describe: add ignore-rest directive

[bryceberger]

Implements #4210

Instead of a scissor line, this implements a scissor section. Everything between a pair of scissor lines is ignored. This allows it to work with #3828, as long as you put the ending line. Currently the beginning and ending lines are the same, so only one alias is required. Could easily be separated.

Implements a single scissor line, since JJ: describe lines are parsed first. Everything after a scissor line, before a JJ: describe line is ignored.

Open to other ideas on the style of the scissor lines. Additionally, the scissor template alias does not insert the "Do not modify or remove the line above." line from git --- should it? I lean softly towards no, since the user would have to seek out the alias to end up with it.

Example usage

[templates]
draft_commit_description = '''
concat(
  description,
  "\nJJ: ignore-rest\n",
  diff.git(),
)
'''

Checklist

If applicable:

• I have updated CHANGELOG.md
• I have updated the documentation (README.md, docs/, demos/)
• I have added tests to cover my changes

[bryceberger]

Updated the jjdescription tree-sitter grammar at kareigu/tree-sitter-jjdescription#2.

todo: tests, docs

[yuja]

Instead of a scissor line, this implements a scissor section. Everything between a pair of scissor lines is ignored. This allows it to work with #3828

Just fyi, #3828 should be compatible with scissors. The "JJ: describe " line should be parsed first.

(BTW, we tend to include details in commit messages than in PR description.)

[bryceberger]

Just fyi, #3828 should be compatible with scissors. The "JJ: describe " line should be parsed first.

Oh, didn't notice that. Updated to only require one line.

[bryceberger]

Paging @ilyagr and @arxanas, as you both had comments about the design of a scissor line in #4210

[martinvonz]

I think @arxanas had a good point about discoverability. Something like "JJ: ignore-after" or "JJ: ignore-rest" is a lot clearer and more searchable.

[bryceberger]

Changed to JJ: ignore-rest, and removed builtin alias as it's easy to type. Slightly less visible, but if the user wants to have a more visible marker they can easily insert it in their default template.

I do have a concern about docs. There didn't seem to be a good place to put it, so right now it's only mentioned in the changelog and "default description" config. If we keep adding similar directives (JJ: describe ..., JJ: ignore-rest, ..?), there should probably be a dedicated spot for them.

[bryceberger]

Just found the line in the default config referencing #1946, which this also provides the ability to solve.

[yuja]

Thanks!

[arxanas]

Sorry for the late reply. The overall approach and naming seems good to me. If we add more JJ: directives, we should systematically document them and consider their interactions (such as whether JJ: new-directive can appear after JJ: ignore-rest, in the same way as the implementation currently appears to allow a JJ: describe directive to follow JJ: ignore-rest).