dispatcher.jsā¢1.29 kB
'use strict'
const EventEmitter = require('node:events')
const WrapHandler = require('../handler/wrap-handler')
const wrapInterceptor = (dispatch) => (opts, handler) => dispatch(opts, WrapHandler.wrap(handler))
class Dispatcher extends EventEmitter {
dispatch () {
throw new Error('not implemented')
}
close () {
throw new Error('not implemented')
}
destroy () {
throw new Error('not implemented')
}
compose (...args) {
// So we handle [interceptor1, interceptor2] or interceptor1, interceptor2, ...
const interceptors = Array.isArray(args[0]) ? args[0] : args
let dispatch = this.dispatch.bind(this)
for (const interceptor of interceptors) {
if (interceptor == null) {
continue
}
if (typeof interceptor !== 'function') {
throw new TypeError(`invalid interceptor, expected function received ${typeof interceptor}`)
}
dispatch = interceptor(dispatch)
dispatch = wrapInterceptor(dispatch)
if (dispatch == null || typeof dispatch !== 'function' || dispatch.length !== 2) {
throw new TypeError('invalid interceptor')
}
}
return new Proxy(this, {
get: (target, key) => key === 'dispatch' ? dispatch : target[key]
})
}
}
module.exports = Dispatcher