yaml top document separator removed

[rockandska]

Describe the bug

When editing Yaml files with --- at its top, those hyphens are removed

Version of yq: 4.9.6
Operating system: linux
Installed via: docker

Command

$ cat << EOF > /tmp/test.yml
---
test: test
EOF
$ docker run --rm -v "/tmp":/workdir mikefarah/yq -i eval '.test = 1' test.yml

Actual behavior

$ cat /tmp/test.yml
test: 1

Expected behavior

$ cat /tmp/test.yml
---
test: 1

[mikefarah]

Yep - this is a known formatting issue with the underlying go-yaml parser.

Note that this only affects the readability of the document

[rockandska]

Note that this only affects the readability of the document

and raise an error with yamlint

[mikefarah]

Oh that's interesting - I'm not aware of it being recommended in the yaml spec shrug.

It might be worth raising the issue in go-yaml.

[ikorchynskyi]

A kind of an ugly workaround, if you really need it:

$ cat sample.yml
---
type: shelter
pets:
  - a: cat
  - b: dog

$ yq e '.' sample.yml
type: shelter
pets:
  - a: cat
  - b: dog

$ yq e '["---",.][]' sample.yml
---
type: shelter
pets:
  - a: cat
  - b: dog

[mikefarah]

Well that's unexpected...I'm not sure how that works! Gotta look into that.

[mikefarah]

Oh I see now - nice trick

[mikefarah]

I'm going to fix this up in the next release

[mikefarah]

I've put a fix in yq to check and persist the top document separator in 4.10.0 :)