Improve unit test robustness

Summary: When running tests locally, some are quite flaky, and there is a lot of error logging noise. This diff doesn't remove all of it, but does reduce it significantly.

Reviewed By: nikoant

Differential Revision: D20034619

fbshipit-source-id: 183f74475b644f803b2f92b1b1301f4d0f6e193a

.watchmanconfig

@@ -1 +1,3 @@
-{}
+{
+  "ignore_dirs": ["node_modules", "build", "dist"]
+}

scripts/yarn-install.js

@@ -12,6 +12,7 @@ const util = require('util');
 const glob = util.promisify(require('glob'));
 const exec = util.promisify(require('child_process').exec);
 const PACKAGES = [
+  'headless-tests',
   'static',
   'src/plugins/*',
   'src/fb/plugins/*',

src/dispatcher/__tests__/TestPlugin.js

@@ -12,3 +12,8 @@ import {FlipperPlugin} from 'flipper';
 export default class extends FlipperPlugin {
   static id = 'Static ID';
 }
+
+test('TestPlugin', () => {
+  // supress jest warning
+  expect(true).toBeTruthy();
+});

src/server.tsx

@@ -32,7 +32,10 @@ import JSDevice from './devices/JSDevice';
 import {WebsocketClientFlipperConnection} from './utils/js-client/websocketClientFlipperConnection';
 import querystring from 'querystring';
 import {IncomingMessage} from 'http';
-const ws = window.require('ws'); // Electron tries to get you to use browser's ws instead, so can't use import.
+import {isTest} from './utils/isProduction';
+// Electron tries to get you to use browser's ws instead, so can't use import.
+// @ts-ignore
+const ws = isTest() ? require('ws') : window.require('ws');
 
 type ClientInfo = {
   connection: FlipperClientConnection<any, any> | null | undefined;

src/utils/isProduction.tsx

@@ -13,6 +13,12 @@ const _isProduction = !/node_modules[\\/]electron[\\/]/.test(
   process.execPath || electron.remote.process.execPath,
 );
 
+const _isTest = !!process.env.JEST_WORKER_ID;
+
 export default function isProduction(): boolean {
   return _isProduction;
 }
+
+export function isTest(): boolean {
+  return _isTest;
+}

static/globalTestSetup.js

@@ -7,13 +7,4 @@
  * @format
  */
 
-const defaultConsoleError = console.error;
-
-console.error = function(...args) {
-  defaultConsoleError(
-    'console.error used in a test. This will be an error in the near future.',
-  );
-  defaultConsoleError(...args);
-};
-
 global.fetch = require('jest-fetch-mock');