Sliding Count Breaker

// Imports needed components
const { Circuit, SlidingCountBreaker } = require('mollitia');
// Creates Sliding Count Breaker Module
const slidingCountBreaker = new SlidingCountBreaker({
  name: 'my-sliding-count-breaker',
  slidingWindowSize: 6, // Failure Rate Calculation is done on the last 6 iterations
  minimumNumberOfCalls: 3, // 3 iterations are needed to start calculating the failure rate, and see if circuit should be opened or not
  failureRateThreshold: 50, // If half of the iterations or more are failing, the circuit is switched to Opened state.
  slowCallDurationThreshold: 1000, // An iteration is considered as being slow if the iteration lasts more than 1s
  slowCallRateThreshold: 80, // If at least 80% of the iterations are considered as being slow, the circuit is switched to Opened state.
  permittedNumberOfCallsInHalfOpenState: 2, // When the circuit is in Half Opened state, the circuit accepts 2 iterations in this state.
  // Once these 2 iterations are received, failure rate is calculated on these iterations.
  // If failure rate is lower than failureRateThreshold, the circuit is switched to Closed state.
  // If the failure rate is higher or equal to failureRateThreshold, the circuit is switched to Opened state.
  openStateDelay: 10000 // The circuit stays in Opened state for 10s
});
// Creates a circuit
const circuit = new Circuit({
  name: 'my-circuit',
  options: {
    modules: [ slidingCountBreaker ]
  }
});

await circuit.fn(myFunction).execute();
await circuit.fn(myFunction2).execute();
// When this 3rd iteration is received, failureRate and slowCallRate is calculated
// If the 3 iterations lasts less than 1s and are all success, then the circuit is still closed
// The circuit is opened if:
//   - at least 2 iterations failed (failure rate is 66% (2 iterations failing) or 100% (3 iterations failing), which is > 50 (failureRateThreshold))
//   - or all the iterations are slow (as slowCallRateThreshold is 80%)
await circuit.fn(myFunction3).execute();
// If
//   - circuit is still closed, then the failure rate and slow call rate threshold will be calculated when a new iteration is received
//   - circuit is opened, then the iterations are failing fast
// Here, 4th iteration received. Calculation will be done on the 4th iterations
await circuit.fn(myFunction4).execute();
// Here, 5th iteration received. Calculation will be done on the 4 iterations
await circuit.fn(myFunction5).execute();
// Here, 6th iteration received. Calculation will be done on the 6 iterations
await circuit.fn(myFunction6).execute();
// Here, number of iterations is 7. So, the 1st iteration is no longer taken into account and the calculation is done on iterations 2 to 7 
await circuit.fn(myFunction7).execute();