Add a new API to wait for standard server ready (#2461)

- Add waitForServerReady() which returns a promise. The promise will
  only be resolved when the standard server is ready.

Signed-off-by: sheche <sheche@microsoft.com>

Author: jdneo

src/apiManager.ts

@@ -16,6 +16,7 @@ class ApiManager {
     private onDidClasspathUpdateEmitter: Emitter<Uri> = new Emitter<Uri>();
     private onDidServerModeChangeEmitter: Emitter<ServerMode> = new Emitter<ServerMode>();
     private onDidProjectsImportEmitter: Emitter<Uri[]> = new Emitter<Uri[]>();
+    private serverReadyPromiseResolve: (result: boolean) => void;
 
     public initialize(requirements: RequirementsData, serverMode: ServerMode): void {
         const getDocumentSymbols: getDocumentSymbolsCommand = getDocumentSymbolsProvider();
@@ -37,6 +38,13 @@ class ApiManager {
         const onDidServerModeChange = this.onDidServerModeChangeEmitter.event;
         const onDidProjectsImport = this.onDidProjectsImportEmitter.event;
 
+        const serverReadyPromise: Promise<boolean> = new Promise<boolean>((resolve) => {
+            this.serverReadyPromiseResolve = resolve;
+        });
+        const waitForServerReady = async () => {
+            return serverReadyPromise;
+        };
+
         this.api = {
             apiVersion: ExtensionApiVersion,
             javaRequirement: requirements,
@@ -51,6 +59,7 @@ class ApiManager {
             serverMode,
             onDidServerModeChange,
             onDidProjectsImport,
+            waitForServerReady,
         };
     }
 
@@ -81,6 +90,10 @@ class ApiManager {
     public updateStatus(status: ClientStatus): void {
         this.api.status = status;
     }
+
+    public standardServerReady(): void {
+        this.serverReadyPromiseResolve(true);
+    }
 }
 
 export const apiManager: ApiManager = new ApiManager();

src/extension.api.ts

@@ -73,7 +73,7 @@ export enum ClientStatus {
 	Stopping = "Stopping",
 }
 
-export const ExtensionApiVersion = '0.6';
+export const ExtensionApiVersion = '0.7';
 
 export interface ExtensionAPI {
 	readonly apiVersion: string;
@@ -110,4 +110,11 @@ export interface ExtensionAPI {
 	 * An event which fires when the server mode has been switched.
 	 */
 	readonly onDidServerModeChange: Event<ServerMode>;
+
+	/**
+	 * A promise that will be resolved when the standard language server is ready.
+	 * @since API version 0.7
+	 * @since extension version 1.7.0
+	 */
+	readonly waitForServerReady: () => Promise<boolean>;
 }

src/standardLanguageClient.ts

@@ -108,6 +108,7 @@ export class StandardLanguageClient {
 					case 'ServiceReady':
 						apiManager.updateServerMode(ServerMode.STANDARD);
 						apiManager.fireDidServerModeChange(ServerMode.STANDARD);
+						apiManager.standardServerReady();
 						activationProgressNotification.hide();
 						if (!hasImported) {
 							showImportFinishNotification(context);

test/standard-mode-suite/publicApi.test.ts

@@ -163,6 +163,11 @@ suite('Public APIs - Standard', () => {
 		});
 	});
 
+	test('waitForServerReady() should work', async function () {
+		const api: ExtensionAPI = extensions.getExtension('redhat.java').exports;
+		await api.waitForServerReady();
+	});
+
 	suiteTeardown(async function() {
 		// revert the pom content
 		const pomContent: string = await fse.readFile(pomPath, 'utf-8');