host: string;

password?: string;

port: string;

protocol: string;

username?: string;

const url = new URL(proxyUrl);

// NOTE: The following constants are not used in the function but are defined for clarity.

// When a proxy URL is used to build the URL object, the protocol returned by procotol's property contains a `:` at

// the end so, we add the protocol constants without the `:` to avoid confusion.

const PROXY_HTTP_PROTOCOL = 'http:';

const PROXY_SOCKS_PROTOCOL = 'socks:';

switch (url.protocol) {

case PROXY_HTTP_PROTOCOL:

return new HttpsProxyAgent(url);

case PROXY_SOCKS_PROTOCOL:

return new SocksProxyAgent(url);

default:

throw new Error(`Unsupported proxy protocol: ${url.protocol}`);

}

if (typeof proxy === 'string') {

return selectProxyAgent(proxy);

}

const { host, password, port, protocol, username } = proxy;

let proxyUrl = `${protocol}://${host}:${port}`;

if (username && password) {

proxyUrl = `${protocol}://${username}:${password}@${host}:${port}`;

}

return selectProxyAgent(proxyUrl);