var wrappy = require('wrappy')
module.exports = wrappy(once)
module.exports.strict = wrappy(onceStrict)
once.proto = once(function () {
Object.defineProperty(Function.prototype, 'once', {
value: function () {
return once(this)
},
configurable: true
})
Object.defineProperty(Function.prototype, 'onceStrict', {
value: function () {
return onceStrict(this)
},
configurable: true
})
})
function once (fn) {
var f = function () {
if (f.called) return f.value
f.called = true
return f.value = fn.apply(this, arguments)
}
f.called = false
return f
}
function onceStrict (fn) {
var f = function () {
if (f.called)
throw new Error(f.onceError)
f.called = true
return f.value = fn.apply(this, arguments)
}
var name = fn.name || 'Function wrapped with `once`'
f.onceError = name + " shouldn't be called more than once"
f.called = false
return f
}
|