All files / hof resilient.js

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
 
 
1x
 
 
 
 
 
 
2x
 
 
 
 
2x
 
 
3x
3x
 
 
 
5x
 
1x
 
 
 
 
 
4x
4x
4x
 
 
 
 
3x
 
 
2x
 
import { VError, MultiError } from 'verror';
 
const DEFAULT_CONFIG = {
	task: 'promise resolution',
	attempts: 3,
	context: null
};
 
export default function resilient(asyncFn, config) {
	config = {
		...DEFAULT_CONFIG,
		...(config || {})
	};
 
	const maxAttempts = config.attempts;
 
	function resilientFn(...args) {
		const errors = [];
		let currentAttempts = 0;
 
		// recursive "catcher"
		function statefulCatch(err) {
			if (currentAttempts >= config.attempts) {
				// give up
				throw new VError({
					name: 'ResilientPromiseFailed',//
					cause: new MultiError(errors),
					info: { task: config.task, maxAttempts }
				}, `Resilient ${config.task} failed after ${maxAttempts}`);
			} else {
				currentAttempts += 1;
				errors.push(err);
				return asyncFn.apply(config.context, args).catch(statefulCatch);
			}
		}
 
		// kick off the chain
		return asyncFn.apply(config.context, args).catch(statefulCatch);
	}
 
	return resilientFn;
}