gulp-hash-cachebuster/index.js

Cachebuster plugin for gulp

var through = require('through2');
var path = require('path');
var gutil = require('gulp-util');
var PluginError = gutil.PluginError;
var $ = require('cheerio');
var md5File = require('md5-file');

// Consts
const PLUGIN_NAME = 'gulp-hash-cachebuster';

var bust = function(module, fileRoot, fileContents)
{
    // Test for http(s) and don't cache bust if (assumed) served from CDN
    var protocolRegEx = /^http(s)?/;

    var scripts = $(fileContents).find('script'),
        styles = $(fileContents).find('link[rel=stylesheet]');

    var assets = [];
    for (var i = 0; i < styles.length; i++) {
        assets.push(styles[i].attribs.href);
    }

    for (var i = 0; i < scripts.length; i++) {
        assets.push(scripts[i].attribs.src);
    }

    var asset;
    var assetCleanPath;
    var assetAbsolutePath;
    var hash;
    for (var i = 0; i < assets.length; i++) {
        asset = assets[i];

        if (asset != undefined) {
            assetCleanPath = asset.replace(/(\?|&)hash=[0-9a-z]{32}/, '');
            assetAbsolutePath = fileRoot + "/" + assetCleanPath;
            if (!protocolRegEx.test(asset)) {
                try{
                    hash = md5File.sync(assetAbsolutePath)
                }catch(e){
                    hash = undefined;
                    if(e.code == "ENOENT"){
                        //gutil.log(gutil.colors.red("Asset not found: "+assetCleanPath));
                        module.emit("warning", "Asset not found: "+assetCleanPath);
                    }else
                        throw(e);
                }

                fileContents = fileContents.replace(asset, assetCleanPath + '?hash=' + hash);
            }
        }
    }

    return fileContents;
};

// Plugin level function(dealing with files)
var gulpHashCacheBuster = function(options)
{
    //if (!options) {
    //    throw new PluginError(PLUGIN_NAME, 'Missing options');
    //}

    // Creating a stream through which each file will pass
    return through.obj(function(file, enc, cb)
    {
        if (file.isNull()) {
            // return empty file
            return cb(null, file);
        }

        if (file.isBuffer()) {
            file.contents = new Buffer(bust(this, path.dirname(file.path), file.contents.toString()));
        }

        if (file.isStream()) {
            this.emit('error', new PluginError(PLUGIN_NAME, 'Streaming not supported'));
        }

        cb(null, file);
    });
}

// Exporting the plugin main function
module.exports = gulpHashCacheBuster;