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index.js
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index.js
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'use strict'
function signal({ onError, logExceptions } = {}) {
const handleError = onError || (logExceptions ? console.error : () => {})
let listeners = []
const api = {
push: function (listener) {
if (listeners.indexOf(listener) < 0) {
listeners.push(listener)
}
return {
pause: function () {
api.pull(listener)
},
resume: function () {
api.push(listener)
},
}
},
pull: function (listener) {
const index = listeners.indexOf(listener)
if (index > -1) {
listeners.splice(index, 1)
}
return api
},
once: function (listener) {
const handler = api.push(function (...args) {
listener(...args)
handler.pause()
})
return handler
},
trigger: function (...args) {
[...listeners].map(function (listener) {
try {
listener(...args)
} catch (e) {
handleError(e)
}
})
return api
},
triggerAsync: async function (...args) {
await Promise.all(
listeners.map(listener =>
listener(...args).catch(handleError)
)
)
return api
},
clear: function () {
listeners = []
},
}
return api
}
module.exports = signal