Add explicit StubLogger option for tests

Summary:
A bit ugly to have test-only code in prod logic,
but we don't need any of the logger logic in tests
and by pulling out the `StubLogger`, we can avoid
loading Electron during tests.

Reviewed By: jknoxville

Differential Revision: D17808479

fbshipit-source-id: d2295d7bbca2f09c3f23389ad9443648757d8d03

src/fb-interfaces/Logger.tsx

@@ -13,6 +13,11 @@ export type TrackType =
   | 'success-rate'
   | 'operation-cancelled';
 
+export type Args = {
+  isHeadless?: boolean;
+  isTest?: boolean;
+};
+
 export interface Logger {
   track(type: TrackType, event: string, data?: any, plugin?: string): void;
 

src/fb-stubs/Logger.tsx

@@ -5,37 +5,13 @@
  * @format
  */
 
-import {TrackType, Logger} from '../fb-interfaces/Logger';
+import {Logger, Args} from '../fb-interfaces/Logger';
+import StubLogger from '../utils/StubLogger';
 import {Store} from '../reducers/index';
-import ScribeLogger from './ScribeLogger';
 
 let instance: StubLogger | null = null;
 
-type Args = {
-  isHeadless?: boolean;
-};
-
-class StubLogger implements Logger {
-  constructor(store: Store, args?: Args) {
-    this.scribeLogger = new ScribeLogger(this);
-  }
-
-  scribeLogger: ScribeLogger;
-
-  track(type: TrackType, event: string, data?: any, plugin?: string) {}
-
-  trackTimeSince(mark: string, eventName?: string) {}
-
-  info(data: any, category: string) {}
-
-  warn(data: any, category: string) {}
-
-  error(data: any, category: string) {}
-
-  debug(data: any, category: string) {}
-}
-
-export function init(store: Store, args?: Args): Logger {
+export function init(store: Store, _args?: Args): Logger {
   if (instance) {
     throw new Error('Attempted to initialize Logger when already initialized');
   }

src/utils/StubLogger.tsx

@@ -0,0 +1,30 @@
+/**
+ * Copyright 2018-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ */
+
+import {Logger, Args, TrackType} from '../fb-interfaces/Logger';
+import ScribeLogger from '../fb-stubs/ScribeLogger';
+import {Store} from '../reducers/index';
+
+export default class StubLogger implements Logger {
+  constructor(_store: Store, _args?: Args) {
+    this.scribeLogger = new ScribeLogger(this);
+  }
+
+  scribeLogger: ScribeLogger;
+
+  track(_type: TrackType, _event: string, _data?: any, _plugin?: string) {}
+
+  trackTimeSince(_mark: string, _eventName?: string) {}
+
+  info(_data: any, _category: string) {}
+
+  warn(_data: any, _category: string) {}
+
+  error(_data: any, _category: string) {}
+
+  debug(_data: any, _category: string) {}
+}