Add API so that extensions can configure TS Server plugins

Fixes #63181

This is a replacement for the `_typescript.configurePlugin` command. Using a command, it is easy to forget to check if the js-ts extension is active before executing it. Using an actual api prevents this  and also allows better typing

extensions/typescript-language-features/src/api.ts

@@ -4,24 +4,31 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as vscode from 'vscode';
+import { PluginManager } from './utils/plugins';
 
-interface ApiV0 {
- readonly onCompletionAccepted: vscode.Event<vscode.CompletionItem & { metadata?: any }>;
+class ApiV0 {
+ public constructor(
+ public readonly onCompletionAccepted: vscode.Event<vscode.CompletionItem & { metadata?: any }>,
+ private readonly _pluginManager: PluginManager,
+ ) { }
+
+ configurePlugin(pluginId: string, configuration: {}): void {
+ this._pluginManager.setConfiguration(pluginId, configuration);
+ }
 }
 
 export interface Api {
  getAPI(version: 0): ApiV0 | undefined;
 }
 
 export function getExtensionApi(
- onCompletionAccepted: vscode.Event<vscode.CompletionItem>
+ onCompletionAccepted: vscode.Event<vscode.CompletionItem>,
+ pluginManager: PluginManager,
 ): Api {
  return {
  getAPI(version) {
  if (version === 0) {
- return {
- onCompletionAccepted: onCompletionAccepted
- } as ApiV0;
+ return new ApiV0(onCompletionAccepted, pluginManager);
  }
  return undefined;
  }

extensions/typescript-language-features/src/extension.ts

@@ -69,7 +69,7 @@ export function activate(
  }
  }
 
- return getExtensionApi(onCompletionAccepted.event);
+ return getExtensionApi(onCompletionAccepted.event, pluginManager);
 }
 
 function createLazyClientHost(