js_unuser_var_finder.py

__author__ = 'Sujayyendhiren Srinivasamurthi'
__email__ = 'sujayy1983@gmail.com'
__description__ = '''Javascript unused variable checker. 
                     Tested with a simple PAC file too.'''

import os

dupvariables = {}

def parserfunction( js_file ):
    nonvardata = ''
    js_fd = open( js_file , "r")
    js_data = [ line.strip('\n') for line in js_fd.readlines()]

    for line in js_data:
        if ('var ' in line and '[' not in line):
            variable = line.replace(' ', '').split('=')[0].split('var')[1]

            if variable not in dupvariables.keys():
                dupvariables[variable] = 1
            else:
                dupvariables[variable] += 1
        else :
            if 'var ' in line and '[' in line:
                variable = line.replace('var ','').replace(' ','').split('[')[0]
                decvariable = line.replace('var ','').replace(' ','').split('[')[1].split(']')[0]

                nonvardata+=decvariable
                if variable not in dupvariables.keys():
                    dupvariables[variable] = 1
                else:
                    dupvariables[variable] += 1
            else:
                nonvardata+= line + '\n'

    for var in dupvariables.keys():
        if var not in nonvardata:
            print "Unused variable: " + var

    js_fd.close()


if __name__ == '__main__':
    parserfunction( "test.js" )

#Test case1 - test.js file
#var abcd = 0;
#var pqrs = 1;
#var stuv = 2;
#var tv[pqrs] = 5;
#function test() {
#    pqrs = abcd;
#    return pqrs;
#}
#test()

## Similarly try different combinations