Expand unit test infrastructure.

- This expansion mostly mocks out a few core types that are needed to do anythign with the VSCode APIs and also changes the programming model to manipulate the VSCode workspace, extensions and output channels.
- Also cleaned up a few missed changes in some src files.

.vscode/tasks.json

@@ -6,8 +6,8 @@
         {
             "label": "client-npm-compile",
             "dependsOn": [
-                "client-npm-compile:shell",
-                "client-npm-compile:package"
+                "client-npm-compile:package",
+                "client-npm-compile:shell"
             ],
             "group": {
                 "kind": "build",

client/tsconfig.json

@@ -2,7 +2,7 @@
 	"compilerOptions": {
 		"baseUrl": ".",
 		"module": "commonjs",
-		"target": "es5",
+		"target": "es6",
 		"outDir": "out",
 		"lib": [
 			"es6", "es2017.object"

client/unittest/Mocks/TestEventEmitter.ts

@@ -0,0 +1,48 @@
+/* --------------------------------------------------------------------------------------------
+* Copyright (c) Microsoft Corporation. All rights reserved.
+* Licensed under the MIT License. See License.txt in the project root for license information.
+* ------------------------------------------------------------------------------------------ */
+
+import * as vscode from 'microsoft.aspnetcore.razor.vscode/dist/vscodeAdapter';
+
+export class TestEventEmitter<T> implements vscode.EventEmitter<T> {
+
+    /**
+     * The event listeners can subscribe to.
+     */
+    public readonly event: vscode.Event<T>;
+
+    private readonly listeners: Array<(e: T) => any> = [];
+
+    constructor() {
+        this.event = (listener: (e: T) => any, thisArgs?: any, disposables?: vscode.Disposable[]) => {
+            this.listeners.push(listener);
+            return {
+                dispose: Function,
+            };
+        };
+    }
+
+    /**
+     * Notify all subscribers of the [event](EventEmitter#event). Failure
+     * of one or more listener will not fail this function call.
+     *
+     * @param data The event object.
+     */
+    public fire(data?: T) {
+        for (const listener of this.listeners) {
+            if (data) {
+                listener(data);
+            } else {
+                throw new Error('Event emitters do not implement firing events without data.');
+            }
+        }
+    }
+
+    /**
+     * Dispose this object and free resources.
+     */
+    public dispose() {
+        // @ts-ignore
+    }
+}

client/unittest/Mocks/TestEventEmitterFactory.ts

@@ -0,0 +1,13 @@
+/* --------------------------------------------------------------------------------------------
+* Copyright (c) Microsoft Corporation. All rights reserved.
+* Licensed under the MIT License. See License.txt in the project root for license information.
+* ------------------------------------------------------------------------------------------ */
+
+import { IEventEmitterFactory } from 'microsoft.aspnetcore.razor.vscode/dist/IEventEmitterFactory';
+import { TestEventEmitter } from './TestEventEmitter';
+
+export class TestEventEmitterFactory implements IEventEmitterFactory {
+    public create<T>() {
+        return new TestEventEmitter<T>();
+    }
+}

client/unittest/Mocks/TestTextDocument.ts

@@ -0,0 +1,80 @@
+/* --------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ * ------------------------------------------------------------------------------------------ */
+
+import { RazorLanguage } from 'microsoft.aspnetcore.razor.vscode/dist/RazorLanguage';
+import * as vscode from 'microsoft.aspnetcore.razor.vscode/dist/vscodeAdapter';
+import { EndOfLine } from 'microsoft.aspnetcore.razor.vscode/dist/vscodeAdapter';
+import * as os from 'os';
+
+export class TestTextDocument implements vscode.TextDocument {
+
+    public readonly isUntitled = false;
+
+    public readonly version = 0;
+
+    public readonly isDirty: boolean = false;
+
+    public readonly lineCount: number;
+
+    constructor(
+        private readonly content: string,
+        public readonly uri: vscode.Uri,
+        public readonly languageId: string = RazorLanguage.id) {
+
+        this.lineCount = content.split(os.EOL).length;
+    }
+
+    public get fileName(): string {
+        throw new Error('Not implemented');
+    }
+
+    public get isClosed(): boolean {
+        throw new Error('Not implemented');
+    }
+
+    public get eol(): EndOfLine {
+        if (os.EOL.startsWith('\r')) {
+            return EndOfLine.CRLF;
+        }
+
+        return EndOfLine.LF;
+    }
+
+    public save(): vscode.Thenable<boolean> {
+        return new Promise<boolean>((resolve) => resolve(true));
+    }
+
+    public lineAt(line: any): vscode.TextLine {
+        throw new Error('Not implemented');
+    }
+
+    public offsetAt(position: vscode.Position): number {
+        throw new Error('Not implemented');
+    }
+
+    public positionAt(offset: number): vscode.Position {
+        throw new Error('Not implemented');
+    }
+
+    public getText(range?: vscode.Range): string {
+        if (range) {
+            throw new Error('getText is not implemented with range');
+        }
+
+        return this.content;
+    }
+
+    public getWordRangeAtPosition(position: vscode.Position, regex?: RegExp): vscode.Range | undefined {
+        throw new Error('Not implemented');
+    }
+
+    public validateRange(range: vscode.Range): vscode.Range {
+        throw new Error('Not implemented');
+    }
+
+    public validatePosition(position: vscode.Position): vscode.Position {
+        throw new Error('Not implemented');
+    }
+}

client/unittest/Mocks/TestUri.ts

@@ -0,0 +1,35 @@
+/* --------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ * ------------------------------------------------------------------------------------------ */
+
+import * as vscode from 'microsoft.aspnetcore.razor.vscode/dist/vscodeAdapter';
+
+export class TestUri implements vscode.Uri {
+    constructor(
+        public readonly path: string,
+        public readonly query = path,
+        public readonly scheme = 'unknown',
+        public readonly authority = 'unknown',
+        public readonly fragment = 'unknown',
+        public readonly fsPath = path) {
+    }
+
+    public with(change: {
+        scheme?: string;
+        authority?: string;
+        path?: string;
+        query?: string;
+        fragment?: string;
+    }): vscode.Uri {
+        throw new Error('Not Implemented.');
+    }
+
+    public toString(skipEncoding?: boolean): string {
+        throw new Error('Not Implemented.');
+    }
+
+    public toJSON(): any {
+        throw new Error('Not Implemented.');
+    }
+}

client/unittest/Mocks/TestVSCodeApi.ts

@@ -0,0 +1,136 @@
+/* --------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ * ------------------------------------------------------------------------------------------ */
+
+import { RazorLogger } from 'microsoft.aspnetcore.razor.vscode/dist/RazorLogger';
+import * as vscode from 'microsoft.aspnetcore.razor.vscode/dist/vscodeAdapter';
+import * as os from 'os';
+import { TestUri } from './TestUri';
+
+export interface TestVSCodeApi extends vscode.api {
+    getOutputChannelSink(): { [logIdentifier: string]: string[] };
+    getRazorOutputChannel(): string[];
+    setWorkspaceDocuments(...workspaceDocuments: vscode.TextDocument[]): void;
+    setExtensions(...extensions: Array<vscode.Extension<any>>): void;
+}
+
+export function createTestVSCodeApi(): TestVSCodeApi {
+    const workspaceDocuments: vscode.TextDocument[] = [];
+    const extensions: Array<vscode.Extension<any>> = [];
+    const outputChannelSink: { [logIdentifier: string]: string[] } = {};
+    return {
+        // Non-VSCode APIs, for tests only
+
+        getOutputChannelSink: () => outputChannelSink,
+        getRazorOutputChannel: () => {
+            let razorOutputChannel = outputChannelSink[RazorLogger.logName];
+            if (!razorOutputChannel) {
+                razorOutputChannel = [];
+                outputChannelSink[RazorLogger.logName] = razorOutputChannel;
+            }
+
+            return razorOutputChannel;
+        },
+        setWorkspaceDocuments: (...documents) => {
+            workspaceDocuments.length = 0;
+            workspaceDocuments.push(...documents);
+        },
+        setExtensions: (...exts: Array<vscode.Extension<any>>) => {
+            extensions.length = 0;
+            extensions.push(...exts);
+        },
+
+        // VSCode APIs
+
+        commands: {
+            executeCommand: <T>(command: string, ...rest: any[]) => {
+                throw new Error('Not Implemented');
+            },
+            registerCommand: (command: string, callback: (...args: any[]) => any, thisArg?: any) => {
+                throw new Error('Not Implemented');
+            },
+        },
+        languages: {
+            match: (selector: vscode.DocumentSelector, document: vscode.TextDocument) => {
+                throw new Error('Not Implemented');
+            },
+        },
+        window: {
+            activeTextEditor: undefined,
+            showInformationMessage: <T extends vscode.MessageItem>(message: string, ...items: T[]) => {
+                throw new Error('Not Implemented');
+            },
+            showWarningMessage: <T extends vscode.MessageItem>(message: string, ...items: T[]) => {
+                throw new Error('Not Implemented');
+            },
+            showErrorMessage: (message: string, ...items: string[]) => {
+                throw new Error('Not Implemented');
+            },
+            createOutputChannel: (name: string) => {
+                if (!outputChannelSink[name]) {
+                    outputChannelSink[name] = [];
+                }
+                const outputChannel: vscode.OutputChannel = {
+                    name,
+                    append: (message) => outputChannelSink[name].push(message),
+                    appendLine: (message) => outputChannelSink[name].push(`${message}${os.EOL}`),
+                    clear: () => outputChannelSink[name].length = 0,
+                    dispose: Function,
+                    hide: Function,
+                    show: () => {
+                        // @ts-ignore
+                    },
+                };
+
+                return outputChannel;
+            },
+            registerWebviewPanelSerializer: (viewType: string, serializer: vscode.WebviewPanelSerializer) => {
+                throw new Error('Not implemented');
+            },
+        },
+        workspace: {
+            openTextDocument: (uri: vscode.Uri) => {
+                return new Promise((resolve) => {
+                    for (const document of workspaceDocuments) {
+                        if (document.uri === uri) {
+                            resolve(document);
+                        }
+                    }
+                    resolve(undefined);
+                });
+            },
+            getConfiguration: (section?: string, resource?: vscode.Uri) => {
+                throw new Error('Not Implemented');
+            },
+            asRelativePath: (pathOrUri: string | vscode.Uri, includeWorkspaceFolder?: boolean) => {
+                throw new Error('Not Implemented');
+            },
+            createFileSystemWatcher: (globPattern: vscode.GlobPattern, ignoreCreateEvents?: boolean, ignoreChangeEvents?: boolean, ignoreDeleteEvents?: boolean) => {
+                throw new Error('Not Implemented');
+            },
+            onDidChangeConfiguration: (listener: (e: vscode.ConfigurationChangeEvent) => any, thisArgs?: any, disposables?: vscode.Disposable[]): vscode.Disposable => {
+                throw new Error('Not Implemented');
+            },
+        },
+        extensions: {
+            getExtension: (id) => {
+                for (const extension of extensions) {
+                    if (extension.id === id) {
+                        return extension;
+                    }
+                }
+            },
+            all: extensions,
+        },
+        Uri: {
+            parse: (path) => new TestUri(path),
+        },
+        Disposable: {
+            from: (...disposableLikes: Array<{ dispose: () => any }>) => {
+                throw new Error('Not Implemented');
+            },
+        },
+        version: '',
+    };
+}

client/unittest/RazorLogger.test.ts

@@ -6,7 +6,8 @@
 import * as assert from 'assert';
 import { RazorLogger } from 'microsoft.aspnetcore.razor.vscode/dist/RazorLogger';
 import { Trace } from 'microsoft.aspnetcore.razor.vscode/dist/Trace';
-import { createLogSink as useOutputChannelSink, getFakeVsCodeApi } from './vscodeMock';
+import { TestEventEmitterFactory } from './Mocks/TestEventEmitterFactory';
+import { createTestVSCodeApi } from './Mocks/TestVSCodeApi';
 
 describe('RazorLogger', () => {
     function getAndAssertLog(sink: { [logName: string]: string[] }) {
@@ -19,11 +20,11 @@ describe('Razor Logger', () => {
 
     it('Always logs information header', () => {
         // Arrange
-        const vscodeApi = getFakeVsCodeApi();
-        const sink = useOutputChannelSink(vscodeApi);
+        const api = createTestVSCodeApi();
+        const sink = api.getOutputChannelSink();
 
         // Act
-        const logger = new RazorLogger(vscodeApi, Trace.Off);
+        const logger = new RazorLogger(api, Trace.Off);
 
         // Assert
         const log = getAndAssertLog(sink);
@@ -33,9 +34,9 @@ describe('Razor Logger', () => {
 
     it('logAlways logs when trace is Off', () => {
         // Arrange
-        const vscodeApi = getFakeVsCodeApi();
-        const sink = useOutputChannelSink(vscodeApi);
-        const logger = new RazorLogger(vscodeApi, Trace.Off);
+        const api = createTestVSCodeApi();
+        const sink = api.getOutputChannelSink();
+        const logger = new RazorLogger(api, Trace.Off);
 
         // Act
         logger.logAlways('Test');
@@ -48,9 +49,9 @@ describe('Razor Logger', () => {
 
     it('logError logs when trace is Off', () => {
         // Arrange
-        const vscodeApi = getFakeVsCodeApi();
-        const sink = useOutputChannelSink(vscodeApi);
-        const logger = new RazorLogger(vscodeApi, Trace.Off);
+        const api = createTestVSCodeApi();
+        const sink = api.getOutputChannelSink();
+        const logger = new RazorLogger(api, Trace.Off);
 
         // Act
         logger.logError('Test Error');
@@ -63,9 +64,9 @@ describe('Razor Logger', () => {
 
     it('logMessage does not log when trace is Off', () => {
         // Arrange
-        const vscodeApi = getFakeVsCodeApi();
-        const sink = useOutputChannelSink(vscodeApi);
-        const logger = new RazorLogger(vscodeApi, Trace.Off);
+        const api = createTestVSCodeApi();
+        const sink = api.getOutputChannelSink();
+        const logger = new RazorLogger(api, Trace.Off);
 
         // Act
         logger.logMessage('Test message');
@@ -79,9 +80,9 @@ describe('Razor Logger', () => {
     for (const trace of [Trace.Messages, Trace.Verbose]) {
         it(`logMessage logs when trace is ${Trace[trace]}`, () => {
             // Arrange
-            const vscodeApi = getFakeVsCodeApi();
-            const sink = useOutputChannelSink(vscodeApi);
-            const logger = new RazorLogger(vscodeApi, trace);
+            const api = createTestVSCodeApi();
+            const sink = api.getOutputChannelSink();
+            const logger = new RazorLogger(api, trace);
 
             // Act
             logger.logMessage('Test message');
@@ -96,9 +97,9 @@ describe('Razor Logger', () => {
     for (const trace of [Trace.Off, Trace.Messages]) {
         it(`logVerbose does not log when trace is ${Trace[trace]}`, () => {
             // Arrange
-            const vscodeApi = getFakeVsCodeApi();
-            const sink = useOutputChannelSink(vscodeApi);
-            const logger = new RazorLogger(vscodeApi, trace);
+            const api = createTestVSCodeApi();
+            const sink = api.getOutputChannelSink();
+            const logger = new RazorLogger(api, trace);
 
             // Act
             logger.logVerbose('Test message');
@@ -112,9 +113,9 @@ describe('Razor Logger', () => {
 
     it('logVerbose logs when trace is Verbose', () => {
         // Arrange
-        const vscodeApi = getFakeVsCodeApi();
-        const sink = useOutputChannelSink(vscodeApi);
-        const logger = new RazorLogger(vscodeApi, Trace.Verbose);
+        const api = createTestVSCodeApi();
+        const sink = api.getOutputChannelSink();
+        const logger = new RazorLogger(api, Trace.Verbose);
 
         // Act
         logger.logVerbose('Test message');

client/unittest/vscodeMock.ts

@@ -1,87 +0,0 @@
-/* --------------------------------------------------------------------------------------------
- * Copyright (c) Microsoft Corporation. All rights reserved.
- * Licensed under the MIT License. See License.txt in the project root for license information.
- * ------------------------------------------------------------------------------------------ */
-
-import * as vscode from 'Microsoft.AspNetCore.Razor.VSCode/dist/vscodeAdapter';
-import * as os from 'os';
-
-export function createLogSink(api: vscode.api) {
-    const sink: { [logIdentifier: string]: string[] } = {};
-    api.window.createOutputChannel = (name) => {
-        if (!sink[name]) {
-            sink[name] = [];
-        }
-        const outputChannel: vscode.OutputChannel = {
-            name,
-            append: (message) => sink[name].push(message),
-            appendLine: (message) => sink[name].push(`${message}${os.EOL}`),
-            clear: () => sink[name].length = 0,
-            dispose: Function,
-            hide: Function,
-            show: () => {
-                // @ts-ignore
-             },
-        };
-
-        return outputChannel;
-    };
-
-    return sink;
-}
-
-export function getFakeVsCodeApi(): vscode.api {
-    return {
-        commands: {
-            executeCommand: <T>(command: string, ...rest: any[]) => {
-                throw new Error('Not Implemented');
-            },
-        },
-        languages: {
-            match: (selector: vscode.DocumentSelector, document: vscode.TextDocument) => {
-                throw new Error('Not Implemented');
-            },
-        },
-        window: {
-            activeTextEditor: undefined,
-            showInformationMessage: <T extends vscode.MessageItem>(message: string, ...items: T[]) => {
-                throw new Error('Not Implemented');
-            },
-            showWarningMessage: <T extends vscode.MessageItem>(message: string, ...items: T[]) => {
-                throw new Error('Not Implemented');
-            },
-            showErrorMessage: (message: string, ...items: string[]) => {
-                throw new Error('Not Implemented');
-            },
-            createOutputChannel: (name: string) => {
-                throw new Error('Not implemented');
-            },
-        },
-        workspace: {
-            getConfiguration: (section?: string, resource?: vscode.Uri) => {
-                throw new Error('Not Implemented');
-            },
-            asRelativePath: (pathOrUri: string | vscode.Uri, includeWorkspaceFolder?: boolean) => {
-                throw new Error('Not Implemented');
-            },
-            createFileSystemWatcher: (globPattern: vscode.GlobPattern, ignoreCreateEvents?: boolean, ignoreChangeEvents?: boolean, ignoreDeleteEvents?: boolean) => {
-                throw new Error('Not Implemented');
-            },
-            onDidChangeConfiguration: (listener: (e: vscode.ConfigurationChangeEvent) => any, thisArgs?: any, disposables?: vscode.Disposable[]): vscode.Disposable => {
-                throw new Error('Not Implemented');
-            },
-        },
-        extensions: {
-            getExtension: () => {
-                throw new Error('Not Implemented');
-            },
-            all: [],
-        },
-        Uri: {
-            parse: () => {
-                throw new Error('Not Implemented');
-            },
-        },
-        version: '',
-    };
-}

src/Microsoft.AspNetCore.Razor.LanguageServer/ProjectSystem/DefaultRazorProjectService.cs

@@ -378,6 +378,5 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.ProjectSystem
                 return textAndVersion;
             }
         }
-
     }
 }

src/Microsoft.AspNetCore.Razor.VSCode/src/RPC/AddProjectRequest.ts

@@ -4,6 +4,6 @@
  * ------------------------------------------------------------------------------------------ */
 
 export class AddProjectRequest {
-    constructor(public readonly filePath: string, public readonly configurationName?: string) {
+    constructor(public readonly filePath: string) {
     }
 }

src/Microsoft.AspNetCore.Razor.VSCode/src/vscodeAdapter.ts

@@ -4,6 +4,58 @@
  *--------------------------------------------------------------------------------------------*/
 /* tslint:disable */
 
+
+
+/**
+ * Represents a typed event.
+ *
+ * A function that represents an event to which you subscribe by calling it with
+ * a listener function as argument.
+ *
+ * @sample `item.onDidChange(function(event) { console.log("Event happened: " + event); });`
+ */
+export interface Event<T> {
+
+    /**
+     * A function that represents an event to which you subscribe by calling it with
+     * a listener function as argument.
+     *
+     * @param listener The listener function will be called when the event happens.
+     * @param thisArgs The `this`-argument which will be used when calling the event listener.
+     * @param disposables An array to which a [disposable](#Disposable) will be added.
+     * @return A disposable which unsubscribes the event listener.
+     */
+    (listener: (e: T) => any, thisArgs?: any, disposables?: Disposable[]): Disposable;
+}
+
+/**
+ * An event emitter can be used to create and manage an [event](#Event) for others
+ * to subscribe to. One emitter always owns one event.
+ *
+ * Use this class if you want to provide event from within your extension, for instance
+ * inside a [TextDocumentContentProvider](#TextDocumentContentProvider) or when providing
+ * API to other extensions.
+ */
+export declare class EventEmitter<T> {
+    /**
+     * The event listeners can subscribe to.
+     */
+    event: Event<T>;
+
+    /**
+     * Notify all subscribers of the [event](EventEmitter#event). Failure
+     * of one or more listener will not fail this function call.
+     *
+     * @param data The event object.
+     */
+    fire(data?: T): void;
+
+    /**
+     * Dispose this object and free resources.
+     */
+    dispose(): void;
+}
+
 export interface OutputChannel {
 
     /**
@@ -885,6 +937,197 @@ export interface ConfigurationChangeEvent {
     affectsConfiguration(section: string, resource?: Uri): boolean;
 }
 
+export interface WebviewPanelSerializer {
+    /**
+     * Restore a webview panel from its seriailzed `state`.
+     *
+     * Called when a serialized webview first becomes visible.
+     *
+     * @param webviewPanel Webview panel to restore. The serializer should take ownership of this panel. The
+     * serializer must restore the webview's `.html` and hook up all webview events.
+     * @param state Persisted state from the webview content.
+     *
+     * @return Thanble indicating that the webview has been fully restored.
+     */
+    deserializeWebviewPanel(webviewPanel: WebviewPanel, state: any): Thenable<void>;
+}
+
+/**
+ * Content settings for a webview panel.
+ */
+export interface WebviewPanelOptions {
+    /**
+     * Controls if the find widget is enabled in the panel.
+     *
+     * Defaults to false.
+     */
+    readonly enableFindWidget?: boolean;
+
+    /**
+     * Controls if the webview panel's content (iframe) is kept around even when the panel
+     * is no longer visible.
+     *
+     * Normally the webview panel's html context is created when the panel becomes visible
+     * and destroyed when it is is hidden. Extensions that have complex state
+     * or UI can set the `retainContextWhenHidden` to make VS Code keep the webview
+     * context around, even when the webview moves to a background tab. When a webview using
+     * `retainContextWhenHidden` becomes hidden, its scripts and other dynamic content are suspended.
+     * When the panel becomes visible again, the context is automatically restored
+     * in the exact same state it was in originally. You cannot send messages to a
+     * hidden webview, even with `retainContextWhenHidden` enabled.
+     *
+     * `retainContextWhenHidden` has a high memory overhead and should only be used if
+     * your panel's context cannot be quickly saved and restored.
+     */
+    readonly retainContextWhenHidden?: boolean;
+}
+
+/**
+ * A panel that contains a webview.
+ */
+export interface WebviewPanel {
+    /**
+     * Identifies the type of the webview panel, such as `'markdown.preview'`.
+     */
+    readonly viewType: string;
+
+    /**
+     * Title of the panel shown in UI.
+     */
+    title: string;
+
+    /**
+     * Webview belonging to the panel.
+     */
+    readonly webview: Webview;
+
+    /**
+     * Content settings for the webview panel.
+     */
+    readonly options: WebviewPanelOptions;
+
+    /**
+     * Editor position of the panel. This property is only set if the webview is in
+     * one of the editor view columns.
+     *
+     * @deprecated
+     */
+    readonly viewColumn?: ViewColumn;
+
+    /**
+     * Whether the panel is active (focused by the user).
+     */
+    readonly active: boolean;
+
+    /**
+     * Whether the panel is visible.
+     */
+    readonly visible: boolean;
+
+    /**
+     * Fired when the panel's view state changes.
+     */
+    readonly onDidChangeViewState: Event<WebviewPanelOnDidChangeViewStateEvent>;
+
+    /**
+     * Fired when the panel is disposed.
+     *
+     * This may be because the user closed the panel or because `.dispose()` was
+     * called on it.
+     *
+     * Trying to use the panel after it has been disposed throws an exception.
+     */
+    readonly onDidDispose: Event<void>;
+
+    /**
+     * Show the webview panel in a given column.
+     *
+     * A webview panel may only show in a single column at a time. If it is already showing, this
+     * method moves it to a new column.
+     *
+     * @param viewColumn View column to show the panel in. Shows in the current `viewColumn` if undefined.
+     * @param preserveFocus When `true`, the webview will not take focus.
+     */
+    reveal(viewColumn?: ViewColumn, preserveFocus?: boolean): void;
+
+    /**
+     * Dispose of the webview panel.
+     *
+     * This closes the panel if it showing and disposes of the resources owned by the webview.
+     * Webview panels are also disposed when the user closes the webview panel. Both cases
+     * fire the `onDispose` event.
+     */
+    dispose(): any;
+}
+
+/**
+ * Event fired when a webview panel's view state changes.
+ */
+export interface WebviewPanelOnDidChangeViewStateEvent {
+    /**
+     * Webview panel whose view state changed.
+     */
+    readonly webviewPanel: WebviewPanel;
+}
+
+/**
+ * A webview displays html content, like an iframe.
+ */
+export interface Webview {
+    /**
+     * Content settings for the webview.
+     */
+    options: WebviewOptions;
+
+    /**
+     * Contents of the webview.
+     *
+     * Should be a complete html document.
+     */
+    html: string;
+
+    /**
+     * Fired when the webview content posts a message.
+     */
+    readonly onDidReceiveMessage: Event<any>;
+
+    /**
+     * Post a message to the webview content.
+     *
+     * Messages are only delivered if the webview is visible.
+     *
+     * @param message Body of the message.
+     */
+    postMessage(message: any): Thenable<boolean>;
+}
+
+/**
+ * Content settings for a webview.
+ */
+export interface WebviewOptions {
+    /**
+     * Controls whether scripts are enabled in the webview content or not.
+     *
+     * Defaults to false (scripts-disabled).
+     */
+    readonly enableScripts?: boolean;
+
+    /**
+     * Controls whether command uris are enabled in webview content or not.
+     *
+     * Defaults to false.
+     */
+    readonly enableCommandUris?: boolean;
+
+    /**
+     * Root paths from which the webview can load local (filesystem) resources using the `vscode-resource:` scheme.
+     *
+     * Default to the root folders of the current workspace plus the extension's install directory.
+     *
+     * Pass in an empty array to disallow access to any local resources.
+     */
+    readonly localResourceRoots?: ReadonlyArray<Uri>;
+}
 
 /**
  * Thenable is a common denominator between ES6 promises, Q, jquery.Deferred, WinJS.Promise,
@@ -892,7 +1135,7 @@ export interface ConfigurationChangeEvent {
  * enables reusing existing code without migrating to a specific promise implementation. Still,
  * we recommend the use of native promises which are available in this editor.
  */
-interface Thenable<T> {
+export interface Thenable<T> {
     /**
 	* Attaches callbacks for the resolution and/or rejection of the Promise.
 	* @param onfulfilled The callback to execute when the Promise is resolved.
@@ -911,6 +1154,7 @@ export interface Extension<T>{
 export interface api {
     commands: {
         executeCommand: <T>(command: string, ...rest: any[]) => Thenable<T | undefined>;
+        registerCommand(command: string, callback: (...args: any[]) => any, thisArg?: any): Disposable;
     };
     languages: {
         match: (selector: DocumentSelector, document: TextDocument) => number;
@@ -921,8 +1165,10 @@ export interface api {
         showWarningMessage: <T extends MessageItem>(message: string, ...items: T[]) => Thenable<T | undefined>;
         showErrorMessage(message: string, ...items: string[]): Thenable<string | undefined>;
         createOutputChannel(name: string): OutputChannel;
+        registerWebviewPanelSerializer(viewType: string, serializer: WebviewPanelSerializer): Disposable;
     };
     workspace: {
+        openTextDocument: (uri: Uri) => Thenable<TextDocument>;
         getConfiguration: (section?: string, resource?: Uri) => WorkspaceConfiguration;
         asRelativePath: (pathOrUri: string | Uri, includeWorkspaceFolder?: boolean) => string;
         createFileSystemWatcher(globPattern: GlobPattern, ignoreCreateEvents?: boolean, ignoreChangeEvents?: boolean, ignoreDeleteEvents?: boolean): FileSystemWatcher;
@@ -935,6 +1181,9 @@ export interface api {
     Uri: {
         parse(value: string): Uri;
     };
+    Disposable: {
+        from(...disposableLikes: { dispose: () => any }[]): Disposable;
+    };
 
     version: string;
 }