Define global logger instance to be used for all logging

Summary:
The advantage of this is that anyone can now log without needing to carry around a Logger object.
Primary reason is for making metrics less intrusive in the codebase.

Reviewed By: passy

Differential Revision: D13671368

fbshipit-source-id: 162ab1351a124683aef13983fc3bcec01385cd1a

src/__tests__/App.electron.js

@@ -10,14 +10,14 @@ import {Provider} from 'react-redux';
 import renderer from 'react-test-renderer';
 import reducers from '../reducers/index.js';
 import configureStore from 'redux-mock-store';
-import Logger from '../fb-stubs/Logger.js';
+import {init as initLogger} from '../fb-stubs/Logger';
 import BugReporter from '../fb-stubs/BugReporter.js';
 
 // create redux store with initial state
 const mockStore = configureStore([])(reducers(undefined, {type: 'INIT'}));
 
 test('Empty app state matches snapshot', () => {
-  const logger = new Logger();
+  const logger = initLogger();
   const bugReporter = new BugReporter(logger, mockStore);
 
   const component = renderer.create(

src/__tests__/server.electron.js

@@ -6,7 +6,7 @@
  */
 
 import Server, {SECURE_PORT, INSECURE_PORT} from '../server.js';
-import LogManager from '../fb-stubs/Logger';
+import {init as initLogger} from '../fb-stubs/Logger';
 import reducers from '../reducers/index.js';
 import configureStore from 'redux-mock-store';
 import path from 'path';
@@ -23,7 +23,8 @@ beforeAll(() => {
     fs.mkdirSync(flipperDir);
   }
 
-  server = new Server(new LogManager(), mockStore);
+  const logger = initLogger();
+  server = new Server(logger, mockStore);
   return server.init();
 });
 

src/dispatcher/androidDevice.js

@@ -81,11 +81,7 @@ export default (store: Store, logger: Logger) => {
       },
     );
   }
-  const clientPromise = recordSuccessMetric(
-    createClient(),
-    'createADBClient',
-    logger,
-  );
+  const clientPromise = recordSuccessMetric(createClient(), 'createADBClient');
 
   const watchAndroidDevices = () => {
     // get emulators

src/fb-stubs/BugReporter.js

@@ -5,7 +5,7 @@
  * @format
  */
 
-import LogManager from './Logger';
+import type LogManager from './Logger';
 
 import type {Store} from '../reducers/index.js';
 

src/fb-stubs/Logger.js

@@ -9,6 +9,8 @@ export type LogTypes = 'error' | 'warn' | 'info' | 'debug';
 export type TrackType = 'duration' | 'usage' | 'performance' | 'success-rate';
 import ScribeLogger from './ScribeLogger';
 
+var instance: ?LogManager = null;
+
 export default class LogManager {
   constructor(store: ?Store) {
     this.scribeLogger = new ScribeLogger(this);
@@ -28,3 +30,20 @@ export default class LogManager {
 
   debug(data: any, category: string) {}
 }
+
+export function init(store: Store): LogManager {
+  if (instance) {
+    throw new Error('Attempted to initialize Logger when already initialized');
+  }
+  instance = new LogManager(store);
+  return instance;
+}
+
+export function getInstance(): LogManager {
+  if (!instance) {
+    throw new Error(
+      'Requested Logger instance without initializing it. Make sure init() is called at app start',
+    );
+  }
+  return instance;
+}

src/init.js

@@ -10,7 +10,7 @@ import ReactDOM from 'react-dom';
 import {ContextMenuProvider} from 'flipper';
 import {precachedIcons} from './utils/icons.js';
 import GK from './fb-stubs/GK.js';
-import Logger from './fb-stubs/Logger.js';
+import {init as initLogger} from './fb-stubs/Logger';
 import App from './App.js';
 import BugReporter from './fb-stubs/BugReporter.js';
 import {createStore} from 'redux';
@@ -26,7 +26,7 @@ const store = createStore(
 );
 persistStore(store);
 
-const logger = new Logger(store);
+const logger = initLogger(store);
 const bugReporter = new BugReporter(logger, store);
 dispatcher(store, logger);
 GK.init();

src/server.js

@@ -185,7 +185,6 @@ export default class Server extends EventEmitter {
                 destination,
               ),
               'processCertificateSigningRequest',
-              this.logger,
             )
               .then(result => {
                 subscriber.onComplete({

src/utils/__tests__/metrics.node.js

@@ -1,58 +0,0 @@
-/**
- * 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 {recordSuccessMetric} from '../metrics';
-import type Logger from '../../fb-stubs/Logger';
-
-//$FlowFixMe pretend logger is the right type
-const logger: Logger = {
-  track: jest.fn(),
-};
-
-beforeAll(() => {
-  logger.track.mockClear();
-});
-
-test('Wrapping a successful promise preserves result and logs correctly', () => {
-  const successPromise = Promise.resolve('Yay!');
-  const wrappedPromise = recordSuccessMetric(
-    successPromise,
-    'test metric',
-    logger,
-  );
-  return wrappedPromise
-    .then(wrappedValue => {
-      expect(wrappedValue).toBe('Yay!');
-    })
-    .then(() => {
-      expect(logger.track).toHaveBeenCalledWith(
-        'success-rate',
-        'test metric',
-        1,
-      );
-    });
-});
-
-test('Wrapping a rejected promise preserves result and logs correctly', () => {
-  const successPromise = Promise.reject('Oh no!');
-  const wrappedPromise = recordSuccessMetric(
-    successPromise,
-    'test metric',
-    logger,
-  );
-  expect.assertions(2); // Make sure to fail if catch block isn't visited
-  return wrappedPromise
-    .catch(wrappedValue => {
-      expect(wrappedValue).toBe('Oh no!');
-    })
-    .then(() => {
-      expect(logger.track).toHaveBeenCalledWith(
-        'success-rate',
-        'test metric',
-        0,
-      );
-    });
-});

src/utils/metrics.js

@@ -5,7 +5,7 @@
  * @format
  */
 
-import type Logger from '../fb-stubs/Logger';
+import {getInstance} from '../fb-stubs/Logger';
 
 /*
  * Wraps a Promise, preserving it's functionality but logging the success or
@@ -15,15 +15,14 @@ import type Logger from '../fb-stubs/Logger';
 export function recordSuccessMetric(
   promise: Promise<*>,
   name: string,
-  logger: Logger,
 ): Promise<*> {
   return promise.then(
     fulfilledValue => {
-      logger.track('success-rate', name, 1);
+      getInstance().track('success-rate', name, 1);
       return fulfilledValue;
     },
     rejectionReason => {
-      logger.track('success-rate', name, 0);
+      getInstance().track('success-rate', name, 0);
       return Promise.reject(rejectionReason);
     },
   );