Gulp tasks to update il8n json files in jhipster

il8n.js

'use strict';

var gulp = require('gulp'),
    argv = require('yargs').argv,
    tap = require('gulp-tap');

var config = require('./config');

module.exports = {
    setProperty: setProperty,
    deleteProperty: deleteProperty,
    addProperty: addProperty
}

function deleteProperty() {
    if(argv.property === undefined) {
        throw new Error("property parameter is required");
    }
    doWork(0);
}

function setProperty() {
    if(argv.property === undefined || argv.value === undefined) {
        throw new Error("property and value parameters are required");
    }
    doWork(1);
}

function addProperty() {
    if(argv.property === undefined || argv.value === undefined || argv.filename === undefined) {
        throw new Error("property, value, and filename parameters are required");
    }
    doWork(2);
}

function doWork(operation) {

    // 0 == deleting, 1 == setting, 2 == adding
    if(operation === undefined)
        operation = 0;

    var opCount = 0;

    var str = gulp.src(config.app + 'i18n/**/*.json')
        .pipe(tap(function(file) {
            var json = getObjFromJsonFile(file);
            var prop = getDescendantProp(json, argv.property);
            if(prop !== undefined || operation == 2) {
                //if language is specified use it to filter
                if(argv.language !== undefined && !checkLanguage(file, argv.language)) {
                    // console.log("skipping file not for specified language: " + file.relative);
                    return;
                }

                if(operation == 2 && !checkFilename(file, argv.filename)) {
                    // console.log("skipping unspecified file: " + file.relative);
                    return;
                }

                console.log(getOperationString(operation) + ' property value in file: ' + file.relative);
                operation ? setDescendantProp(json, argv.property, argv.value) : deleteDescendantProp(json, argv.property);
                opCount++;
                file.contents = new Buffer(JSON.stringify(json, null, 4));
            }
        }))
        .pipe(gulp.dest(config.app + 'i18n/'));

    if(!opCount) {
        switch (operation) {
            case 0:
            case 1:
                console.log('property ' + getOperationString(operation) + ' operation did not find property "' + argv.property + '" in any file');
                break;
            case 2:
                console.log('property ' + getOperationString(operation) + ' operation did not find file "' + argv.filename + '"');
                break;
        }
    }
    return str;
}

function getOperationString(operation) {
    switch (operation) {
        case 0:
            return 'deleting';
        case 1:
            return 'setting';
        case 2:
            return 'adding';
    }
}

function setDescendantProp(obj, desc, value) {
    var arr = desc.split(".");
    for(var i = 0; i <= arr.length; i++) {
        var curr = arr.shift();
        if(obj[curr] === undefined && i < arr.length)
        {
            obj[curr] = {};
        }
        obj = obj[curr];
    }
    obj[arr[0]] = value;
}

function getDescendantProp(obj, desc) {
    var arr = desc.split('.');
    while (arr.length && (obj = obj[arr.shift()]));
    return obj;
}

function deleteDescendantProp(obj, desc) {
    var arr = desc.split(".");
    while(arr.length > 1) {
        obj = obj[arr.shift()];
    }
    delete obj[arr[0]];
}

function getObjFromJsonFile(file) {
    try {
        return JSON.parse(file.contents);
    }
    catch(e) {
        return {};
    }
}

function checkLanguage(file, language) {
    if(language !== undefined) {
        var relSplit = file.relative.split('\\');
        if (relSplit.length) {
            return relSplit[0] === language;
        }
    }
    return false;
}

function checkFilename(file, filename) {
    if(filename !== undefined) {
        var relSplit = file.relative.split('\\');
        if (relSplit.length) {
            return relSplit[1] === filename;
        }
    }
    return false;
}