Helping prevention of accidental directory exclusion when using the --export-on-exit option

[Muritavo]

Description

Adding condition to prevent the user from setting the --export-on-exit option to the CWD, inflicting in directory exclusion after stopping the emulators

Scenarios Tested

The firebase emulators:start command should fail now if the --export-on-exit is set to the CWD or parent directories

Commands tested:

• Current dir (SHOULD FAIL): firebase emulators:start --export-on-exit ./

• Current dir parent (SHOULD FAIL): firebase emulators:start --export-on-exit ../

• Implicit --export-on-exit via setting the --import flag (SHOULD FAIL): firebase emulators:start --import ./ --export-on-exit

• A sub directory (SHOULD PASS): firebase emulators:start --export-on-exit ./dump-db

• Implicit --export-on-exit sub directory (SHOULD PASS): firebase emulators:start --import ./dump-db --export-on-exit

Sample Commands

Should not allow:

firebase emulators:start --export-on-exit ./

One that should allow:

firebase emulators:start --export-on-exit ./dump-db

[yuchenshi]

Thanks for the PR! Getting someone to take a look

[yuchenshi]

Overall I think is a good stop-gap solution and I'm happy to merge this once the comments are addressed. (It would be even better though if we can find a way to export without nuking the target directory, but that is a longer term solution.)

[Muritavo]

Overall I think is a good stop-gap solution and I'm happy to merge this once the comments are addressed. (It would be even better though if we can find a way to export without nuking the target directory, but that is a longer term solution.)

Yup, I just built this PR in like 1 hour to reduce the chances for people to accidentally exclude their projects by runnning the command without prior understanding. I almost lost 2 weeks of work because of this. If someone would try with their root user folder the destruction would be massive.

If I get the time, I will try to dive into the core of firebase persistency to fix this in a definitive manner and possibly rollback this PR.

Thanks for pointing out which PR (supposedly) introduced the issue, that will save up some time :)

[yuchenshi]

Thanks again for your contribution! This PR is now merged and will be included in the next release.