[Code] improve lsp proxy state management (#47580) (#47651)

x-pack/legacy/plugins/code/server/lsp/abstract_launcher.ts

@@ -43,6 +43,8 @@ export abstract class AbstractLauncher implements ILanguageServerLauncher {
       log.debug('Detach mode, expected language server launch externally');
       proxy.onConnected(() => {
         this.running = true;
+        // reset spawn times
+        this.spawnTimes = 0;
       });
       proxy.onDisconnected(() => {
         this.running = false;
@@ -81,6 +83,8 @@ export abstract class AbstractLauncher implements ILanguageServerLauncher {
     await new Promise((resolve, reject) => {
       proxy.onConnected(() => {
         this.proxyConnected = true;
+        // reset spawn times
+        this.spawnTimes = 0;
         resolve();
       });
       this.launchReject = err => {

x-pack/legacy/plugins/code/server/lsp/proxy.ts

@@ -93,9 +93,10 @@ export class LanguageServerProxy implements ILanguageServerHandler {
         this.eventEmitter.on('err', error =>
           reject(new ResponseError(InternalError, 'Server error', error))
         );
-        this.eventEmitter.on('exit', () =>
-          reject(new ResponseError(RequestCancelled, 'Server closed'))
-        );
+        this.eventEmitter.on('exit', () => {
+          reject(new ResponseError(RequestCancelled, 'Server closed'));
+          this.initialized = false;
+        });
         this.eventEmitter.on('connect', () => resolve(this.clientConnection!));
       });
     }
@@ -164,6 +165,7 @@ export class LanguageServerProxy implements ILanguageServerHandler {
       clientConn.sendNotification(ExitNotification.type);
     }
     this.eventEmitter.emit('exit');
+    this.initialized = false;
   }
 
   public startServerConnection() {
@@ -246,6 +248,7 @@ export class LanguageServerProxy implements ILanguageServerHandler {
 
   private onSocketClosed() {
     this.clientConnection = null;
+    this.initialized = false;
     this.eventEmitter.emit('close');
   }
 

x-pack/legacy/plugins/code/server/lsp/request_expander.ts

@@ -56,9 +56,12 @@ export class RequestExpander implements ILanguageServerHandler {
     readonly log: Logger
   ) {
     this.proxy = proxy;
-    proxy.onDisconnected(() => {
+    const clearListener = () => {
+      this.log.debug('proxy disconnected, clearing workspace status');
       this.workspaces.clear();
-    });
+    };
+    proxy.onDisconnected(clearListener);
+    proxy.onExit(clearListener);
     this.workspaceRoot = fs.realpathSync(this.serverOptions.workspacePath);
   }
 
@@ -260,9 +263,10 @@ export class RequestExpander implements ILanguageServerHandler {
   }
 
   initializeState(workspaceDir: string): WorkspaceStatus {
-    if (this.hasWorkspacePath(workspaceDir)) {
-      return this.getWorkspace(workspaceDir).status;
+    const ws = this.getWorkspace(workspaceDir);
+    if (ws.status === WorkspaceStatus.Uninitialized) {
+      ws.initPromise = Cancelable.fromPromise(this.initialize(workspaceDir));
     }
-    return WorkspaceStatus.Uninitialized;
+    return ws.status;
   }
 }

x-pack/legacy/plugins/code/server/lsp/workspace_handler.ts

@@ -158,6 +158,9 @@ export class WorkspaceHandler {
   }
 
   public handleResponse(request: LspRequest, response: ResponseMessage): ResponseMessage {
+    if (!response.result) {
+      return response;
+    }
     const { method } = request;
     switch (method) {
       case 'textDocument/hover': {