Add a format command.

[philderbeast]

Please add a format command to hpack with an --inplace option to overwrite the package.yaml file.

hpack format --inplace

• When using Dhall it's more likely that you get git conflicts when rebasing/merging (yes, commas again) SOURCE: https://github.com/BlockScope/hpack-dhall/issues/3#issuecomment-418572726

If a format command was added to hpack then use of this command could help to reduce the chance of git conflicts when rebasing/merging.

Differences

I'm currently adding some real world golden tests for the executable dhall-hpack-yaml from package hpack-dhall, trying to generate output that matches hpack's package.yaml and stack's package.yaml. The kinds of differences I've seen between handwritten and generated package.yaml files are;

• Indentation

  
  dependencies:

• base >= 4.9 && < 5
• bytestring

dependencies:

• base >= 4.9 && < 5
• bytestring

  * Field order

  category: Development maintainer: Simon Hengel sol@typeful.net extra-source-files: CHANGELOG.md github: sol/hpack

maintainer: Simon Hengel sol@typeful.net github: sol/hpack category: Development extra-source-files:

• CHANGELOG.md

  * Single element lists

  dependencies: hpack

dependencies:

• hpack

  * Empty lines

  executable: source-dirs: driver dependencies: hpack main: Main.hs tests: spec:

executable: main: Main.hs source-dirs: driver dependencies:

• hpack

tests: spec:

* Version numbers

name: stack version: ! '''1.10.0'''

name: stack version: '1.10.0'

name: hpack version: 0.31.1

[sol]

Hey! Thanks for opening this issue!

I think this can be provided as a third-party executable. Please feel free to do so.

Regarding adding this to hpack itself: Unless somebody can make the case on how this benefits hpack users at large, I'm not inclined to do so.

[tfausak]

In the past I've used a separate YAML pretty printer for this and it's worked fine.

[philderbeast]

I look for fields like name and version at the head of a package.yaml file or .cabal files and expect to find exposed-modules before other-modules and library before test-suite. This is the order fields are listed in the top-level table and other tables in the hpack docs.

I have implemented a sorting of sorts for hpack field names following the hpack docs.

Can you please consider exposing a field name comparison function in hpack itself as a lesser suggestion?

[sol]

@philderbeast for your specific used case, one thing I that could be worth trying is reading package.yaml into a Value and then compare it based on that.

I'm closing this issue, but please, if you need any changes to hpacks API, please bring them up and I'm open to discuss (no promises).

[wraithm]

@tfausak, what separate yaml pretty printer do you use? We use the imported anchor features pretty extensively in our package.yaml files. This messes up every single yaml formatter I've tried.

Here's an example of an error with prettier, but this is basically what I get with any of the other formatters:

$ prettier package.yaml
package.yaml
[error] package.yaml: SyntaxError: Aliased anchor not found: defaults (5:5)
[error] > 5 | <<: *defaults
[error]     |     ^^^^^^^^^

[tfausak]

I use yq, which I think should handle that.