Quick node.js script to mirror ASCII art horizontally

mirror-ascii-art.js

var fs = require('fs');

var charsMap = [
    [ '/', '(', '>' ],
    [ '\\', ')', '<' ]
];

function run () {
    var args = parseArgs(),
        text = normalise(fs.readFileSync(args.src, 'utf8'));

    console.log(flipText(text));
}

function parseArgs () {
    var out = {
        src: process.argv[2]
    };

    if (!out.src) {
        console.error('Arguments: source_file');
        process.exit(1);
    }

    if (!fs.existsSync(out.src)) {
        console.error('Source file not fond');
        process.exit(1);
    }

    return out;
}

function flipChar (char) {
    if (charsMap[0].indexOf(char) !== -1) {
        return charsMap[1][charsMap[0].indexOf(char)];
    } else if (charsMap[1].indexOf(char) !== -1) {
        return charsMap[0][charsMap[1].indexOf(char)];
    }

    return char;
}

function getWidth (str) {
    var out = 0;

    str.split('\n').forEach(function (line) {
        out = Math.max(out, line.length);
    });

    return out;
}

function normalise (str) {
    var out = [],
        width = getWidth(str);

    str.split('\n').forEach(function (line) {
        var newLine = '';

        for (var i = 0; i < width; i += 1) {
            newLine += line[i] || ' ';
        }

        out.push(newLine);
    });

    return out.join('\n');
}

function flipText (text) {
    var out = '';

    text.split('\n').forEach(function (line) {
        for (var i = line.length - 1; i >= 0; i -= 1) {
            out += flipChar(line[i]);
        }

        out += '\n';
    });

    return out;
}

run();