Running gulp does not compile files from /assets/css to /assets/built

[konomu]

Running gulp in my cloned repo gives

AssertionError [ERR_ASSERTION]: Task function must be specified
    at Gulp.set [as _setTask] (/home/konomu/jasper2-personal/node_modules/undertaker/lib/set-task.js:10:3)
    at Gulp.task (/home/konomu/jasper2-personal/node_modules/undertaker/lib/task.js:13:8)
    at Object.<anonymous> (/home/konomu/jasper2-personal/gulpfile.js:27:6)
    at Module._compile (node:internal/modules/cjs/loader:1356:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1414:10)
    at Module.load (node:internal/modules/cjs/loader:1197:32)
    at Module._load (node:internal/modules/cjs/loader:1013:12)
    at Module.require (node:internal/modules/cjs/loader:1225:19)
    at require (node:internal/modules/helpers:177:18)
    at requireOrImport (/usr/local/lib/node_modules/gulp-cli/lib/shared/require-or-import.js:20:11) {
  generatedMessage: false,
  code: 'ERR_ASSERTION',
  actual: false,
  expected: true,
  operator: '=='
}

and css is not built from /assets/css to /assets/built. The problem seems to be a change the way gulp handles tasks itself per https://stackoverflow.com/questions/51098749/everytime-i-run-gulp-anything-i-get-a-assertion-error-task-function-must-be
but I don't know how to solve this issue on my own.

[chadhunter]

@konomu - i ran across a similar issue when trying to update the CSS. My issue was, specifically:

ReferenceError: primordials is not defined
    at fs.js:44:5

which is related to an incompatibility between Gulp 3.x and Node.js version 12 and later. Gulp 3.x relies on a package that is no longer compatible with newer versions of Node.js

To fix this and get Gulp to write the css to assets/built, I followed the 3 steps below. Hope it helps you or others out who may read this.

1. Install Gulp 4.x

npm install gulp@^4.0.0 --save-dev

2. Updated my gulpfile.js to use the new Gulp 4.x syntax:

var gulp = require('gulp');

// gulp plugins and utils
var gutil = require('gulp-util');
var livereload = require('gulp-livereload');
var postcss = require('gulp-postcss');
var sourcemaps = require('gulp-sourcemaps');
var zip = require('gulp-zip');

// postcss plugins
var autoprefixer = require('autoprefixer');
var colorFunction = require('postcss-color-function');
var cssnano = require('cssnano');
var customProperties = require('postcss-custom-properties');
var easyimport = require('postcss-easy-import');

var swallowError = function swallowError(error) {
    gutil.log(error.toString());
    gutil.beep();
    this.emit('end');
};

// Nodemon initialization with proper done callback
var nodemonServerInit = function (done) {
    livereload.listen(1234);
    done();  // Signal that the task is complete
};

// CSS task
function css() {
    var processors = [
        easyimport,
        customProperties,
        colorFunction(),
        autoprefixer(), // Removed browsers option, as autoprefixer will use the default config
        cssnano()
    ];

    return gulp.src('assets/css/*.css')
        .on('error', swallowError)
        .pipe(sourcemaps.init())
        .pipe(postcss(processors))
        .pipe(sourcemaps.write('.'))
        .pipe(gulp.dest('assets/built/'))
        .pipe(livereload());
}

// Watch task
function watch() {
    gulp.watch('assets/css/**', css);
}

// Zip task
function zipTask() {
    var targetDir = 'dist/';
    var themeName = require('./package.json').name;
    var filename = themeName + '.zip';

    return gulp.src([
        '**',
        '!node_modules', '!node_modules/**',
        '!dist', '!dist/**'
    ])
        .pipe(zip(filename))
        .pipe(gulp.dest(targetDir));
}

// Build task (runs CSS and then starts the server)
function build(done) {
    gulp.series(css, nodemonServerInit)(done); // Properly handle async task with done
}

// Default task (runs build and watch tasks)
gulp.task('default', gulp.series(build, watch));

// Export tasks to allow running them directly
exports.css = css;
exports.watch = watch;
exports.zip = zipTask;
exports.build = build;

3. Ran Gulp again

npm run gulp