lazypipe.js

var combine = require('stream-combiner');

function lazypipe() {
	var createPipeline = function(tasks) {
		var build = function() {
				return combine.apply(null, tasks.map(function(t) {
					return t.task.apply(null, t.args);
				}));
			};
		build.pipe = function(task) {
			if(!task) {
				throw "Invalid call to lazypipe().pipe(): no task specified";
			} else if(typeof task !== 'function') {
				throw "Invalid call to lazypipe().pipe(): task is not a function";
			}
			return createPipeline(tasks.concat({
				task: task,
				args: Array.prototype.slice.call(arguments, 1)
			}));
		}
		return build;
	};
	return createPipeline([]);
}

module.exports = lazypipe;

usage_example.js

var jsHintTasks = lazypipe()
			.pipe(jshint)
			.pipe(jshint.reporter, 'jshint-stylish');

// this is OK, because lazypipes are immutable now
var jsTasks = jsHintTasks
			.pipe(gulp.dest, 'build/js');

var cssTasks = lazypipe()
			.pipe(recess, recessConfig)
			.pipe(less)
			.pipe(autoprefixer);