gulp-asset-transform/lib/schemas/streamSchema.js

A fully async Usemin-like Gulp library ===================

var joi = require('joi');

module.exports = joi.object().keys({
    pipe: joi.func().required(),
    on: joi.func().required(),
    emit: joi.func().required(),
    write: joi.func().required(),
    end: joi.func().required()
}).unknown();