inject js as async (custom way)

gulpfile.js

//install
//npm i gulp-inject group-array@0.3.1
var inject = require('gulp-inject');

//inject libs js
gulp.task('inject:js', function() {
    return gulp.src('./app/*.html')
        .pipe(inject(gulp.src('./app/js/libs.min.js', { //inject more than one js in capturedbyanastasiia
            read: false //just inject no read
        }), {
            relative: true, //if true inject:js/libs.min.js, if false inject:/app/js/libs.min.js
            transform: filepath => `<script src="${filepath}" async></script>`
        }))
        .pipe(gulp.dest('./dist'));
});