fix: ignore empty IDs

[joscha]

On empty IDs the selector generator would die with an exception, because document.querySelectorAll('#') is not valid.
I thought about adding a specific check for empty IDs, however there might be more edge cases I am not aware, so I just check for a thrown exception.

This PR adds a fix and a test that fails without the fix.

[moorage]

+1

[joscha]

@fczbkk any chance to get this merged and released?

[fczbkk]

@joscha Sorry for the delay. I was busy and this slipped my mind.

When I started to fiddle with it, I found some more cases that need to be checked. So I did a bigger rewrite of ID validation mechanism. It should now correctly check not only for an empty ID, but also for ID that contains whitespace, except when sanitized ID should contain whitespace (e.g. when it contains a colon that needs to be escaped with a sequence containing a space).

Version v1.0.2 should fix all these cases.

Thank you.

[joscha]

@fczbkk cool! shall I rebase that branch then so we at least add the test?

[joscha]

ah, just saw you added that case.

[joscha]

@fczbkk could you plublish 1.0.2 to npm please?

[fczbkk]

@joscha Thanks for reminding me. Published: https://www.npmjs.com/package/css-selector-generator