scripts/style/json-fmt.py

#!/usr/bin/env python2.7
# Copyright 2018 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Script to format JSON files.

This script accepts a list of files as arguments, and for each of them attempts
to parse it as JSON, and update it in-place with a pretty-printed version. Stops
on the first error.
"""

import argparse
import json
import sys


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'file',
        type=argparse.FileType('r+'),
        nargs='+',
        help='JSON file to be pretty-printed.')
    args = parser.parse_args()
    for json_file in args.file:
        try:
            with json_file:
                data = json.load(json_file)
                json_file.seek(0)
                json_file.truncate()
                json.dump(
                    data,
                    json_file,
                    indent=4,
                    sort_keys=True,
                    separators=(',', ': '))
                json_file.write('\n')
        except:
            print("Exception encountered while processing file " + json_file.name)
            raise

if __name__ == "__main__":
    main()