emitter-b/src/test/node_modules/testUtils.js

An enhanced EventEmitter with extra methods for detecting whether an event has any handlers or not for efficient event handler attachment.

// you define the functions up front, and when you call the return value, it passes the arguments you call it with to the functions in sequence
// returns a function that, each time its called, calls the next function in the list with the passed argument
// example:
/*
 var sequenceX = testUtils.seq(
 function(x) {
 t.ok(x === 'a')
 },
 function(x) {
 t.ok(x === 'b')
 },
 function(x) {
 t.ok(x === 'c')
 })

 var obj = {a:1,b:2,c:3}
 for(var x in obj) {
 sequenceX(x)
 }
 */
exports.seq = function (/*functions*/) {
    var n=-1
    var fns = arguments
    return function() {
        n++
        if(n>=fns.length)
            throw new Error("Unexpected call "+n+". Arguments: "+Array.prototype.slice.call(arguments))
        // else
        fns[n].apply(this,arguments)
    }
}