'silent' option for Activity events

Summary: Activity events now have a `silent` boolean option that specifies whether or not the event phases are to be logged to the console. Defaults to `false`, preserving current behaviour for events that do not explicitly have this option set.

Reviewed By: davidaurelio

Differential Revision: D3810802

fbshipit-source-id: 38d14b9e6c6502fbc73eece9466f20b60d19965e

packager/react-packager/src/Activity/Types.js

@@ -12,7 +12,8 @@
 'use strict';
 
 export type EventOptions = {
-  telemetric: boolean,
+  telemetric?: boolean,
+  silent?: boolean,
 };
 
 export type Event = {

packager/react-packager/src/Activity/__tests__/Activity-test.js

@@ -28,7 +28,7 @@ describe('Activity', () => {
   });
 
   describe('startEvent', () => {
-    it('writes a START event out to the console', () => {
+    it('writes the "START" phase of non-silent events to the console', () => {
       const EVENT_NAME = 'EVENT_NAME';
       const DATA = {someData: 42};
 
@@ -43,10 +43,21 @@ describe('Activity', () => {
       expect(consoleMsg).toContain(EVENT_NAME);
       expect(consoleMsg).toContain(JSON.stringify(DATA));
     });
+
+    it('does not write the "START" phase of silent events to the console', () => {
+      const EVENT_NAME = 'EVENT_NAME';
+      const DATA = {someData: 42};
+
+      Activity.startEvent(EVENT_NAME, DATA, {silent: true});
+      jest.runOnlyPendingTimers();
+
+      // eslint-disable-next-line no-console-disallow
+      expect(console.log.mock.calls.length).toBe(0);
+    });
   });
 
   describe('endEvent', () => {
-    it('writes an END event out to the console', () => {
+    it('writes the "END" phase of non-silent events to the console', () => {
       const EVENT_NAME = 'EVENT_NAME';
       const DATA = {someData: 42};
 
@@ -63,6 +74,18 @@ describe('Activity', () => {
       expect(consoleMsg).toContain(JSON.stringify(DATA));
     });
 
+    it('does not write the "END" phase of silent events to the console', () => {
+      const EVENT_NAME = 'EVENT_NAME';
+      const DATA = {someData: 42};
+
+      const eventID = Activity.startEvent(EVENT_NAME, DATA, {silent: true});
+      Activity.endEvent(eventID);
+      jest.runOnlyPendingTimers();
+
+      // eslint-disable-next-line no-console-disallow
+      expect(console.log.mock.calls.length).toBe(0);
+    });
+
     it('throws when called with an invalid eventId', () => {
       expect(() => Activity.endEvent(42)).toThrow();
     });

packager/react-packager/src/Activity/index.js

@@ -26,7 +26,7 @@ const EVENT_EMITTER = new events.EventEmitter();
 function startEvent(
   name: string,
   data: any = null,
-  options?: EventOptions = {telemetric: false},
+  options?: EventOptions = {},
 ): number {
   if (name == null) {
     throw new Error('No event name specified!');
@@ -64,7 +64,7 @@ function forgetEvent(id: number): void {
 }
 
 function logEvent(id: number, phase: 'startEvent' | 'endEvent'): void {
-  const event = EVENT_INDEX[id];
+  const event = getEvent(id);
   EVENT_EMITTER.emit(phase, id);
 
   if (!ENABLED) {
@@ -80,20 +80,24 @@ function logEvent(id: number, phase: 'startEvent' | 'endEvent'): void {
 
   const logTimeStamp = new Date().toLocaleString();
   const dataString = data ? ': ' + JSON.stringify(data) : '';
-  const {telemetric} = options;
+  const {telemetric, silent} = options;
 
   switch (phase) {
     case 'startEvent':
-      // eslint-disable-next-line no-console-disallow
-      console.log(chalk.dim(`[${logTimeStamp}] <START> ${name}${dataString}`));
+      if (!silent) {
+        // eslint-disable-next-line no-console-disallow
+        console.log(chalk.dim(`[${logTimeStamp}] <START> ${name}${dataString}`));
+      }
       break;
 
     case 'endEvent':
-      // eslint-disable-next-line no-console-disallow
-      console.log(
-        chalk.dim(`[${logTimeStamp}] <END>   ${name}${dataString} `) +
-        (telemetric ? chalk.reset.cyan(`(${+durationMs}ms)`) : chalk.dim(`(${+durationMs}ms)`))
-      );
+      if (!silent) {
+        // eslint-disable-next-line no-console-disallow
+        console.log(
+          chalk.dim(`[${logTimeStamp}] <END>   ${name}${dataString} `) +
+          (telemetric ? chalk.reset.cyan(`(${+durationMs}ms)`) : chalk.dim(`(${+durationMs}ms)`))
+        );
+      }
       forgetEvent(id);
       break;