From b15d6a48cb3d07b82e4c079cc27c85ad76abc497 Mon Sep 17 00:00:00 2001
From: Valera Rozuvan <valera.rozuvan@gmail.com>
Date: Tue, 2 Oct 2018 19:09:51 +0300
Subject: [PATCH] Fix GH#18217 issue for FileLog. (#27430)

* Fix GH#18217 issue for FileLog.

* Refactor FileLog class to not use isEnabled property.
---
 src/typingsInstaller/nodeTypingsInstaller.ts | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/typingsInstaller/nodeTypingsInstaller.ts b/src/typingsInstaller/nodeTypingsInstaller.ts
index 00ee8b4fa19..62bdcfce260 100644
--- a/src/typingsInstaller/nodeTypingsInstaller.ts
+++ b/src/typingsInstaller/nodeTypingsInstaller.ts
@@ -1,5 +1,3 @@
-// tslint:disable no-unnecessary-type-assertion (TODO: tslint can't find node types)
-
 namespace ts.server.typingsInstaller {
     const fs: {
         appendFileSync(file: string, content: string): void
@@ -12,19 +10,20 @@ namespace ts.server.typingsInstaller {
     } = require("path");
 
     class FileLog implements Log {
-        private logEnabled = true;
-        constructor(private readonly logFile?: string) {
+        constructor(private logFile: string | undefined) {
         }
 
         isEnabled = () => {
-            return this.logEnabled && this.logFile !== undefined;
+            return typeof this.logFile === "string";
         }
         writeLine = (text: string) => {
+            if (typeof this.logFile !== "string") return;
+
             try {
-                fs.appendFileSync(this.logFile!, `[${nowString()}] ${text}${sys.newLine}`); // TODO: GH#18217
+                fs.appendFileSync(this.logFile, `[${nowString()}] ${text}${sys.newLine}`);
             }
             catch (e) {
-                this.logEnabled = false;
+                this.logFile = undefined;
             }
         }
     }