Node promise-circuitbreaker - Returning a value from called function

Question

I'm trying to use the promise-circuitbreaker node module. I am able to pass a parameter to the called function, however, I am unable to have the called function return a value back. Furthermore, I keep getting a timeout which I don't understand. I am obviously missing something, however I can't find any solution in the docs (http://pablolb.github.io/promise-circuitbreaker/)

I've made a very simple sample app to show my difficulties:

var CircuitBreaker = require('promise-circuitbreaker');
var TimeoutError = CircuitBreaker.TimeoutError;
var OpenCircuitError = CircuitBreaker.OpenCircuitError;


function testFcn(input, err) {
  console.log('Received param: ', input);
  //err('This is an error callback');

  return 'Value to return';
}

var cb = new CircuitBreaker(testFcn);

var circuitBreakerPromise = cb.exec('This param is passed to the function');

circuitBreakerPromise.then(function (response) {
  console.log('Never reach here:', response);
})
  .catch(TimeoutError, function (error) {
    console.log('Handle timeout here: ', error);
  })
  .catch(OpenCircuitError, function (error) {
    console.log('Handle open circuit error here');
  })
  .catch(function (error) {
    console.log('Handle any error here:', error);
  })
  .finally(function () {
    console.log('Finally always called');
    cb.stopEvents();
  });

The output I get from this is:

Received param:  This param is passed to the function
Handle timeout here:  { [TimeoutError: Timed out after 3000 ms] name: 'TimeoutError', message: 'Timed out after 3000 ms' }
Finally always called

In my case, I want a simple string to be returned. I don't want a timeout error.

If I uncomment the line //err('This is an error callback') in testFcn(), I get the following output:

Received param:  This param is passed to the function
Handle any error here: This is an error callback
Finally always called

So it appears that the 2nd parameter in the called function is for error handling.

Any help would be greatly appreciated.

Node promise-circuitbreaker - Returning a value from called function

0 Answers0