script files not loading in rev-manifest.json (gulp)

Question

I have this gulpfile.js where I'm minifying my js files the problem is that when I'm doing gulp build this task is creating the minified js files but not entering the key-value pairs in the rev-manifest.json.

gulp.task('js', function (done) {
    console.log('minifying js...');
    gulp.src('./assets/**/*.js')
        .pipe(uglify())
        .pipe(rev())
        .pipe(gulp.dest('./public/assets'))
        .pipe(rev.manifest({
            cwd: 'public',
            merge: true
        }))
        .pipe(gulp.dest('./public/assets'));
    done()
});

I have a similar task for my scss files which converts scss to CSS and then minifies it. this is working absolutely fine adding proper key-value pairs in the rev-manifest.json

gulp.task('css', function (done) {
    console.log('minifying css...');
    gulp.src('./assets/sass/**/*.scss')
        .pipe(sass())
        .pipe(cssnano())
        .pipe(gulp.dest('./assets.css'));

    gulp.src('./assets/**/*.css')
        .pipe(rev())
        .pipe(gulp.dest('./public/assets'))
        .pipe(rev.manifest({
            cwd: 'public',
            merge: true
        }))
        .pipe(gulp.dest('./public/assets'));
    done();
});

this is what rev-manifest.json looks like

See it's only adding the css files here but not js files. my rev-manifest.json is present inside public/assets/

Answer 1

I just deleted the rev-manifest.js file and build it again and it worked. Took me a day to do this. Why God Why.

Answer 2

In my case, manifests were not merging, they were getting overwritten. gulp.dest() causes the file to be overwritten. We indeed have to pass the path of the manifest as parameter before the options if we want the merge to work, here is the working code :

const gulp = require('gulp');

const sass = require('gulp-sass')(require('sass'));
const cssnano = require('gulp-cssnano');
const rev = require('gulp-rev');
const uglify = require('gulp-uglify-es').default;
const imagemin = require('gulp-imagemin');
const del = require('del');

gulp.task('css', function(done){
    console.log('minifying css...');
    gulp.src('./assets/sass/**/*.scss')
    .pipe(sass())
    .pipe(cssnano())
    .pipe(gulp.dest('./assets/'));

    return gulp.src('./assets/**/*.css')
    .pipe(rev())
    .pipe(gulp.dest('./public/assets/'))
    .pipe(rev.manifest('public/assets/rev-manifest.json', {
        base: './public/assets',
        merge: true // merge with the existing manifest (if one exists)
     }))
    .pipe(gulp.dest('./public/assets/'));
    done();
});

gulp.task('js', function (done) {
    console.log('minifying js...');
    gulp.src('./assets/**/*.js')
        .pipe(uglify())
        .pipe(rev())
        .pipe(gulp.dest('./public/assets/'))
        .pipe(rev.manifest('public/assets/rev-manifest.json', {
            base: './public/assets',
            merge: true // merge with the existing manifest (if one exists)
        }))
        .pipe(gulp.dest('./public/assets/'));
    done()
});

gulp.task('images', function(done){
    console.log('compressing images...');
    gulp.src('./assets/**/*.+(png|jpg|gif|svg|jpeg)')
    .pipe(imagemin())
    .pipe(rev())
    .pipe(gulp.dest('./public/assets/'))
    .pipe(rev.manifest('public/assets/rev-manifest.json', {
        base: './public/assets',
        merge: true // merge with the existing manifest (if one exists)
     }))
    .pipe(gulp.dest('./public/assets/'));
    done();
});


// empty the public/assets directory
gulp.task('clean:assets', function(done){
    del.sync('./public/assets');
    done();
});

gulp.task('build', gulp.series('clean:assets', 'css', 'js', 'images'), function(done){
    console.log('Building assets');
    done();
});