Create a unified diff patch, changing the version of the config files that are most commonly used in package manager

semver-patcher.py

#!/usr/bin/env python

from __future__ import print_function
import os, getopt, sys, re, difflib, io, itertools, sys, time

# Globals vars
__VERBOSE__ = False
__VERSION__ = "0.0.1"

def eprint(*args, **kwargs):
    print(*args, file=sys.stderr, **kwargs)

def verbose(*args, **kwargs):
    if __VERBOSE__:        
        eprint(time.time(), *args, **kwargs)

def gen_diff(old, new, filename):
    return difflib.unified_diff(old, new, fromfile="a/"+filename, tofile="b/"+filename)

def gen_diff_package_json(version, content):
    pattern = '("version"\s*:\s*").*(".*)'
    substitution = r"\g<1>" + version + r"\g<2>"
    content = re.sub(pattern, substitution, content, flags = re.M)
    return io.BytesIO(content)

def gen_diff_setup_py(version, content):
    pattern = '(version\s*=\s*[\'"]).*([\'"].*)'
    substitution = r"\g<1>" + version + r"\g<2>"
    content = re.sub(pattern, substitution, content, flags = re.M)
    return io.BytesIO(content)

def gen_diff_plain_text(version, content = None):
    return io.BytesIO(version)

def gen_diff_patch_strategy(version, strategy, filenames, cwd):
    output = itertools.chain()
    for filename in filenames:
            full_filename = os.path.join(os.getcwd(), filename)
            if os.path.isfile(full_filename): 
                verbose("Detected file '%s' using '%s' patch strategy" % (full_filename, strategy))
                with open(full_filename, 'r') as fd:
                    content = fd.read()
                    patch = strategy(version, content)
                    fd.seek(0)
                    contgen = gen_diff(fd.readlines(), patch.readlines(), filename)
                    output = itertools.chain(output, contgen)
                    
    return output

def gen_diff_patch(version):
    file_diff_gen_map = [ 
        gen_diff_package_json, [ "package.json" ], 
        gen_diff_setup_py, [ "setup.py" ],
        gen_diff_plain_text, [ "VERSION" ],
    ]
    output = itertools.chain()
    for idx in range(0, len(file_diff_gen_map), 2):
        patch_generator = file_diff_gen_map[idx]
        patch_filenames = file_diff_gen_map[idx + 1]
        for line in gen_diff_patch_strategy(
            version,
            file_diff_gen_map[idx],
            file_diff_gen_map[idx + 1],
            os.getcwd()
        ):
            sys.stdout.write(line)                          
    sys.stdout.write("\n")

def show_version():
    eprint("v{0} License MIT 2020".format(__VERSION__))

def usage():
    eprint("""Usage: {program} [options] <version>

Create a unified diff patch, changing the version of the config files that 
are most commonly used in package manager
    * NPM - https://docs.npmjs.com/files/package.json
    * PYPA - https://packaging.python.org/tutorials/packaging-projects/
    * Oldschool - Plaintext file called VERSION

Available options:
  -h, --help               Show usage
  -v, --verbose            Enable verbose traces
  -v, --version            Show version

Examples

    {program} 0.0.1

    echo 0.0.1 | {program}
""".format(**{
    "program": sys.argv[0]
}))

def main():
    global __VERBOSE__
    try:
        opts, args = getopt.getopt(sys.argv[1:], "hvV", ["help", "version", "verbose"])
    except getopt.GetoptError as err:
        eprint(err)
        usage(cmd)
        sys.exit(2)
    
    for opt, value in opts:
        if opt in ("-V", "--verbose"):
            __VERBOSE__ = True
            verbose("Enabled verbose mode")
        elif opt in ("-v", "--version"):
            show_version()
            sys.exit()
        elif opt in ("-h", "--help"):
            usage()
            sys.exit()
        else:
            assert False, usage()

    if not sys.stdin.isatty():
        verbose("Reading version from stdin data")
        args = sys.stdin.readline().split()

    gen_diff_patch(args[0])

if __name__== "__main__":
	main()