#magic___^_^___line when retain_line_breaks: true

[mnil]

Hello, thanks for a really neat and fast tool! Seems to work fantastic in our mono-repo.

I noticed something strange though when formatting this minimal example:

Foobar:
  baz: >
    Lorem Ipsum is simply dummy text of the printing_and_typesetting industry.

Foobaz:
  baz: "foobar"

which will get formatted into:

Foobar:
  baz: >
    Lorem Ipsum is simply dummy text of the printing_and_typesetting industry. #magic___^_^___line
Foobaz:
  baz: "foobar"

with the following config:

formatter:
  type: basic
  indent: 2
  retain_line_breaks: true

I guess there is some problem in internal/hotfix/retain_line_break.go but could not see where.

[braydonk]

Thanks for making an issue and the kind words!

This appears to be a strange edge case of scanning folded block scalars, something that's been a hassle. There's two bits of weirdness, one of which yamlfmt has a workaround for, and one that probably needs investigation in the library.

The one with a workaround is that the underlying yaml library cuts out lines for folded block scalars. This actually kind of makes sense, since that's a correct interpretation of folded block scalars from the spec, however it's really uncool for a tool like this where we want to maintain that form. For that, I've implemented a feature in the yaml library that forces re-encoding folded block scalars to retain the line breaks. I added a boolean option in the formatter config called scan_folded_as_literal to enable this. See the config docs for a bit more info there. With scan_folded_as_literal enabled, the first example in the issue remains the same after format.

The second weirdness is something I actually discovered just now while reproducing the issue. If a line in a folded block scalar ends with space characters, the encoder throws a fit and dumps the raw string value instead of producing a folded block scalar as intended. If whitespace is left at the end of a folded block scalar, you get output like this:

Foobar:
  baz: "Lorem Ipsum is simply dummy text of the printing_and_typesetting industry.
    \n#magic___^_^___line\n"
Foobaz:
  baz: "foobar"

This is a really annoying consequence, and I'll start tackling it soon.

That being said, hopefully scan_folded_as_literal will work for your issue! If it does, I will close this issue; I'll be starting the new investigation for folded block scalar lines ending with whitespace in a new issue dedicated to it.

[mnil]

You are indeed correct! With scan_folded_as_literal: true in my real example seems to give the correct output. Thanks a lot for the quick help!