Updated gist to support React Native 0.55

rn_bug.py

#!/usr/bin/env python3

import urllib.request
import sys
import argparse
import configparser


def main(parsed_args):
    url = get_rn_url(parsed_args)

    response = urllib.request.urlopen(url)
    data = response.read()
    text = data.decode('utf-8').split("\n")
    line_and_column = parsed_args['line'].split(":")
    line_no = int(line_and_column[0])
    column = -1
    if len(line_and_column) > 1:
        column = int(line_and_column[1])
    line_min = line_no - parsed_args['rows']
    if line_min < 0:
        line_min = 0
    line_max = line_no + parsed_args['rows']
    if line_max > len(text):
        line_max = len(text)
    for i, line in enumerate(text):
        if line_min <= i <= line_max:
            if i == line_no and column >= 0:
                print((" " * (column - 1)) + "^")
                print(line)
            elif (i + 1) == line_no:
                print(">" + line)
            else:
                print(line)

        if i > line_max:
            break


def get_rn_url(parsed_args):
    base_url = parsed_args['url']
    if ":" not in base_url:
        base_url += ":" + str(parsed_args['port'])
    if "://" not in base_url:
        base_url = "http://" + base_url
    url = base_url + "/index" + ".bundle?platform=" + parsed_args['platform'] + "&dev=" + str(
        not parsed_args['prod']).lower() + "&hot=" + str(parsed_args['hot']).lower() + "&minify=" + str(parsed_args['minify']).lower()
    return url


def parse_args():
    platform = "ios"
    if sys.platform != "darwin":
        platform = "android"

    cli_args = read_cli_args(platform)

    substitute_args_from_ini(cli_args)

    return cli_args


def substitute_args_from_ini(args):
    if (args['config'] is not None):
        conf = configparser.ConfigParser()
        conf.read(args['config'])
        options = conf.options(args['config_section'])
        for opt in options:
            args[opt] = conf.get(args['config_section'], opt)


def read_cli_args(platform):
    parser = argparse.ArgumentParser(description="Finds log information about cryptic React Native errors")
    parser.add_argument("-c", "--config", help="Local .ini config file to read command line defaults (useful for loading "
                                         "certain dev environment defaults)")
    parser.add_argument("-C","--config-section", help="The section of the .ini config file to read from (useless without "
                                                 "--config param and defaults to 'default')", default="default")
    parser.add_argument("-u", "--url", help="The URL where the npm server is located", default="localhost")
    parser.add_argument("-P","--port", type=int, help="Port number of server (default 8081)", default=8081)
    parser.add_argument("line", help="Line (and column) number of the error in LLLL:CC format")
    parser.add_argument("-p", "--platform", help="Platform to target (ios or Android). Default is iOS if run on macOS, otherwise Android", default=platform)
    parser.add_argument("--prod", help="Is build made for production? (i.e. dev=false in URL)", action="store_true", default=False)
    parser.add_argument("--hot", help="Is build setup for hot reloading? (i.e. hot=true in URL)", action="store_true", default=False)
    parser.add_argument("-m", "--minify", help="Is build setup to be minified? (i.e. minify=true)", action="store_true", default=False)
    parser.add_argument("-r", "--rows", type=int, default=6)
    cli_args = parser.parse_args()
    cli_args = vars(cli_args)
    return cli_args


if __name__ == '__main__':
    args = parse_args()
    main(args)

# Check out rn_bug.py -h for more details on the parameters or just look at read_cli_args() for more info