fix: disable caching when babel could not read/write cache

[JLHwung]

Q	A
Fixed Issues?	Fixes #6906, fixes #9649
Patch: Bug Fix?	Yes
Tests Added + Pass?	Added test on permission issues
Documentation PR Link
Any Dependency Changes?
License	MIT

In this PR we catch the IO error and disable caching when permission issue arises, or it the cache path resides in a readonly filesystem.

The following existsSync usage

if (fs.existsSync(file)) {
  fs.readFileSync(file)
}

is also replaced as it introduces duplicate IO operations. In general fs.existsSync should only be used

if the file won’t be used directly, for example when its existence is a signal from another process.

In the future I will open a separate PR to replace all similar usage in our codebase.

[nicolo-ribaudo]

Is it possible to add a test somehow?

[JLHwung]

Disclaimer: I have not tested on a readonly filesystem, this error code is copied from man 2 open

[EROFS] The named file resides on a read-only file system, and the file is to be modified.

[JLHwung]

@nicolo-ribaudo Added test on permission issues. On the readonly file system error, I think it is hard to reproduce on unit testing.

[nicolo-ribaudo]

[Q]: Why isn't one nextTick enough?

[JLHwung]

[A]: I thought the execution order of next tick tasks is not defined. Apparently I am wrong after reading https://nodejs.org/docs/latest/api/process.html#process_process_nexttick_callback_args, thank you for reminding me!

[nicolo-ribaudo]

@JLHwung The failing test on windows it a test of this PR.

[JLHwung]

@nicolo-ribaudo The failing test on Windows is due to the following caveats

on Windows only the write permission can be changed [by fs.chmod]

I guess that the read error could only occur when the file is owned by another user and have ACL settings excluding current user to read it. There is no isReadable mode on Windows.

As it is difficult to construct such example on Windows CI, I disable this test on Windows.