Adds CircuitBreaker#call() method

This allows the user to control the this context within the function execution for a circuit. This method behaves in many ways like Function.prototype.call(). It takes a this context as the first parameter and any optional parameters as an argument list to the function. Here is an example usage:

const context = {
  lunch: 'sushi'
};

async function getLunch (param) {
  return param
    ? Promise.resolve(param)
    : Promise.resolve(this.lunch);
}
getLunch.lunch = 'tacos';

const circuit = new CircuitBreaker(getLunch);
circuit.call()
  .then(console.log) // logs 'tacos'
  .then(_ => {
    circuit.call(context)
      .then(console.log) // logs 'sushi'
      .then(_ => {
        circuit.call(context, 'burgers')
          .then(console.log); // logs 'burgers'
      });
  });

Extract metrics and remove factory function

4.0.0 (2019-08-21)

Breaking Changes

• The factory function has been removed in favor of simply using the CircuitBreaker constructor.
• Prometheus and Hystrix metrics have been moved into their own repositories.
• We no longer keep a set of all circuits

DO NOT USE

Breaking changes were unintentionally pushed as a minor version release. Please either stick with 3.0.0 or bump to 4.0.0.

Version 3.0.0

3.0.0 (2019-07-26)

src

• Remove the Promisify function (#354) (86a6154), closes #352

BREAKING CHANGES

• Remove the Promisify function from the CircuitBreaker factory

• Node has its own built-in promisify function that can be used instead.

Active Circuit Iterator

2.3.0 (2019-07-01)

Features

• provide an Iterator of all active circuits (#344) (13616b0)

Prometheus Options and Browser Love

2.2.0 (2019-06-24)

Bug Fixes

• ensure that including dist/opossum.js works in the browser (#341) (873deb5)

Features

• add prometheusRegistry option (#332) (0056cdc)

Prometheus improvements

2.1.0 (2019-06-12)

Features

• add function to get metrics for all circuits (#328) (ff29f2e)
• Add original function parameters to the failure and timeout events (#326) (f8918c4), closes #324

Prometheus integration

2.0.0 (2019-06-05)

Build System

• use node 12 on ci/cd in addition to 8 and 10 (93f8008)

Features

• prometheus client integration (282b467)

Breaking Changes

• health-check-failed and semaphore-locked events have been changed to healthCheckFailed and semaphoreLocked respectively

Hystrix Deprecation

Hystrix is now deprecated. We will soon be doing a major version bump to 2.0.0 adding Prometheus metrics, and changing some of the event names.

Filtering Errors

1.11.0 (2019-03-14)

Features

• add errorFilter option to bypass incrementing failure stats (8018012)