feat: Prompt to use the Ivy Language Service if VE is detected

In order to drive adoption of the new Ivy Language Service before it
becomes the default in v12, this commit adds a prompt for users to
enable it if they are using `@angular/core` v9+.

Fixes #1095

Author: atscott

client/src/client.ts

@@ -11,7 +11,7 @@ import * as path from 'path';
 import * as vscode from 'vscode';
 import * as lsp from 'vscode-languageclient/node';
 
-import {ProjectLoadingFinish, ProjectLoadingStart, SuggestStrictMode, SuggestStrictModeParams} from '../common/notifications';
+import {ProjectLoadingFinish, ProjectLoadingStart, SuggestIvyLanguageService, SuggestIvyLanguageServiceParams, SuggestStrictMode, SuggestStrictModeParams} from '../common/notifications';
 import {NgccProgress, NgccProgressToken, NgccProgressType} from '../common/progress';
 
 import {ProgressReporter} from './progress-reporter';
@@ -136,7 +136,29 @@ function registerNotificationHandlers(
         }
       });
 
-  context.subscriptions.push(disposable1, disposable2);
+  const disposable3 = client.onNotification(
+      SuggestIvyLanguageService, async (params: SuggestIvyLanguageServiceParams) => {
+        const config = vscode.workspace.getConfiguration();
+        if (config.get('angular.enable-experimental-ivy-prompt') === false) {
+          return;
+        }
+
+        const enableIvy = 'Enable';
+        const doNotPromptAgain = 'Do not show this again';
+        const selection = await vscode.window.showInformationMessage(
+            params.message,
+            enableIvy,
+            doNotPromptAgain,
+        );
+        if (selection === enableIvy) {
+          config.update('angular.experimental-ivy', true, vscode.ConfigurationTarget.Global);
+        } else if (selection === doNotPromptAgain) {
+          config.update(
+              'angular.enable-experimental-ivy-prompt', false, vscode.ConfigurationTarget.Global);
+        }
+      });
+
+  context.subscriptions.push(disposable1, disposable2, disposable3);
 }
 
 function registerProgressHandlers(client: lsp.LanguageClient, context: vscode.ExtensionContext) {

common/notifications.ts

@@ -26,3 +26,10 @@ export interface SuggestStrictModeParams {
 
 export const SuggestStrictMode =
     new NotificationType<SuggestStrictModeParams>('angular/suggestStrictMode');
+
+export interface SuggestIvyLanguageServiceParams {
+  message: string;
+}
+
+export const SuggestIvyLanguageService =
+    new NotificationType<SuggestIvyLanguageServiceParams>('angular/suggestIvyLanguageServiceMode');

integration/lsp/test_utils.ts

@@ -30,7 +30,7 @@ export function createConnection(serverOptions: ServerOptions): MessageConnectio
     '--tsProbeLocations',
     PACKAGE_ROOT,
     '--ngProbeLocations',
-    SERVER_PATH,
+    [SERVER_PATH, PROJECT_PATH].join(','),
   ];
   if (serverOptions.ivy) {
     argv.push('--experimental-ivy');

integration/lsp/viewengine_spec.ts

@@ -8,6 +8,7 @@
 
 import {MessageConnection} from 'vscode-jsonrpc';
 import * as lsp from 'vscode-languageserver-protocol';
+import {SuggestIvyLanguageService, SuggestIvyLanguageServiceParams} from '../../common/notifications';
 import {APP_COMPONENT, createConnection, FOO_TEMPLATE, initializeServer, openTextDocument} from './test_utils';
 
 describe('Angular language server', () => {
@@ -107,6 +108,12 @@ describe('Angular language server', () => {
     expect(diagnostics.length).toBe(1);
     expect(diagnostics[0].message).toContain(`Identifier 'doesnotexist' is not defined.`);
   });
+
+  it('should prompt to enable Ivy Language Service', async () => {
+    openTextDocument(client, APP_COMPONENT);
+    const message = await onSuggestIvyLanguageService(client);
+    expect(message).toContain('Would you like to enable the new Ivy-native language service');
+  });
 });
 
 describe('initialization', () => {
@@ -138,3 +145,11 @@ describe('initialization', () => {
     client.dispose();
   });
 });
+
+function onSuggestIvyLanguageService(client: MessageConnection): Promise<string> {
+  return new Promise(resolve => {
+    client.onNotification(SuggestIvyLanguageService, (params: SuggestIvyLanguageServiceParams) => {
+      resolve(params.message);
+    });
+  });
+}

package.json

@@ -57,6 +57,11 @@
           "default": false,
           "description": "This is an experimental feature that enables the Ivy language service."
         },
+        "angular.enable-experimental-ivy-prompt": {
+          "type": "boolean",
+          "default": true,
+          "description": "Prompt to enable the Ivy language service for the workspace when View Engine is in use."
+        },
         "angular.trace.server": {
           "type": "string",
           "scope": "window",
@@ -159,4 +164,4 @@
     "type": "git",
     "url": "https://github.com/angular/vscode-ng-language-service"
   }
-}
+}

server/src/server.ts

@@ -37,7 +37,7 @@ const session = new Session({
   host,
   logger,
   ngPlugin: ng.name,
-  ngProbeLocation: ng.resolvedPath,
+  resolvedNgLsPath: ng.resolvedPath,
   ivy: options.ivy,
   logToConsole: options.logToConsole,
 });

server/src/session.ts

@@ -10,20 +10,21 @@ import * as ts from 'typescript/lib/tsserverlibrary';
 import * as lsp from 'vscode-languageserver/node';
 
 import {ServerOptions} from '../common/initialize';
-import {ProjectLanguageService, ProjectLoadingFinish, ProjectLoadingStart, SuggestStrictMode} from '../common/notifications';
+import {ProjectLanguageService, ProjectLoadingFinish, ProjectLoadingStart, SuggestIvyLanguageService, SuggestStrictMode} from '../common/notifications';
 import {NgccProgressToken, NgccProgressType} from '../common/progress';
 
 import {readNgCompletionData, tsCompletionEntryToLspCompletionItem} from './completion';
 import {tsDiagnosticToLspDiagnostic} from './diagnostic';
 import {resolveAndRunNgcc} from './ngcc';
 import {ServerHost} from './server_host';
 import {filePathToUri, isConfiguredProject, lspPositionToTsPosition, lspRangeToTsPositions, tsTextSpanToLspRange, uriToFilePath} from './utils';
+import {resolve, Version} from './version_provider';
 
 export interface SessionOptions {
   host: ServerHost;
   logger: ts.server.Logger;
   ngPlugin: string;
-  ngProbeLocation: string;
+  resolvedNgLsPath: string;
   ivy: boolean;
   logToConsole: boolean;
 }
@@ -44,6 +45,7 @@ export class Session {
   private readonly connection: lsp.Connection;
   private readonly projectService: ts.server.ProjectService;
   private readonly logger: ts.server.Logger;
+  private readonly angularCoreVersionMap = new WeakMap<ts.server.Project, Version>();
   private readonly ivy: boolean;
   private readonly configuredProjToExternalProj = new Map<string, string>();
   private readonly logToConsole: boolean;
@@ -83,7 +85,7 @@ export class Session {
       suppressDiagnosticEvents: true,
       eventHandler: (e) => this.handleProjectServiceEvent(e),
       globalPlugins: [options.ngPlugin],
-      pluginProbeLocations: [options.ngProbeLocation],
+      pluginProbeLocations: [options.resolvedNgLsPath],
       allowLocalPluginLoads: false,  // do not load plugins from tsconfig.json
     });
 
@@ -836,7 +838,8 @@ export class Session {
       return;
     }
 
-    if (!this.checkIsAngularProject(project)) {
+    const coreDts = this.checkIsAngularProject(project);
+    if (coreDts === undefined) {
       return;
     }
 
@@ -850,22 +853,40 @@ export class Session {
     } else {
       // Immediately enable Legacy/ViewEngine language service
       this.info(`Enabling VE language service for ${projectName}.`);
+      this.promptToEnableIvyIfAvailable(project, coreDts);
+    }
+  }
+
+  private promptToEnableIvyIfAvailable(
+      project: ts.server.Project, coreDts: ts.server.NormalizedPath) {
+    let angularCoreVersion = this.angularCoreVersionMap.get(project);
+    if (angularCoreVersion === undefined) {
+      angularCoreVersion = resolve('@angular/core', coreDts)?.version;
+    }
+
+    if (angularCoreVersion !== undefined && !this.ivy && angularCoreVersion.major >= 9) {
+      this.connection.sendNotification(SuggestIvyLanguageService, {
+        message:
+            'Would you like to enable the new Ivy-native language service to get the latest features and bug fixes?',
+      });
     }
   }
 
   /**
    * Determine if the specified `project` is Angular, and disable the language
    * service if not.
+   *
+   * @returns The `ts.server.NormalizedPath` to the `@angular/core/core.d.ts` file.
    */
-  private checkIsAngularProject(project: ts.server.Project): boolean {
+  private checkIsAngularProject(project: ts.server.Project): ts.server.NormalizedPath|undefined {
     const {projectName} = project;
     const NG_CORE = '@angular/core/core.d.ts';
-
-    const isAngularProject = project.hasRoots() && !project.isNonTsProject() &&
-        project.getFileNames().some(f => f.endsWith(NG_CORE));
+    const ngCoreDts = project.getFileNames().find(f => f.endsWith(NG_CORE));
+    const isAngularProject =
+        project.hasRoots() && !project.isNonTsProject() && ngCoreDts !== undefined;
 
     if (isAngularProject) {
-      return true;
+      return ngCoreDts;
     }
 
     project.disableLanguageService();
@@ -879,7 +900,7 @@ export class Session {
           `Please check your tsconfig.json to make sure 'node_modules' directory is not excluded.`);
     }
 
-    return false;
+    return undefined;
   }
 }
 

server/src/version_provider.ts

@@ -20,7 +20,7 @@ interface NodeModule {
   version: Version;
 }
 
-function resolve(packageName: string, location: string, rootPackage?: string): NodeModule|
+export function resolve(packageName: string, location: string, rootPackage?: string): NodeModule|
     undefined {
   rootPackage = rootPackage || packageName;
   try {