RFE: Add "bst fmt" (or similar) to rewrite .bst files to canonical format

Background

This can be useful to keep same style format in all the files in the project

Task description

This is actually done already when running bst track

Possible solutions

We have simply used this in freedesktop-sdk/freedesktop-sdk!626 (merged)

#!/usr/bin/python3

from ruamel.yaml import round_trip_load, round_trip_dump
    
import sys
    
for filename in sys.argv[1:]:
    print(filename)
    with open(filename) as f:
        content = round_trip_load(f)
    
    with open(filename, 'w') as f:
        round_trip_dump(content, f)

Acceptance Criteria

New command is available

added Enhancement label

I like how rustfmt does it:

        --check         Run in 'check' mode. Exits with 0 if input if
                        formatted correctly. Exits with 1 and prints a diff if
                        formatting is required.

This is very useful, some projects put that in their CI so that it refuses merge requests which aren't formatted correctly.

Without this option, rustfmt just rewrites the files.

For reference, terraform has something similat:

• terraform fmt: format to canonical format
• terraform verify: check syntax

This is actually done already when running bst track

Is it ? That would seem to me to be a bug, we use ruamel.yaml round tripping explicitly to ensure that we do not change any whitespace or ordering or anything besides the thing we intend to change.

I think the feature request is a good one, but if we're accidentally doing this at bst track time, that seems problematic to me; even if the format does not adhere to some yet-to-be-defined standard; bst track should not introduce diffs which are unrelated to the changes it makes.

Is it ? That would seem to me to be a bug, we use ruamel.yaml round tripping explicitly to ensure that we do not change any whitespace or ordering or anything besides the thing we intend to change.

It is! Yeah I think it should not happen when you run bst --track, but that is #470 (closed)

marked this issue as related to #487 (closed)

removed the relation with #487 (closed)

marked this issue as related to #638

mentioned in issue #638

Update on this: As pointed out at #470 (comment 97599171), bst track still changes the indentation of the bst files, so I guess we can use that to implement this?

mentioned in merge request freedesktop-sdk/freedesktop-sdk!626 (merged)

changed the description

mentioned in merge request freedesktop-sdk/freedesktop-sdk!641 (merged)

assigned to @coldtom

mentioned in merge request !955

added Urgent label

added Doing label

added Important label and removed Urgent label

changed milestone to %BuildStream_v1.4

I think we all agree that this would be a useful feature.

I am a bit concerned about the implementation in !955, and think we need a more hands on approach to ordering of the output.

For instance, I think we can all agree that the first thing which should appear in a .bst file is the kind: attribute.

The jhbuild2bst script we used when converting jhbuild modulesets (which happens to be python2 based), shows an example of how to construct a yaml dumper with ruamel.yaml and dictate the output order of keys.

Something like this should be employed to allow control on what the default order is supposed to be. Further than this, it can be desirable to also allow plugins to contribute to informing BuildStream on what the ordering should be, since plugins also play a big part in defining the format itself.