Fix: The test randomly throws exceptions related to module imports

[liuxingbaoyu]

Q	A
Fixed Issues?	The test randomly throws exceptions related to module imports
Patch: Bug Fix?	√
Major: Breaking Change?	×
Minor: New Feature?	×
Tests Added + Pass?	√
Documentation PR Link
Any Dependency Changes?	?
License	MIT

This is a Proof Of Concept and needs more discussion.
As I mentioned in #14541 (comment), this issue is best fixed by adding new features in jest-light-runner.

jest-light-runner does not isolate tests, and packages\babel-register\test breaks the node built-in environment.
Causes the remaining tests to randomly throw exceptions related to importing the module.

Maybe there are other issues in babel-register that are contributing to this result, but that doesn't matter.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/52000/

[nicolo-ribaudo]

What breaks the environment?

babel/packages/babel-register/test/cache.js

Line 51 in 1fcc571

Module._cache = oldModuleCache;

should restore everything to the state it was before running the tests.

[liuxingbaoyu]

I do not know.
It's so hard to reproduce that I can't debug it.

It's worth mentioning that after applying the patch, I ran the CI 2*50 times without exception!💐

[liuxingbaoyu]

Well I still don't understand why the exception appears and why it disappears, but now this PR is no longer needed.