A library for lazy promises. Laissez looks like a regular promise, but under the hood it has a factory method (passed via constructor) that is only evaluated the first time someone binds a handler to the promise.
Useful for creating possible things that someone might need.
var laissez = require('laissez-bird')
var wait2 = laissez(function(){
return bluebird.delay(20)
})
// ... time passes (& no one else depends on wait2) ...
console.log('going to fire in two seconds')
wait2.then(function(){
console.log('two seconds have ellapsed')
})
In addition to the normal Promises A+ implementation, Laissez-Bird promises present a .thenever method which can be used like .then except it will not trigger the underlying factory.