def test_half_open_state_ratio(self):
ratio = 0.2
total_executions = 1000
circuit_breaker = CircuitBreaker(half_open_ratio=ratio)
circuit_breaker.half_open()
results = []
for i in range(0, total_executions):
results.append(circuit_breaker.allows_execution())
assert circuit_breaker.current_state == 'half-open'
allowed_executions = list(filter(lambda x: x is True, results))
assert len(results) == total_executions
assert len(allowed_executions) == total_executions * ratio
def test_circut_success_resets_failures_counter(self):
circuit_breaker = CircuitBreaker(maximum_failures=3)
circuit_breaker.record_failure()
circuit_breaker.record_failure()
circuit_breaker.record_success()
circuit_breaker.record_failure()
circuit_breaker.record_failure()
assert circuit_breaker.current_state == 'closed'
def test_circut_is_opened_after_failures(self):
circuit_breaker = CircuitBreaker(maximum_failures=3)
circuit_breaker.record_failure()
circuit_breaker.record_failure()
circuit_breaker.record_failure()
assert circuit_breaker.current_state == 'open'
def test_circuit_stays_open_upon_failure_after_half_opening(self, monotonic_mock):
circuit_breaker = CircuitBreaker(maximum_failures=1, reset_timeout_seconds=20)
assert circuit_breaker.allows_execution() is True
assert circuit_breaker.current_state == 'closed'
monotonic_mock.return_value = 100
circuit_breaker.record_failure()
assert circuit_breaker.allows_execution() is False
assert circuit_breaker.current_state == 'open'
monotonic_mock.return_value = 130
assert circuit_breaker.allows_execution() is True
assert circuit_breaker.current_state == 'half-open'
circuit_breaker.record_failure()
assert circuit_breaker.allows_execution() is False
assert circuit_breaker.current_state == 'open'
def test_circut_stays_closed_after_less_failures_then_limit(self):
circuit_breaker = CircuitBreaker(maximum_failures=3)
circuit_breaker.record_failure()
circuit_breaker.record_failure()
assert circuit_breaker.current_state == 'closed'
def test_open_circuit_does_not_allow_execution(self):
circuit_breaker = CircuitBreaker(maximum_failures=1)
circuit_breaker.record_failure()
assert circuit_breaker.current_state == 'open'
assert circuit_breaker.allows_execution() is False
def test_closed_circuit_allows_execution(self):
circuit_breaker = CircuitBreaker()
assert circuit_breaker.current_state == 'closed'
assert circuit_breaker.allows_execution() is True
def test_initial_state_is_closed(self):
circuit_breaker = CircuitBreaker()
assert circuit_breaker.current_state == 'closed'