let fileNames = [];
let commands = [];
gulp.task('files', () => {
 gulp.src('/tests/*test.js').on('data', () => fileNames.push(data.relative))
});
function commands(){
 fileNames.forEach( (name) => commands.push(gulp.src(name).выполнениеКоманды))
};
commands();
gulp.task('run', gulp.parallel(fileNames.forEach( command => command)));