vergissberlin / mqtt-resource

src/validate.js

class Validate {

	url (string) {
		/* eslint no-useless-escape: 0 */
		let regex = /(mqtt|mqtts|tcp|tls|ws|wss):\/\/(\w+:{0,1}\w*)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%!\-\/]))?/
		var pattern = new RegExp(regex)
		return pattern.test(string)
	}

	sourceConfiguration (input, callback) {
		let error = null

		if (!input.source.url) {
			if (!error) {
				error = new Error('URL for MQTT broker has not been set.')
			}
		}

		if (!this.url(input.source.url)) {
			if (!error) {
				error = new Error('Your defined URL is invalid. It should start with mqtt://')
			}
		}

		let port = Number.parseInt(input.source.port)
		if (Number.isNaN(port)) {
			input.source.port = 1883
		} else {
			input.source.port = port
		}

		callback(input, error)
	}

	paramConfiguration (input, callback) {
		let error = null

		if (!input.hasOwnProperty('params')) {
			if (!error) {
				return error = new Error('The parameters are not been set.')
			}
		} else {
			if (!input.params.topic) {
				if (!error) {
					error = new Error('The parameter topic has not been set.')
				}
			}
			if (!input.params.payload) {
				if (!error) {
					error = new Error('The parameter payload has not been set.')
				}
			}

			if (![0, 1, 2].includes(input.params.qos)) {
				input.params.qos = 1
			} else {
				input.params.qos.toString()
			}
		}

		callback(input, error)
	}

There is no return statement in this branch, but you do return something in other branches. Did you maybe miss it? If you do not want to return anything, consider adding return undefined; explicitly.

}

module.exports = new Validate