travis2sh

#!/usr/bin/python

from __future__ import print_function

import argparse
import itertools
import sys
import yaml

script_template = """
#!/bin/bash

{functions}

$1
""".lstrip()

function_template = """
{name}() {{
{lines}
}}
"""

travis_script_segments = ('before_install', 'install', 'script')

def generate_travis_sh(travis, indentation):
    functions = (
        function_template.format(
            name=segment,
            lines='\n'.join(get_script_lines(travis[segment], indentation))
        )
        for segment in travis_script_segments
    )

    script = script_template.format(functions="\n".join(functions))
    return script

def get_script_lines(lines, indentation):
    if isinstance(lines, (str, unicode)):
        lines = [lines]

    lines = itertools.chain(*[line.split('\n') for line in lines])

    return ("{}{}".format(indentation, line) for line in lines)

def main():
    parser = argparse.ArgumentParser(
        description='Convert .travis.yml to shell script')

    parser.add_argument(
        '--output', '-o', dest='outfile',
        default=sys.stdout, type=argparse.FileType('w'),
        help='output file')
    parser.add_argument(
        'infile', metavar='INPUT', nargs='?', default=sys.stdin,
        type=argparse.FileType('r'),
        help='path to .travis.yml')
    parser.add_argument(
        '--indent-str', '-i', default=' ' * 4,
        type=unicode, help='indentation string (default: 4 spaces)')

    args = parser.parse_args()

    try:
        travis = yaml.load(args.infile)
        args.outfile.write(generate_travis_sh(travis, args.indent_str))

    finally:
        args.infile.close()
        args.outfile.close()

if __name__ == '__main__':
    main()