1  import {
 2  	Agent,
 3  	ClientRequest,
 4  	RequestOptions,
 5  	AgentCallbackCallback,
 6  	AgentCallbackPromise,
 7  	AgentCallbackReturn
 8  } from './index';
 9  
10  type LegacyCallback = (
11  	req: ClientRequest,
12  	opts: RequestOptions,
13  	fn: AgentCallbackCallback
14  ) => void;
15  
16  export default function promisify(fn: LegacyCallback): AgentCallbackPromise {
17  	return function(this: Agent, req: ClientRequest, opts: RequestOptions) {
18  		return new Promise((resolve, reject) => {
19  			fn.call(
20  				this,
21  				req,
22  				opts,
23  				(err: Error | null | undefined, rtn?: AgentCallbackReturn) => {
24  					if (err) {
25  						reject(err);
26  					} else {
27  						resolve(rtn);
28  					}
29  				}
30  			);
31  		});
32  	};
33  }