to trim any whitespace at the right of the line.
+     * @param startColumn The column to start from (inclusive).
+     * @param endColumn The column to end at (exclusive).
      */
     translateToString(trimRight?: boolean, startColumn?: number, endColumn?: number): string;
   }

From cd3f2609d6ecae53c1de4cb5835b759394b856b6 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 12:12:53 -0700
Subject: [PATCH 09/12] Make tests use buffer API over _core

---
 src/public/Terminal.api.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/public/Terminal.api.ts b/src/public/Terminal.api.ts
index 6d777ee171..935e160300 100644
--- a/src/public/Terminal.api.ts
+++ b/src/public/Terminal.api.ts
@@ -48,7 +48,7 @@ describe('API Integration Tests', () => {
       window.term.write('foo');
       window.term.write('bar');
     `);
-    assert.equal(await page.evaluate(`window.term._core.buffer.translateBufferLineToString(0, true)`), 'foobar');
+    assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), 'foobar');
   });
 
   it('writeln', async function(): Promise<any> {
@@ -58,8 +58,8 @@ describe('API Integration Tests', () => {
       window.term.writeln('foo');
       window.term.writeln('bar');
     `);
-    assert.equal(await page.evaluate(`window.term._core.buffer.translateBufferLineToString(0, true)`), 'foo');
-    assert.equal(await page.evaluate(`window.term._core.buffer.translateBufferLineToString(1, true)`), 'bar');
+    assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), 'foo');
+    assert.equal(await page.evaluate(`window.term.buffer.getLine(1).translateToString(true)`), 'bar');
   });
 
   it('clear', async function(): Promise<any> {
@@ -72,10 +72,10 @@ describe('API Integration Tests', () => {
       }
     `);
     await page.evaluate(`window.term.clear()`);
-    assert.equal(await page.evaluate(`window.term._core.buffer.lines.length`), '5');
-    assert.equal(await page.evaluate(`window.term._core.buffer.translateBufferLineToString(0, true)`), 'test9');
+    assert.equal(await page.evaluate(`window.term.buffer.length`), '5');
+    assert.equal(await page.evaluate(`window.term.buffer.getLine(0).translateToString(true)`), 'test9');
     for (let i = 1; i < 5; i++) {
-      assert.equal(await page.evaluate(`window.term._core.buffer.translateBufferLineToString(${i}, true)`), '');
+      assert.equal(await page.evaluate(`window.term.buffer.getLine(${i}).translateToString(true)`), '');
     }
   });
 

From f41e00ed97f6798dbc957bdcb9c3c049c3b56166 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 20:46:55 -0700
Subject: [PATCH 10/12] Return undefined if cell or line doesn't exist

---
 src/public/Terminal.ts | 9 +++++++--
 typings/xterm.d.ts     | 6 +++---
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/public/Terminal.ts b/src/public/Terminal.ts
index ee623ca334..dd07c73580 100644
--- a/src/public/Terminal.ts
+++ b/src/public/Terminal.ts
@@ -180,14 +180,19 @@ class BufferApiView implements IBufferApi {
   public get viewportY(): number { return this._buffer.ydisp; }
   public get baseY(): number { return this._buffer.ybase; }
   public get length(): number { return this._buffer.lines.length; }
-  public getLine(y: number): IBufferLineApi { return new BufferLineApiView(this._buffer.lines.get(y)); }
+  public getLine(y: number): IBufferLineApi | undefined { return new BufferLineApiView(this._buffer.lines.get(y)); }
 }
 
 class BufferLineApiView implements IBufferLineApi {
   constructor(private _line: IBufferLine) {}
 
   public get isWrapped(): boolean { return this._line.isWrapped; }
-  public getCell(x: number): IBufferCellApi { return new BufferCellApiView(this._line, x); }
+  public getCell(x: number): IBufferCellApi | undefined {
+    if (x < 0 && x >= this._line.length) {
+      return undefined;
+    }
+    return new BufferCellApiView(this._line, x);
+  }
   public translateToString(trimRight?: boolean, startColumn?: number, endColumn?: number): string {
     return this._line.translateToString(trimRight, startColumn, endColumn);
   }
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index 00e7b215e2..e9643b6392 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -895,11 +895,11 @@ declare module 'xterm' {
     readonly length: number;
 
     /**
-     * Gets a line from the buffer.
+     * Gets a line from the buffer, or undefined if the line index does not exist.
      *
      * @param y The line index to get.
      */
-    getLine(y: number): IBufferLine;
+    getLine(y: number): IBufferLine | undefined;
   }
 
   interface IBufferLine {
@@ -909,7 +909,7 @@ declare module 'xterm' {
     readonly isWrapped: boolean;
 
     /**
-     * Gets a cell from the line.
+     * Gets a cell from the line, or undefined if the line index does not exist.
      *
      * @param x The character index to get.
      */

From 49574be510ce7ac5a9b02e1dc96cbff80f710504 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 20:49:48 -0700
Subject: [PATCH 11/12] Add warnings to getCell and getLine

---
 typings/xterm.d.ts | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index e9643b6392..0714f55f0a 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -356,9 +356,9 @@ declare module 'xterm' {
     readonly cols: number;
 
     /**
-     * (EXPERIMENTAL) The terminal's current buffer, note that this might be
-     * either the normal buffer or the alt buffer depending on what's running in
-     * the terminal.
+     * (EXPERIMENTAL) The terminal's current buffer, this might be either the
+     * normal buffer or the alt buffer depending on what's running in the
+     * terminal.
      */
     readonly buffer: IBuffer;
 
@@ -897,6 +897,9 @@ declare module 'xterm' {
     /**
      * Gets a line from the buffer, or undefined if the line index does not exist.
      *
+     * Note that the result of this function should be used immediately after calling as when the
+     * terminal updates it could lead to unexpected behavior.
+     *
      * @param y The line index to get.
      */
     getLine(y: number): IBufferLine | undefined;
@@ -911,6 +914,9 @@ declare module 'xterm' {
     /**
      * Gets a cell from the line, or undefined if the line index does not exist.
      *
+     * Note that the result of this function should be used immediately after calling as when the
+     * terminal updates it could lead to unexpected behavior.
+     *
      * @param x The character index to get.
      */
     getCell(x: number): IBufferCell;

From 70ba349a858d2fcb810e60db53a5ba142b8f365c Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Sat, 11 May 2019 20:58:51 -0700
Subject: [PATCH 12/12] Fix invalid index check, add api tests

---
 src/public/Terminal.api.ts | 11 ++++++++++-
 src/public/Terminal.ts     | 10 ++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/public/Terminal.api.ts b/src/public/Terminal.api.ts
index 935e160300..031e03d54a 100644
--- a/src/public/Terminal.api.ts
+++ b/src/public/Terminal.api.ts
@@ -300,6 +300,13 @@ describe('API Integration Tests', () => {
     });
 
     describe('getLine', () => {
+      it('invalid index', async function(): Promise<any> {
+        this.timeout(10000);
+        await openTerminal({ rows: 5 });
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(-1)`), undefined);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(5)`), undefined);
+      });
+
       it('isWrapped', async function(): Promise<any> {
         this.timeout(10000);
         await openTerminal({ cols: 5 });
@@ -331,7 +338,9 @@ describe('API Integration Tests', () => {
 
       it('getCell', async function(): Promise<any> {
         this.timeout(10000);
-        await openTerminal();
+        await openTerminal({ cols: 5 });
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(-1)`), undefined);
+        assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(5)`), undefined);
         assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(0).char`), '');
         assert.equal(await page.evaluate(`window.term.buffer.getLine(0).getCell(0).width`), 1);
         await page.evaluate(`window.term.write('a文')`);
diff --git a/src/public/Terminal.ts b/src/public/Terminal.ts
index dd07c73580..0c6a77457e 100644
--- a/src/public/Terminal.ts
+++ b/src/public/Terminal.ts
@@ -180,7 +180,13 @@ class BufferApiView implements IBufferApi {
   public get viewportY(): number { return this._buffer.ydisp; }
   public get baseY(): number { return this._buffer.ybase; }
   public get length(): number { return this._buffer.lines.length; }
-  public getLine(y: number): IBufferLineApi | undefined { return new BufferLineApiView(this._buffer.lines.get(y)); }
+  public getLine(y: number): IBufferLineApi | undefined {
+    const line = this._buffer.lines.get(y);
+    if (!line) {
+      return undefined;
+    }
+    return new BufferLineApiView(line);
+  }
 }
 
 class BufferLineApiView implements IBufferLineApi {
@@ -188,7 +194,7 @@ class BufferLineApiView implements IBufferLineApi {
 
   public get isWrapped(): boolean { return this._line.isWrapped; }
   public getCell(x: number): IBufferCellApi | undefined {
-    if (x < 0 && x >= this._line.length) {
+    if (x < 0 || x >= this._line.length) {
       return undefined;
     }
     return new BufferCellApiView(this._line, x);