angular-cn/packages/zone.js/test/jest/jest-zone-patch-fake-timer.js

const exportFakeTimersToSandboxGlobal = function(jestEnv) {
  jestEnv.global.legacyFakeTimers = jestEnv.fakeTimers;
  jestEnv.global.modernFakeTimers = jestEnv.fakeTimersModern;
};

module.exports = exportFakeTimersToSandboxGlobal;