fix: add close handler for lsProcess

Author: aminya

lib/auto-languageclient.ts

@@ -368,6 +368,7 @@ export default class AutoLanguageClient {
 
   private captureServerErrors(lsProcess: LanguageServerProcess, projectPath: string): void {
     lsProcess.on('error', (err) => this.handleSpawnFailure(err));
+    lsProcess.on("close", (...args) => this.handleCloseFailure(...args));
     lsProcess.on('exit', (code, signal) => this.logger.debug(`exit: code ${code} signal ${signal}`));
     lsProcess.stderr.setEncoding('utf8');
     lsProcess.stderr.on('data', (chunk: Buffer) => {
@@ -391,6 +392,14 @@ export default class AutoLanguageClient {
     );
   }
 
+  private handleCloseFailure(code: number | null, signal: NodeJS.Signals | null): void {
+    if (code !== 0 && signal === null) {
+      atom.notifications.addError(
+        `${this.getServerName()} language server for ${this.getLanguageName()} was closed with code: ${code}.`
+      );
+    }
+  }
+
   /** Creates the RPC connection which can be ipc, socket or stdio */
   private createRpcConnection(lsProcess: LanguageServerProcess): rpc.MessageConnection {
     let reader: rpc.MessageReader;

lib/server-manager.ts

@@ -24,8 +24,10 @@ export interface LanguageServerProcess extends EventEmitter {
   pid: number;
 
   kill(signal?: NodeJS.Signals | number): void;
+  on(event: 'close', listener: (code: number | null, signal: NodeJS.Signals | null) => void): this;
+  on(event: 'disconnect', listener: () => void): this;
   on(event: 'error', listener: (err: Error) => void): this;
-  on(event: 'exit', listener: (code: number, signal: NodeJS.Signals | number) => void): this;
+  on(event: 'exit', listener: (code: number | null, signal: NodeJS.Signals | null) => void): this;
 }
 
 /** The necessary elements for a server that has started or is starting. */