string_utils.js

/*jslint node: true */
"use strict";

var STRING_JOIN_CHAR = "\x00";

/**
 * Converts the argument into a string by mapping data types to a prefixed string and concatenating all fields together.
 * @param obj the value to be converted into a string
 * @returns {string} the string version of the value
 */
function getSourceString(obj) {
    var arrComponents = [];
    function extractComponents(variable) {
        if (variable === null)
            throw Error("null value in " + JSON.stringify(obj));
        switch (typeof variable) {
            case "string":
                arrComponents.push("s", variable);
                break;
            case "number":
                arrComponents.push("n", variable.toString());
                break;
            case "boolean":
                arrComponents.push("b", variable.toString());
                break;
            case "object":
                if (Array.isArray(variable)) {
                    if (variable.length === 0)
                        throw Error("empty array in " + JSON.stringify(obj));
                    arrComponents.push('[');
                    for (var i = 0; i < variable.length; i++)
                        extractComponents(variable[i]);
                    arrComponents.push(']');
                }
                else {
                    var keys = Object.keys(variable).sort();
                    if (keys.length === 0)
                        throw Error("empty object in " + JSON.stringify(obj));
                    keys.forEach(function (key) {
                        if (typeof variable[key] === "undefined")
                            throw Error("undefined at " + key + " of " + JSON.stringify(obj));
                        arrComponents.push(key);
                        extractComponents(variable[key]);
                    });
                }
                break;
            default:
                throw Error("hash: unknown type=" + (typeof variable) + " of " + variable + ", object: " + JSON.stringify(obj));
        }
    }

    extractComponents(obj);
    console.log(JSON.stringify(arrComponents));
    let re = arrComponents.join(STRING_JOIN_CHAR);
    console.log(re);
    return re;
}

exports.STRING_JOIN_CHAR = STRING_JOIN_CHAR; // for tests
exports.getSourceString = getSourceString;