Add 'omnisharp.autoStart' option that allows users to control whether OmniSharp is started automatically or not

package.json

@@ -99,6 +99,11 @@
             "verbose"
           ],
           "description": "Specifies the level of logging output from the OmniSharp server."
+        },
+        "omnisharp.autoStart": {
+          "type": "boolean",
+          "default": true,
+          "description": "Specifies whether the OmniSharp server will be automatically started or not. If false, OmniSharp can be started with the 'Restart OmniSharp' command"
         }
       }
     },

src/features/commands.ts

@@ -19,7 +19,7 @@ import {DotNetAttachItemsProviderFactory, AttachPicker} from './processPicker'
 let channel = vscode.window.createOutputChannel('.NET');
 
 export default function registerCommands(server: OmnisharpServer, extensionPath: string) {
-    let d1 = vscode.commands.registerCommand('o.restart', () => server.restart());
+    let d1 = vscode.commands.registerCommand('o.restart', () => restartOmniSharp(server));
     let d2 = vscode.commands.registerCommand('o.pickProjectAndStart', () => pickProjectAndStart(server));
     let d3 = vscode.commands.registerCommand('o.showOutput', () => server.getChannel().show(vscode.ViewColumn.Three));
     let d4 = vscode.commands.registerCommand('dotnet.restore', () => dotnetRestoreAllProjects(server));
@@ -40,6 +40,15 @@ export default function registerCommands(server: OmnisharpServer, extensionPath:
     return vscode.Disposable.from(d1, d2, d3, d4, d5, d6, d7, d8);
 }
 
+function restartOmniSharp(server: OmnisharpServer) {
+    if (server.isRunning()) {
+        server.restart();
+    }
+    else {
+        server.autoStart('');
+    }
+}
+
 function pickProjectAndStart(server: OmnisharpServer) {
 
     return findLaunchTargets().then(targets => {

src/main.ts

@@ -20,6 +20,7 @@ import reportDiagnostics,{Advisor} from './features/diagnosticsProvider';
 import SignatureHelpProvider from './features/signatureHelpProvider';
 import registerCommands from './features/commands';
 import {StdioOmnisharpServer} from './omnisharp/server';
+import {readOptions} from './omnisharp/options';
 import forwardChanges from './features/changeForwarding';
 import reportStatus from './features/status';
 import * as coreclrdebug from './coreclr-debug/activate';
@@ -28,7 +29,6 @@ import * as vscode from 'vscode';
 import TelemetryReporter from 'vscode-extension-telemetry';
 import {DefinitionMetadataDocumentProvider} from './features/definitionMetadataDocumentProvider';
 
-
 export function activate(context: vscode.ExtensionContext): any {
 
     const extensionId = 'ms-vscode.csharp';
@@ -88,7 +88,11 @@ export function activate(context: vscode.ExtensionContext): any {
 
 	// read and store last solution or folder path
 	disposables.push(server.onBeforeServerStart(path => context.workspaceState.update('lastSolutionPathOrFolder', path)));
-	server.autoStart(context.workspaceState.get<string>('lastSolutionPathOrFolder'));
+
+	const options = readOptions();
+	if (options.autoStart) {
+		server.autoStart(context.workspaceState.get<string>('lastSolutionPathOrFolder'));
+	}
 
 	// stop server on deactivate
 	disposables.push(new vscode.Disposable(() => {

src/omnisharp/omnisharp.ts

@@ -13,12 +13,6 @@
 import * as fs from 'fs-extra-promise';
 import * as path from 'path';
 
-export interface Options {
-    path?: string;
-    useMono?: boolean;
-    loggingLevel?: string;
-}
-
 export enum Flavor {
     CoreCLR,
     Mono,

src/omnisharp/options.ts

@@ -0,0 +1,39 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import * as vscode from 'vscode';
+
+export interface Options {
+    path?: string;
+    useMono?: boolean;
+    loggingLevel?: string;
+    autoStart?: boolean;
+}
+
+export function readOptions(): Options {
+    // Extra effort is taken below to ensure that legacy versions of options
+    // are supported below. In particular, these are:
+    //
+    // - "csharp.omnisharp" -> "omnisharp.path"
+    // - "csharp.omnisharpUsesMono" -> "omnisharp.useMono"
+
+    const omnisharpConfig = vscode.workspace.getConfiguration('omnisharp');
+    const csharpConfig = vscode.workspace.getConfiguration('csharp');
+
+    const path = omnisharpConfig.has('path')
+        ? omnisharpConfig.get<string>('path')
+        : csharpConfig.get<string>('omnisharp');
+
+    const useMono = omnisharpConfig.has('useMono')
+        ? omnisharpConfig.get<boolean>('useMono')
+        : csharpConfig.get<boolean>('omnisharpUsesMono');
+
+    const loggingLevel = omnisharpConfig.get<string>('loggingLevel');
+    const autoStart = omnisharpConfig.get<boolean>('autoStart', true);
+
+    return { path, useMono, loggingLevel, autoStart };
+}

src/omnisharp/server.ts

@@ -13,6 +13,7 @@ import {launchOmniSharp} from './launcher';
 import * as protocol from './protocol';
 import * as omnisharp from './omnisharp';
 import * as download from './download';
+import {readOptions} from './options';
 import {Logger} from './logger';
 import {DelayTracker} from './delayTracker';
 import {LaunchTarget, findLaunchTargets, getDefaultFlavor} from './launcher';
@@ -107,29 +108,6 @@ export abstract class OmnisharpServer {
 		}
 	}
 
-	private _readOptions(): omnisharp.Options {
-		// Extra effort is taken below to ensure that legacy versions of options
-		// are supported below. In particular, these are:
-		//
-		// - "csharp.omnisharp" -> "omnisharp.path"
-		// - "csharp.omnisharpUsesMono" -> "omnisharp.useMono"
-
-		const omnisharpConfig = vscode.workspace.getConfiguration('omnisharp');
-		const csharpConfig = vscode.workspace.getConfiguration('csharp');
-
-		const path = omnisharpConfig.has('path')
-			? omnisharpConfig.get<string>('path')
-			: csharpConfig.get<string>('omnisharp');
-
-		const useMono = omnisharpConfig.has('useMono')
-			? omnisharpConfig.get<boolean>('useMono')
-			: csharpConfig.get<boolean>('omnisharpUsesMono');
-
-		const loggingLevel = omnisharpConfig.get<string>('loggingLevel');
-
-		return { path, useMono, loggingLevel };
-	}
-
     private _recordRequestDelay(requestName: string, elapsedTime: number) {
         let tracker = this._delayTrackers[requestName];
         if (!tracker) {
@@ -252,7 +230,7 @@ export abstract class OmnisharpServer {
 	// --- start, stop, and connect
 
 	private _start(launchTarget: LaunchTarget): Promise<void> {
-		const options = this._readOptions();
+		const options = readOptions();
 
 		let flavor: omnisharp.Flavor;
 		if (options.path !== undefined && options.useMono === true) {
@@ -403,7 +381,7 @@ export abstract class OmnisharpServer {
 			// If there's more than one launch target, we start the server if one of the targets
 			// matches the preferred path. Otherwise, we fire the "MultipleLaunchTargets" event,
 			// which is handled in status.ts to display the launch target selector.
-			if (launchTargets.length > 1) {
+			if (launchTargets.length > 1 && preferredPath) {
 
 				for (let launchTarget of launchTargets) {
 					if (launchTarget.target === preferredPath) {
@@ -425,7 +403,7 @@ export abstract class OmnisharpServer {
 		// Attempt to find launch file path first from options, and then from the default install location.
 		// If OmniSharp can't be found, download it.
 
-		const options = this._readOptions();
+		const options = readOptions();
 		const installDirectory = omnisharp.getInstallDirectory(flavor);
 
 		return new Promise<string>((resolve, reject) => {