How to get Jest to works with v8intrinsic "--allow-natives-syntax"?

Question

After @babel/core@^7.6.0, v8intrinsic is supported to be parsed via babel, but run it with node requires a flag --allow-natives-syntax.

We are using node --allow-natives-syntax node_modules/.bin/jest here

When using it inside a jest unit test, jest-runner is not able to recognize % which used to call v8intrinsic.

Like below:

describe('foo', () => {
  beforeEach(async () => {
    await page.goto(PATH, { waitUntil: 'load' })
  })
  test('should return bar', async () => {
    const foo = await page.evaluate(() => {
      console.log('foo');

      var args = 'testing';
      %GetOptimizationStatus(args);
      
      return foo(args);
    })
    expect(foo).toBe('bar')
  })
})

Answer 1

Are you enabling the "v8intrinsic" Babel plugin?

See here for details: https://babeljs.io/blog/2019/09/05/7.6.0#v8-intrinsic-runtime-functions-parsing-10148httpsgithubcombabelbabelpull10148

(Note that I wouldn't recommend to rely on V8 intrinsics for anything, not even tests. Especially something like %GetOptimizationStatus is an internal detail that can and will change over time. If I were in your (or your team's) place, I wouldn't want to have to debug failing tests just because a new V8 version does some internal stuff slightly differently from before. But of course that's up to you...)