fix: log all console output to file

We currently ask users to submit two logs when submitting a new issue:

1. Logs from file, and
2. Logs from output channel (see screenshot below).

In order to simplify the workflow, we should log all console output to file
as well. This has two advantages:

1. We can piece together a more coherent picture by just looking at the log
   file.
2. Users no longer have to submit logs from output channel.

Author: kyliau

server/src/session.ts

@@ -39,10 +39,12 @@ 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 diagnosticsTimeout: NodeJS.Timeout|null = null;
   private isProjectLoading = false;
 
   constructor(options: SessionOptions) {
+    this.logger = options.logger;
     // Create a connection for the server. The connection uses Node's IPC as a transport.
     this.connection = lsp.createConnection();
     this.addProtocolHandlers(this.connection);
@@ -113,6 +115,7 @@ export class Session {
       case ts.server.ProjectLoadingStartEvent:
         this.isProjectLoading = true;
         this.connection.sendNotification(projectLoadingNotification.start);
+        this.logger.info(`Loading new project: ${event.data.reason}`);
         break;
       case ts.server.ProjectLoadingFinishEvent: {
         const {project} = event.data;
@@ -479,39 +482,34 @@ export class Session {
   }
 
   /**
-   * Show an error message.
+   * Show an error message in the remote console and log to file.
    *
    * @param message The message to show.
    */
   error(message: string): void {
     this.connection.console.error(message);
+    this.logger.msg(message, ts.server.Msg.Err);
   }
 
   /**
-   * Show a warning message.
+   * Show a warning message in the remote console and log to file.
    *
    * @param message The message to show.
    */
   warn(message: string): void {
     this.connection.console.warn(message);
+    // ts.server.Msg does not have warning level, so log as info.
+    this.logger.msg(`[WARN] ${message}`, ts.server.Msg.Info);
   }
 
   /**
-   * Show an information message.
+   * Show an information message in the remote console and log to file.
    *
    * @param message The message to show.
    */
   info(message: string): void {
     this.connection.console.info(message);
-  }
-
-  /**
-   * Log a message.
-   *
-   * @param message The message to log.
-   */
-  log(message: string): void {
-    this.connection.console.log(message);
+    this.logger.msg(message, ts.server.Msg.Info);
   }
 
   /**