promise-with-retry

promise-with-retry

Easily retry operations with any retry strategy you want.

Support async functions or functions returned Promise.

Intall

npm install promise-with-retry --save

Usage

const RetryOp = require('promise-with-retry').default;

function promiseOperation(...args) {
    return new Promise((resolve: any, reject: any) => {
        // ...
    });
}

async function asyncOperation(...args) {
    // ...
}

let myOp = RetryOp.buildOperation(promiseOperation);
// or async function:
// let myOp = RetryOp.buildOperation(asyncOperation);

let myRetry = new RetryOp(myAsyncOp(500), (retryOptions) => {
    if (retryOptions.returns.error) {
        // retry after 5000ms
        return 5000; 
    }
    // finish
    return;
});

Events

op_resolve

op is resolved

myRetry.on('op_resolve', (retryOptions, data) => {
});

• data: value op resolved

op_reject

op is rejected

myRetry.on('op_reject', (retryOptions, error) => {
});

• error: error op rejected

retry

event before op is executed

myRetry.on('retry', (retryOptions) => {
});

finish

op has stop retry

myRetry.on('finish', (retryOptions) => {
});

API

RetryOp.buildOperation(fn)

• fn: async function or function returned Promise

new RetryOp(op, retryStrategy)

• op: value returned by RetryOp.buildOperation(fn)
• retryStrategy: (retryOptions) => {} return a number (ms) as timeout, the retry will happen exactly after that time in milliseconds. if return is not number, will not retry.

retryOptions:

• startTime: number, ms
• totalRetryCount: number
• returns: return of op:
  • error: error op rejected
  • data: value op resolved

Example

typescript example:

import RetryOp from 'promise-with-retry';

async function asyncOperation(ms: number) {
    // ...
}

let myAsyncOp = RetryOp.buildOperation(asyncOperation);
let myRetry = new RetryOp(myAsyncOp(500), (retryOptions) => {
    if (retryOptions.totalRetryCount < 3) {
        // will retry after 500ms
        return 500;
    }
    // stop retry
    return;
});

myRetry.on('finish', (retryOptions) => {
});

Test

npm tet