utils.js

const DEFAULT_HOSTNAME = '127.0.0.1'
const DEFAULT_PORT = 4444

/**
 * helper to detect the Selenium backend according to given capabilities
 */
export function detectBackend (options = {}) {
    const { port, hostname, user, key } = options

    /**
     * browserstack
     * e.g. zHcv9sZ39ip8ZPsxBVJ2
     */
    if (typeof user === 'string' && key.length === 20) {
        return {
            hostname: 'hub.browserstack.com',
            port: 80
        }
    }

    /**
     * testingbot
     * e.g. ec337d7b677720a4dde7bd72be0bfc67
     */
    if (typeof user === 'string' && key.length === 32) {
        return {
            hostname: 'hub.testingbot.com',
            port: 80
        }
    }

    /**
     * Sauce Labs
     * e.g. 50aa152c-1932-B2f0-9707-18z46q2n1mb0
     */
    if (typeof user === 'string' && key.length === 36) {
        return {
            protocol: 'https',
            hostname: 'ondemand.saucelabs.com',
            port: 443
        }
    }

    /**
     * no cloud provider detected, fallback to local browser driver
     */
    return {
        hostname: hostname || DEFAULT_HOSTNAME,
        port: port || DEFAULT_PORT
    }
}

/**
 * initialise WebdriverIO compliant plugins
 */
export function initialisePlugin (name, type) {
    /**
     * don't populate scoped package names
     */
    const pkgName = name[0] === '@' ? name : `wdio-${name.toLowerCase()}-${type}`

    try {
        return require(pkgName)
    } catch (e) {
        if (!e.message.match(`Cannot find module '${pkgName}'`)) {
            throw new Error(`Couldn't initialise "${name}" ${type}.\n${e.stack}`)
        }

        throw new Error(
            `Couldn't find plugin "${pkgName}". You need to install it ` +
            `with \`$ npm install ${pkgName}\`!\n${e.stack}`
        )
    }
}

export function validateConfig (defaults, options) {
    const params = {}

    for (const [name, expectedOption] of Object.entries(defaults)) {
        /**
         * check if options is given
         */
        if (typeof options[name] === 'undefined' && !expectedOption.default && expectedOption.required) {
            throw new Error(`Required option "${name}" is missing`)
        }

        if (typeof options[name] === 'undefined' && expectedOption.default) {
            params[name] = expectedOption.default
        }

        if (typeof options[name] !== 'undefined') {
            if (typeof expectedOption.type === 'string' && typeof options[name] !== expectedOption.type) {
                throw new Error(`Expected option "${name}" to be type of ${expectedOption.type} but was ${typeof options[name]}`)
            }

            if (typeof expectedOption.type === 'function') {
                try {
                    expectedOption.type(options[name])
                } catch (e) {
                    throw new Error(`Type check for option "${name}" failed: ${e.message}`)
                }
            }

            if (expectedOption.match && !options[name].match(expectedOption.match)) {
                throw new Error(`Option "${name}" doesn't match expected values: ${expectedOption.match}`)
            }

            params[name] = options[name]
        }
    }

    return params
}