Enable configurable indentation

[AnthonyWC]

e.g.

foo.json

{
  "test": {
    "s1": "bar",
    "s2": [
      "snowflake",
      "s3",
      "gcloud"
    ]
  }
}

yq -y . foo.json

test:
  s1: bar
  s2:
  - snowflake
  - s3
  - gcloud

When valid yaml should be:

 test:
   s1: bar
   s2:
     - snowflake
     - s3
     - gcloud

[kislyuk]

That format is valid YAML.

[AnthonyWC]

Interesting; didn't realize the spec allowed for 0 spacing. However it seems it would fail some yaml linter; is it possible to specify a default format spacing?

[kislyuk]

yq currently uses PyYAML for YAML encoding. If there is an option that can be passed to PyYAML to specify the spacing, then yes, we can make that happen. Can you take a look at the PyYAML docs and give an example of the option if it exists?

[AnthonyWC]

From here there is some suggestions https://stackoverflow.com/questions/25108581/python-yaml-dump-bad-indentation but doesn't look like a native PyYAML option exists. Also there is a bug with indentation with lists in PyYAML (yaml/pyyaml#234)

[kislyuk]

OK thanks. It looks like ruamel.yaml has that option. I'm going to take another look at switching away from PyYAML (it has a number of flaws).

[gecube]

Can we switch to https://github.com/crdoconnor/strictyaml ? Will it fix the issue or not?
I didn't make the comparison to PyYAML yet, but it looks very promising.

[kislyuk]

No. It introduces too many incompatibilities with YAML features that are in common use.

[kislyuk]

At this point I find there is no suitable replacement for PyYAML. Therefore this bug is blocked by yaml/pyyaml#234.

[jayvdb]

Previous issue regarding indentation: #29

Previous issue regarding ruamel.yaml #15 , which I have left at comment at as I think ruamel.yaml is stable now (it wasnt when the issue was closed) and is highly desirable.

[daks]

Hello, I'm facing the same problem, my YAML lists are converted from

foo:
  - bar
  - baz

to

foo:
- bar
- baz

which introduces unecessary and hard-to-review changes. I would also like the possibility of defining custom indentation.

PS: Thanks for this useful tool

[jayvdb]

I did some further analysis of available tools at adrienverge/yamllint#62 (comment) . In short, ruamel.yaml.cmd is a very useful tool to post-process yaml out of yq , to restore expected indentation.

It would be great if ruamel.yaml was used internally by yq for even better results.
ruamel.yaml is now 1.0+ , so the API is now stable.

[kislyuk]

At this point I consider staying with PyYAML to be the safest course of action. PyYAML has at least 3 orders of magnitude more usage and exposure than ruamel.yaml, and recently regained tractable maintainership. This bug remains blocked by yaml/pyyaml#234.

[kislyuk]

I have found a way to address this issue. By default, yq -y will now indent block lists by 2 spaces ( - item instead of - item). The old behavior (0 spaces, the PyYAML default) can be triggered via yq -y --indentless-lists.

Released in v2.8.0, please test.

[ghost]

@kislyuk it’s working for me