X-retry NPM | npm.io

Retry callback based or async function

Example

Operation

const BusyService = {
  call_times : 0,
  getHelloAtEach3Times : function (must_be_hi, callback) {
    this.call_times++;
    
    if (this.call_times % 3 === 0) {
      return callback(null, 'hello');
    }

    let BusyError = new Error('Service is busy');
    BusyError.status = 503;

    return callback(BusyError);
  },
  asyncGetHelloAtEach3Times : async function (must_be_hi) {
    this.call_times++;
    
    if (this.call_times % 3 === 0) {
      return 'hello';
    }

    let BusyError = new Error('Service is busy');
    BusyError.status = 503;

    throw BusyError;
  }
};

Async Retry

const { asyncRetry, Timeout } = require('x-retry');

it ('should retry a async function ok after three times', async () => {
  let message = await asyncRetry({
    func      : BusyService.asyncGetHelloAtEach3Times,
    thisArg   : BusyService,
    args      : ['hi'],
    isRetry   : (error) => !(error.status >= 400 && error.status < 500),
    maxRetry  : 3,
    timeout   : Timeout({ minTimeout : 100, maxTimeout : 10000 })
  });

  assert.equal(message, 'hello');
});

Callback Retry

const { callbackRetry, Timeout } = require('x-retry');

it ('should retry a callback function ok after three times', (done) => {
  callbackRetry({
    func      : BusyService.getHelloAtEach3Times,
    thisArg   : BusyService,
    args      : ['hi'],
    isRetry   : (error) => !(error.status >= 400 && error.status < 500),
    maxRetry  : 3,
    timeout   : Timeout({ minTimeout : 100, maxTimeout : 10000 }),
    callback  : (err, message) => (!err && message === 'hello') ? done() : done(err) 
  });
});

See more cases in test file

Functions

asyncRetry(options) ⇒ Promise.<any>

Retry a async function

Kind: function
Returns: Promise.<any> - result of async func
Throws:

ERR_REACHED_MAX_RETRY
ERR_CANNOT_RETRY when not reached max retry but isRetry() return false.

Param	Type	Default	Description
options	object
options.func	function		async function to retry
options.thisArg	object		this pointer apply to function
options.args	Array.<any>		arguments of function
options.isRetry	function		(error) => boolean
options.maxRetry	number	3	max retry times
options.timeout	number \| function		delay between retry operation, default is generated by Timeout. if is function, must match interface : (retry_count, maxRetry, logs) => number
options.activity	string		what is this activity name ? default is func.name
options.actor	string		who do this activity ? default is thisArg.name

callbackRetry(options) ⇒ void

Retry an callback based function

Kind: function
Errors: :

ERR_REACHED_MAX_RETRY
ERR_CANNOT_RETRY when not reached max retry but isRetry() return false.

Param	Type	Default	Description
options	object
options.func	function		callback based function to retry
options.thisArg	object		this pointer apply to function
options.args	Array.<any>		arguments of function
options.callback	function		callback of function
options.isRetry	function		(error) => boolean
options.maxRetry	number	3	max retry times
options.timeout	number \| function	200	delay between retry operation, , default is generated by Timeout. if is function, must match interface : (retry_count, maxRetry, logs) => number
options.activity	string		what is this activity name ? default is func.name
options.actor	string		who do this activity ? default is thisArg.name