refactor: remove traceToConsole feature in Logger

Currently if users ask for logging to disabled (by not providing a filename
for the log file), the Logger defaults to writing to console.

In practice, this feature is not used at all. If users do not want logging,
then we should just disable logging entirely.

Author: kyliau

server/src/logger.ts

@@ -38,7 +38,7 @@ export interface LoggerOptions {
  * Create a logger instance to write to file.
  * @param options Logging options.
  */
-export function createLogger(options: LoggerOptions): Logger {
+export function createLogger(options: LoggerOptions): ts.server.Logger {
   let logLevel: ts.server.LogLevel;
   switch (options.logVerbosity) {
     case 'requestTime':
@@ -55,9 +55,7 @@ export function createLogger(options: LoggerOptions): Logger {
       logLevel = ts.server.LogLevel.terse;
       break;
   }
-  // If logFile is not provided then just trace to console.
-  const traceToConsole = !options.logFile;
-  return new Logger(traceToConsole, logLevel, options.logFile);
+  return new Logger(logLevel, options.logFile);
 }
 
 // TODO: Code below is from TypeScript's repository. Maybe create our own
@@ -72,17 +70,17 @@ function nowString() {
   return `${d.getHours()}:${d.getMinutes()}:${d.getSeconds()}.${d.getMilliseconds()}`;
 }
 
-export class Logger implements ts.server.Logger {
-  private fd = -1;
+class Logger implements ts.server.Logger {
+  private readonly fd: number;
   private seq = 0;
   private inGroup = false;
   private firstInGroup = true;
 
   constructor(
-      private readonly traceToConsole: boolean,
       private readonly level: ts.server.LogLevel,
       private readonly logFilename?: string,
   ) {
+    this.fd = -1;
     if (logFilename) {
       try {
         const dir = path.dirname(logFilename);
@@ -101,7 +99,7 @@ export class Logger implements ts.server.Logger {
   }
 
   close() {
-    if (this.fd >= 0) {
+    if (this.loggingEnabled()) {
       fs.close(this.fd, noop);
     }
   }
@@ -118,10 +116,6 @@ export class Logger implements ts.server.Logger {
     this.msg(s, ts.server.Msg.Info);
   }
 
-  err(s: string) {
-    this.msg(s, ts.server.Msg.Err);
-  }
-
   startGroup() {
     this.inGroup = true;
     this.firstInGroup = true;
@@ -132,39 +126,29 @@ export class Logger implements ts.server.Logger {
   }
 
   loggingEnabled() {
-    return !!this.logFilename || this.traceToConsole;
+    return this.fd >= 0;
   }
 
   hasLevel(level: ts.server.LogLevel) {
     return this.loggingEnabled() && this.level >= level;
   }
 
   msg(s: string, type: ts.server.Msg = ts.server.Msg.Err) {
-    if (!this.canWrite) return;
+    if (!this.loggingEnabled()) {
+      return;
+    }
 
     s = `[${nowString()}] ${s}\n`;
     if (!this.inGroup || this.firstInGroup) {
       const prefix = Logger.padStringRight(type + ' ' + this.seq.toString(), '          ');
       s = prefix + s;
     }
-    this.write(s);
-    if (!this.inGroup) {
-      this.seq++;
-    }
-  }
 
-  private get canWrite() {
-    return this.fd >= 0 || this.traceToConsole;
-  }
+    const buf = Buffer.from(s);
+    fs.writeSync(this.fd, buf, 0, buf.length);
 
-  private write(s: string) {
-    if (this.fd >= 0) {
-      const buf = Buffer.from(s);
-      // tslint:disable-next-line no-null-keyword
-      fs.writeSync(this.fd, buf, 0, buf.length, /*position*/ null!);  // TODO: GH#18217
-    }
-    if (this.traceToConsole) {
-      console.warn(s);
+    if (!this.inGroup) {
+      this.seq++;
     }
   }
 }

server/src/session.ts

@@ -13,13 +13,12 @@ import * as notification from '../../common/out/notifications';
 
 import {tsCompletionEntryToLspCompletionItem} from './completion';
 import {tsDiagnosticToLspDiagnostic} from './diagnostic';
-import {Logger} from './logger';
 import {ServerHost} from './server_host';
 import {filePathToUri, lspPositionToTsPosition, lspRangeToTsPositions, tsTextSpanToLspRange, uriToFilePath} from './utils';
 
 export interface SessionOptions {
   host: ServerHost;
-  logger: Logger;
+  logger: ts.server.Logger;
   ngPlugin: string;
   ngProbeLocation: string;
   ivy: boolean;
@@ -40,7 +39,7 @@ const EMPTY_RANGE = lsp.Range.create(0, 0, 0, 0);
 export class Session {
   private readonly connection: lsp.IConnection;
   private readonly projectService: ts.server.ProjectService;
-  private readonly logger: Logger;
+  private readonly logger: ts.server.Logger;
   private readonly ivy: boolean;
   private diagnosticsTimeout: NodeJS.Timeout|null = null;
   private isProjectLoading = false;