electron/spec-main/events-helpers.ts

43 строки
1.2 KiB
TypeScript

/**
* @fileoverview A set of helper functions to make it easier to work
* with events in async/await manner.
*/
/**
* @param {!EventTarget} target
* @param {string} eventName
* @return {!Promise<!Event>}
*/
export const waitForEvent = (target: EventTarget, eventName: string) => {
return new Promise(resolve => {
target.addEventListener(eventName, resolve, { once: true })
})
}
/**
* @param {!EventEmitter} emitter
* @param {string} eventName
* @return {!Promise<!Array>} With Event as the first item.
*/
export const emittedOnce = (emitter: NodeJS.EventEmitter, eventName: string, trigger?: () => void) => {
return emittedNTimes(emitter, eventName, 1, trigger).then(([result]) => result)
}
export const emittedNTimes = async (emitter: NodeJS.EventEmitter, eventName: string, times: number, trigger?: () => void) => {
const events: any[][] = []
const p = new Promise<any[][]>(resolve => {
const handler = (...args: any[]) => {
events.push(args)
if (events.length === times) {
emitter.removeListener(eventName, handler)
resolve(events)
}
}
emitter.on(eventName, handler)
})
if (trigger) {
await Promise.resolve(trigger())
}
return p
}