Allows braces on citekey

[mapreal19]

Closes #150

[mapreal19]

@inukshuk this is what I attempted to fix #150 but is breaking other tests. This is the right direction?

[mapreal19]

Travis not running tests? Shall we move it to Github Actions?

[inukshuk]

I was thinking to only change the lexer pattern for the parser to accept braces; we shouldn't strip them off the key, because it would be unexpected for the parser to alter the contents (this would have to go into some kind of optional filter, e.g., normalize_keys or something like that, but I don't think that it's necessary)

Yes, I think we're still configured for travis-ci.org which has been suspended and moving to Github Actions would be desirable. I'll open an issue for it.

[mapreal19]

ok! I'll help with CI first

[mapreal19]

@inukshuk you can see the failing tests. Any idea of why including the braces in the regex pattern is breaking those tests?

[inukshuk]

Hm, for some reason adding the braces seems to make the key pattern match even beyond the final comma -- it's not obvious on a quick glance why that would happen. I'll have to take a closer look.

[mapreal19]

@inukshuk worth pursuing this issue?

[inukshuk]

Sure. Maybe it's just that the pattern is thrown off because the - is treated as a range delimiter because it's not at the end of the group anymore. Does it work if you escape the minus or move it back to immediately in front of the closing bracket?

[mapreal19]

I tried that but still one test that fails

[Copilot]

Pull Request Overview

This PR adds support for allowing braces in BibTeX citation keys, which expands the valid character set for cite-key parsing.

• Updates lexer regex patterns to include curly braces as valid characters in citation keys
• Refactors key parsing logic into a dedicated method for better code organization
• Adds comprehensive test coverage for the new brace support functionality

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

File	Description
lib/bibtex/lexer.rb	Updates regex patterns to allow braces in keys and refactors key parsing into separate method
test/bibtex/test_lexer.rb	Adds test for brace support and updates test syntax to modern Minitest format
test/test_bibtex.rb	Enhances existing tests with better error message validation and updated test data
Gemfile	Adds logger dependency

Comments suppressed due to low confidence (1)

test/test_bibtex.rb:119
*

        @article{foo, },

[mapreal19]

Added to fix this warning:

warning: logger was loaded from the standard library, but will no longer be part of the default gems starting from Ruby 3.5.0.

[mapreal19]

This is the test that was failing, I couldn't find a proper way of fixing. Using an alternative test case here works.

[mapreal19]

@inukshuk can you check again when having some time? I gave it another try

[inukshuk]

You can't allow braces with optional keys, otherwise for an entry like:

@article{}

It will parse the closing brace as the key.

I added the braces to the default pattern for mandatory keys, but I remain doubtful that it's a good practice to use braces in keys. I'm not sure if it's valid or if there is useful reason to define bibtex entries with only a key and nothing else, because that would also not work for exampe:

@article{myid}

Because it would also add the closing brace to the key.

So, personally, I'd be in favor of leaving the default pattern as is. Overwrite the pattern locally to support braces.

[mapreal19]

Thanks @inukshuk!