New Rule: title-min-length

[mrshu]

• Add a new title-min-length rule which mimics the body-min-length
  rule in its function. The default min length is set to 5 as per the
  discussion in Add title-min-length rule #138.

• Add a few tests modeled on TitleMaxLength.

Signed-off-by: mr.Shu mr@shu.io

[mrshu]

@jorisroovers thanks a ton for a very nice tool!

I took a quick try on what could the implementation of #138 look like. Please feel free to let me know if there are things that would be worth updating -- should this end up really being part of gitlint, it would be nice to mention it in docs/rules.md as well for instance.

Thanks again!

cc @tjanez

[jorisroovers]

Left some comments/suggestions inline.

Some other places that need updating:

• Enable the rule in the config:
  

  gitlint/gitlint/config.py

  Line 45 in 6a37bae

  default_rule_classes = (rules.IgnoreByTitle,

• Add the rule and config option to the default config file (used by gitlint generate-config when generating a sample .gitlint file) https://github.com/jorisroovers/gitlint/blob/master/gitlint/files/gitlint
• As per your suggestion, the docs would need updating. Specifically docs/rules.md and the .gitlint example in docs/configuration.md

[jorisroovers]

Suggested change

	# assert error on line length > 72
	# assert error on line length < 5

[jorisroovers]

This would still allow for empty commit titles. I'd expect we'd want to capture this too?

Suggested change

	if 0 < actual_length < min_length:
	if actual_length < min_length:

I think it would be good to add a test for an empty title specifically to cover this scenario

[jorisroovers]

This is awesome, thanks so much for taking the time!

Left some comments in review.

I'm currently in a bit of a gitlint hiatus - which will affect when this is released. I will do it before the end of 2020, but might be a while... Appreciate your understanding!

[mrshu]

Thanks for your response @jorisroovers !

I believe I've applied all the changes you've suggested with two notable exceptions:

1. In the docs I was not sure what gitlint version to mention. This can be easily fixed once it comes to the release.
2. I did not include TitleMinLength among the default rules for now, as there were quite a few fixtures that would need to get updated to take it into the account. If you think it's still worth doing, I'll update the fixtures as well.

I'm currently in a bit of a gitlint hiatus - which will affect when this is released. I will do it before the end of 2020, but might be a while... Appreciate your understanding!

Feel free to take as much time as would suite you -- I really do not think there is any rush here :)

Thanks again!

[jorisroovers]

Rebased this to the new main default branch. Will be fixing the conflicts and adding the missing code soonish (this weekend hopefully).

[mrshu]

Thanks @jorisroovers -- please let me know if I can be of any help in here.

[jorisroovers]

Merged! Will go out with 0.14.0, which should be soon!