Gulp 4.0: gulp-remember or gulp-cache prevent sass to compile properly (Incremental build)

Question

yesterday I've upgraded my Gulp to 4.0 in order to gain some speed while compiling styles for my project (they got big, right now on my Mac Pro 2016 I need to wait 19seconds)

After some digging I decided to add gulp-cached and gulp-remember to my build.

Here's my current gulpfile.js for the styles:

var gulp  = require('gulp'),
sass = require('gulp-sass'),
cached = require('gulp-cached'),
sourcemaps = require('gulp-sourcemaps'),
autoprefixer = require('gulp-autoprefixer'),
remember = require('gulp-remember'),
gs = gulp.series,
concat = require('gulp-concat'),
gp = gulp.parallel;

gulp.task('compile:styles', () => {
return gulp.src([

    // Grab your custom scripts
    './assets/scss/**/*.scss'

])
    .pipe(sourcemaps.init()) // Start Sourcemaps
    .pipe(cached('sass'))
    .pipe(sass())
    .pipe(autoprefixer({
        browsers: ['last 2 versions']
    }))
    .pipe(remember('sass'))
    .pipe(sourcemaps.write('.')) // Creates sourcemaps for minified styles
    .pipe(gulp.dest('./assets/css/'));
});

gulp.task('watch:styles', () => {
gulp.watch('./assets/scss/**/*.scss', gs('styles'))
    .on('change', function (event) {
        console.log("event happened:"+JSON.stringify(event));
        if (event.type === 'deleted') {
            //delete from gulp-remember cache
            remember.forget('sass', event.path);
            //delete from gulp-cached cache
            delete cache.caches['sass'][event.path];
        }
    });
 });

gulp.task('watch', gp(
'watch:styles'
));

My issue here is that my build works well on first compilation which takes about 3 seconds, later on where ever I do a change it can see in which file I made that change, and it starting to compile, but the output file does not have the changes inside.

I think I am not getting something when it comes to gulp-cached and gulp-remeber. But at the end of the file you can see a function that are supposed to clean the caches once a change was made.

Can you please take a look at my code? Maybe you will have some advice.

Cheers!

### EDIT 26.08

I have encountered the following post while looking for a solution: http://blog.reactandbethankful.com/posts/2015/05/01/building-with-gulp-4-part-4-incremental-builds/

I went with it accordingly with the following code (but the effect is same as in above example):

// Grab our gulp packages
var gulp  = require('gulp'),
sass = require('gulp-sass'),
sourcemaps = require('gulp-sourcemaps'),
autoprefixer = require('gulp-autoprefixer'),
gs = gulp.series,
gp = gulp.parallel,
cache  = require('gulp-memory-cache');

gulp.task('compile:styles', () => {
return gulp.src('./assets/scss/**/*.scss', {since: cache.lastMtime('sass')})
    .pipe(sourcemaps.init()) // Start Sourcemaps
    .pipe(sass())
    .pipe(autoprefixer({
        browsers: ['last 2 versions']
    }))
    .pipe(cache('sass'))
    .pipe(sourcemaps.write('.')) // Creates sourcemaps for minified styles
    .pipe(gulp.dest('./assets/css/'));
});

gulp.task('watch:styles', () => {
gulp.watch('./assets/scss/**/*.scss', gs('compile:styles'))
    .on('change', cache.update('sass'));
});

gulp.task('build', gs(
'compile:styles',
'watch:styles'
));

Answer 1

I have created a complete gulpfile.js here: https://gist.github.com/MkBeeCtrl/5a6a0900dba1c5d42dc7b6da211b3e95

With js files compilation included.

// Grab our gulp packages
var gulp  = require('gulp'),
sass = require('gulp-sass'),
sourcemaps = require('gulp-sourcemaps'),
autoprefixer = require('gulp-autoprefixer'),
gs = gulp.series,
gp = gulp.parallel,
cached  = require('gulp-cached'),
dependents = require('gulp-dependents');

gulp.task('compile:styles', () => {
return gulp.src('./assets/scss/**/*.scss')
    .pipe(cached('sass'))
    .pipe(dependents())
    .pipe(sourcemaps.init()) // Start Sourcemaps
    .pipe(sass())
    .pipe(autoprefixer({browsers: ['last 2 versions']}))
    .pipe(sourcemaps.write('.')) // Creates sourcemaps for minified styles
    .pipe(gulp.dest('./assets/css/'));
});

gulp.task('watch:styles', () => {
gulp.watch('./assets/scss/**/*.scss', gs('compile:styles'))
    .on('change', function (event) {
        console.log("event happened:"+JSON.stringify(event));
        if (event.type === 'deleted') {
            //delete from gulp-remember cache
            //emember.forget('sass', event.path);
            //delete from gulp-cached cache
            delete cache.caches['sass'][event.path];
        }
    });
});

gulp.task('build', gs(
'compile:styles',
'watch:styles'
));

The above solution works the way I want, so if you want to produce separate CSS files from multiple imported files, you can go with it. It's not blazing fast solution but I have managed to save about 1 second when recompiling (already saved about 15s, when I started this topic, a build lasted 19 secs): 1st compile: ~3.5s 2nd or late: ~2.4s

You dont need to concate or order here as the whole order thing happens when you import scss files into you main file.

Answer 2

Try this one. I suppose it might do what you want to achieve:

'use strict';
const gulp = require('gulp');
const path = require('path');
const cached = require('gulp-cached');
const remember = require('gulp-remember');
const sass = require('gulp-sass');
const autoprefixer = require('gulp-autoprefixer');
const sourcemaps = require('gulp-sourcemaps');
const concat = require('gulp-concat');

gulp.task('styles:compile', function() {
    return gulp.src('assets/scss/**/*.scss', {since: gulp.lastrun('styles:compile')})
        .pipe(sourcemaps.init()) 
        //.pipe(cached('sass')) - a smarter but heavier alternative to since
        .pipe(remember('sass'))
        .pipe(concat('all.sass'))
        .pipe(sass())
        .pipe(autoprefixer({ browsers: ['last 2 versions'] }))
        .pipe(sourcemaps.write()) 
        .pipe(gulp.dest('assets/css/'));
});

gulp.task('styles:watch', function() {
    var watcher = gulp.watch('assets/scss/**/*.scss', gulp.series('compile:styles'));
    watcher.on('unlink', function(filepath) {
        remember.forget('sass', path.resolve(filepath));
        //delete cached.caches.sass[path.resolve(filepath)];
    });
});

gulp.task('default', gulp.series('styles:compile', 'styles:watch'));

Install path plugin to resolve paths. Use 'unlink' event if you want to detect when a file gets deleted. since just checks dates which is faster compared to cached that reads and compares content. But cached is more reliable (for example, when you deleted and then returned the file using your IDE tools since will not work since the file will be returned again with its old date). Also check paths - I might have messed them up.