JSON error higlighter

test.png

valid_color_json.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""SYNOPSIS
=======
Validate a JSON given as an argument or in stdin.

If the result is correct return it indented
If an error is detected print the result on stdout (and try to place ',' if possible)
with the error highlighted according to the indication of json.loads error message
and print the error message on stdout. 

OPTION
======
	-h display this help

ERROR
=====

returns 1 on failure, 2 on help
"""


from __future__ import print_function
import sys
from json import loads, dumps
import re

from sys import argv
to_valid = None



if len(sys.argv) >= 2:
    if sys.argv[1] != '-h' and len(sys.argv) == 2:
        to_valid = sys.argv[1]
    else:
        print(__doc__)
        sys.exit(2)
else:
    to_valid = "".join(sys.stdin)

if to_valid is not None:
    output = ""
    try:
        res = loads(to_valid)
        output = dumps(res, indent=4)
        sys.stdout.write("%s\n" % output)
    except ValueError as e:
	# py2/3 gory way, mouhahahaha
        if hasattr(e, "message"):
            e = e.message

        char_bef = 0
        char_aft = -1
        to_valid+=" \n"
        mark = re.search(r'line \d+ column \d+ \(char (?P<before>\d+)( \- (?P<after>\d+))?\)', str(e))
        if mark:
            mark = mark.groupdict()
        else:
            to_valid+="\n"
            mark = dict(before = 0, after=-1)
        char_bef = int(mark["before"])
        char_aft = int(mark["after"] or (char_bef))  
        output = to_valid[:char_bef]
        FAIL = '\033[36;45;1m'
        ENDC = '\033[0m'
        output += FAIL
        delim = re.search("Expecting (.) ", str(e))
        if delim:
            output += delim.group(1)
        else:
            char_aft += 1
        
        output += to_valid[char_bef:char_aft] 
        output += ENDC 
        output += to_valid[char_aft:]
        print(output)
        
        sys.stderr.write("*" * 80 + "\n" + "ERROR DETECTED :\n"  + FAIL + str(e)+ ENDC + "\n") 
        sys.exit(1)