json5/tool.py

# Copyright 2014 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""A tool to parse and pretty-print JSON5.

Usage:

    $ echo '{foo:"bar"}' | python -m json5.tool
    {
        foo: 'bar',
    }
    $ echo '{foo:"bar"}' | python -m json5.tool --as-json
    {
        "foo": "bar"
    }
"""

import sys

from . import arg_parser
from . import lib
from .host import Host
from .version import VERSION


def main(argv=None, host=None):
    host = host or Host()

    parser = arg_parser.ArgumentParser(host, prog='json5', desc=__doc__)
    parser.add_argument('-c', metavar='STR', dest='cmd',
                        help='inline json5 string to read instead of '
                             'reading from a file')
    parser.add_argument('--as-json', dest='as_json', action='store_const',
                        const=True, default=False,
                        help='output as JSON '
                             '(same as --quote-keys --no-trailing-commas)')
    parser.add_argument('--indent', dest='indent', default=4,
                        help='amount to indent each line '
                             '(default is 4 spaces)')
    parser.add_argument('--quote-keys', action='store_true', default=False,
                        help='quote all object keys')
    parser.add_argument('--no-quote-keys', action='store_false',
                        dest='quote_keys',
                        help="don't quote object keys that are identifiers"
                             " (this is the default)")
    parser.add_argument('--trailing-commas', action='store_true',
                        default=True,
                        help='add commas after the last item in multi-line '
                             'objects and arrays (this is the default)')
    parser.add_argument('--no-trailing-commas', dest='trailing_commas',
                        action='store_false',
                        help='do not add commas after the last item in '
                             'multi-line lists and objects')
    parser.add_argument('file', metavar='FILE', nargs='?', default='-',
                        help='optional file to read JSON5 document from; if '
                             'not specified or "-", will read from stdin '
                             'instead')
    args = parser.parse_args(argv)

    if parser.exit_status is not None:
        return parser.exit_status

    if args.version:
        host.print_(VERSION)
        return 0

    if args.cmd:
        inp = args.cmd
    elif args.file == '-':
        inp = host.stdin.read()
    else:
        inp = host.read_text_file(args.file)

    if args.indent == 'None':
        args.indent = None
    else:
        try:
            args.indent = int(args.indent)
        except ValueError:
            pass

    if args.as_json:
        args.quote_keys = True
        args.trailing_commas = False

    obj = lib.loads(inp)
    s = lib.dumps(obj,
                  indent=args.indent,
                  quote_keys=args.quote_keys,
                  trailing_commas=args.trailing_commas)
    host.print_(s)
    return 0


if __name__ == '__main__':  # pragma: no cover
    sys.exit(main())