@sammwy/milkshake/src/bundler.js

<p align="center"> <img src="https://raw.githubusercontent.com/sammwyy/milkshake/master/docs/milkshake.png" height="64px"> <h1 align="center">MilkShake</h1> <p align="center"> <b>Automatize Tasks, Compile, concatenate and minify automaticall

const fs = require("fs");
const path = require("path");

const Watcher = require("./utils/watcher");
const { concat } = require("./preprocessors/concatenation");
const Minifiers = require("./preprocessors/minifiers.js");
const Compressors = require("./preprocessors/compressors");
const Compilers = require("./preprocessors/compilers");
const { dir } = require("console");

let watcher = new Watcher();

exports.watchAndCompile = (extension, directory, target, main, useES6, callback) => {
    if (extension == "css") {
        watchForCSS(directory, target, callback);
    }

    else if (extension == "js") {
        watchForJS(directory, target, useES6, callback);
    }

    else if (extension == "image") {
        watchForImages(directory, target, callback);
    }

    else if (extension == "sass") {
        watchForSass(directory, main, target, callback);
    }

    else if (extension == "less") {
        watchForLess(directory, main, target, callback);
    }

    else if (extension == "stylus") {
        watchForStylus(directory, main, target, callback);
    }
}

function watchForImages (directory, target, callback) {
    const handle = async (dir, file) => {
        if (!file.toLowerCase().endsWith(".png") && !file.toLowerCase().endsWith(".jpg")) {
            return;
        }

        if (directory == dir) {
            await Compressors.compressImage(directory, target);
            callback();
        }
    }

    watcher.watch(directory);
    watcher.on("*", handle);
    handle(directory, ".jpg");
}

function watchForSass (directory, main, target, callback) {
    const handle = async (dir, file) => {
        if (!file.toLowerCase().endsWith(".sass")) {
            return;
        }
        
        if (directory == dir) {
            let compiled = await Compilers.compileSass(path.join(directory, main));
            if (compiled == null) { return; }
            let minified = Minifiers.minifyCSS(compiled);
            await saveInToFile(minified, target);
            callback();
        }
    }
    
    watcher.watch(directory);
    watcher.on("*", handle);
    handle(directory, ".sass");
}

function watchForStylus (directory, main, target, callback) {
    const handle = async (dir, file) => {
        if (!file.toLowerCase().endsWith(".styl")) {
            return;
        }
        
        if (directory == dir) {
            let compiled = await Compilers.compileStylus(directory, path.join(directory, main));
            if (compiled == null) { 
                console.error("Failed to compile stylus:\n" + compiled)
                return; 
            }
            let minified = Minifiers.minifyCSS(compiled);
            await saveInToFile(minified, target);
            callback();
        }
    }
    
    watcher.watch(directory);
    watcher.on("*", handle);
    handle(directory, ".styl"); 
}

function watchForLess (directory, main, target, callback) {
    const handle = async (dir, file) => {
        if (!file.toLowerCase().endsWith(".less")) {
            return;
        }
        
        if (directory == dir) {
            let compiled = await Compilers.compileLess(directory, path.join(directory, main));
            if (compiled == null || compiled.css == null) { 
                console.error("Failed to compile less:\n" + compiled)
                return; 
            }
            let minified = Minifiers.minifyCSS(compiled.css);
            await saveInToFile(minified, target);
            callback();
        }
    }
    
    watcher.watch(directory);
    watcher.on("*", handle);
    handle(directory, ".less"); 
}

function watchForCSS (directory, target, callback) {
    const handle = async (dir, file) => {
        if (!file.toLowerCase().endsWith(".css")) {
            return;
        }
        
        if (directory == dir) {
            let results = await concat(directory);
            let minified = Minifiers.minifyCSS(results.join("\n"));
            await saveInToFile(minified, target);
            callback();
        }
    }
    
    watcher.watch(directory);
    watcher.on("*", handle);
    handle(directory, ".css");
}

function watchForJS (directory, target, useES6, callback) {
    const handle = async (dir, file) => {
        if (!file.toLowerCase().endsWith(".js")) {
            return;
        }

        if (directory == dir) {
            let results = await concat(directory);
            let minified = Minifiers.minifyJS(results.join("\n"), useES6);
            await saveInToFile(minified, target);
            callback();
        }
    }

    watcher.watch(directory);
    watcher.on("*", handle);
    handle(directory, ".js");
}

function saveInToFile (content, target) {
    return new Promise (( resolve, reject ) => {
        fs.writeFile(target, content, () => {
            resolve();
        });
    })
}