A Enhanced lite-server tool with sass watching

lite-server-plus.js

/**

Enhanced lite-server tool with sass watching.

## What it does

0. run `lite-server`
1. watch `scss/*.scss` and compile into `style/*.css`

## How to use

0. `npm install -g lite-server node-sass`
1. `npm link node-sass` or `npm install sass.js`
2. execute this script.

 */

'use strict';

var child_process = require('child_process');
var fs = require('fs');

var isWindows = /^win/.test(process.platform);

var liteServer = child_process.spawn(isWindows ? 'lite-server.cmd' : 'lite-server');
liteServer.stdout.pipe(process.stdout);

var sassCompile = (function () {
    try {
        var sassJs = require('sass.js');
        return scssStr =>
            new Promise(resolve => {
                sassJs.compile(scssStr, result => resolve(result.text))
            })
    } catch (err) {}

    try {
        var nodeSass = require('node-sass');
        return scssStr =>
            new Promise(resolve => {
                nodeSass.render({
                    data: scssStr
                }, (err, result) => {
                    if (err) {
                        console.log(err);
                    } else
                        resolve(result.css)
                })
            })
    } catch (err) {}

    throw 'Cannot find sass compiler!';
})();

function watchSass(src, dst) {
    function nextTrig() {
        console.log('[SASS] Compile ' + src);
        fs.readFile(src, 'utf-8', (err, srcData) => {
            sassCompile(srcData).then(css => {
                console.log('[SASS] Finished ' + src);
                fs.writeFileSync(dst, css);
            })
        })
    }
    fs.watchFile(src, nextTrig);
    nextTrig();
}

fs.readdir('scss', (err, names) => {
    var tailTest = /\.s[ca]ss$/i;
    names.filter(name => tailTest.test(name))
        .forEach(name => {
            watchSass('scss/' + name, 'style/' + name.replace(tailTest, '.css'))
        })
})