Fixed scheduler setTimeout fallback (#14358)

* Fixed scheduler setTimeout fallback
* Moved unit-test-specific setTimeout code into a new NPM package, jest-mock-scheduler.

scripts/jest/setupTests.js

@@ -56,6 +56,8 @@ if (process.env.REACT_CLASS_EQUIVALENCE_TEST) {
     toMatchRenderedOutput: JestReact.unstable_toMatchRenderedOutput,
   });
 
+  require('jest-mock-scheduler');
+
   // We have a Babel transform that inserts guards against infinite loops.
   // If a loop runs for too many iterations, we throw an error and set this
   // global variable. The global lets us detect an infinite loop even if

scripts/rollup/bundles.js

@@ -462,6 +462,15 @@ const bundles = [
     externals: ['jest-diff'],
   },
 
+  /******* Jest Scheduler (experimental) *******/
+  {
+    bundleTypes: [NODE_DEV, NODE_PROD, FB_WWW_DEV, FB_WWW_PROD],
+    moduleType: ISOMORPHIC,
+    entry: 'jest-mock-scheduler',
+    global: 'JestMockScheduler',
+    externals: ['jest-diff'],
+  },
+
   /******* ESLint Plugin for Hooks (proposal) *******/
   {
     // TODO: it's awkward to create a bundle for this