Regex rules with exists:0 fails

[ghostrider-05]

I want to add a rule that does not allow files to be named image\d+ and according to the documentation exists:0 can be used as:

ls:
   .png: regex:image\d+ | exists:0

However, when running with this configuration all the files that are named image\d+ are passing and files not named image\d+ are failing with:

custom_image.png failed for `.png` rules: regex:image\d+

I thought exists:0 would be applied as a seperate rule, so I removed the | and tried again with the following configuration:

ls:
   .png: regex:image\d+ exists:0

With both images failing the test:

custom_image.png failed for `.png` rules: regex:image\d+ exists:0
image214.png failed for `.png` rules: regex:image\d+ exists:0

Is this intended behaviour? In the documentation I don't see an example with exists:N and regex rules so I thought it should be possible.

Version: 2.3.0-beta.1 on NPM

[loeffel-io]

Hey @ghostrider-05, thank you for your contribution!

this is intended.

The exists rule is exclusive - exists:0 just make sure that there is no file with this extension while it can make sense to combine exists:1 or exists:1-M with other rules.

i think you need something like a not_regex rule right?

[ghostrider-05]

Ah thank you for the clarification, sorry if this has been asked before. A not_regex rule would be perfect since regex lookahead is not possible (edit: - without other libraries)

[ccoVeille]

Well I would expect to have lookahead regexp instead of not_regexp.

Would it be possible?

[ccoVeille]

this is intended.\n\nThe exists rule is exclusive - exists:0 just make sure that there is no file with this extension while it can make sense to combine exists:1 or exists:1-M with other rules.

It could be added to the documentation then 🤭😅😬

[loeffel-io]

Well I would expect to have lookahead regexp instead of not_regexp.

Would it be possible?

this is not possible because golang do not support lookaheads

[ccoVeille]

Go standard regexp doesn't support it.

But you could use another lib

https://github.com/dlclark/regexp2

[loeffel-io]

yeah but i would prefer not_regex which is pretty clear instead of a third party lib with complex lookaheads - wdyt @ccoVeille

[ccoVeille]

👍. But then the reason is what you said (and I'm fine with it) and not "go doesn't support lookahead regexp"