public void Should_call_onreset_when_manually_resetting_circuit()
{
int onBreakCalled = 0;
int onResetCalled = 0;
Action <Exception, TimeSpan> onBreak = (_, __) => { onBreakCalled++; };
Action onReset = () => { onResetCalled++; };
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak, onBreak, onReset);
onBreakCalled.Should().Be(0);
breaker.Isolate();
onBreakCalled.Should().Be(1);
breaker.CircuitState.Should().Be(CircuitState.Isolated);
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true)))
.ShouldThrow <IsolatedCircuitException>();
onResetCalled.Should().Be(0);
breaker.Reset();
onResetCalled.Should().Be(1);
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true))).ShouldNotThrow();
}
public void Should_halfopen_circuit_after_the_specified_duration_has_passed()
{
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
// 2 exception raised, circuit is now open
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
SystemClock.UtcNow = () => time.Add(durationOfBreak);
// duration has passed, circuit now half open
breaker.CircuitState.Should().Be(CircuitState.HalfOpen);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
}
public void Should_call_onbreak_when_breaking_circuit_first_time_but_not_for_subsequent_calls_through_open_circuit()
{
int onBreakCalled = 0;
Action <Exception, TimeSpan> onBreak = (_, __) => { onBreakCalled++; };
Action onReset = () => { };
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1), onBreak, onReset);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
onBreakCalled.Should().Be(0);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
onBreakCalled.Should().Be(1);
// call through circuit when already broken - should not retrigger onBreak
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
onBreakCalled.Should().Be(1);
}
public void Should_be_able_to_reset_automatically_opened_circuit_without_specified_duration_passing()
{
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
// 2 exception raised, circuit is now open
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
// reset circuit, with no time having passed
breaker.Reset();
SystemClock.UtcNow().Should().Be(time);
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true))).ShouldNotThrow();
}
public void Should_call_onreset_with_the_passed_context()
{
IDictionary <string, object> contextData = null;
Action <Exception, TimeSpan, Context> onBreak = (_, __, ___) => { };
Action <Context> onReset = context => { contextData = context; };
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak, onBreak, onReset);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
SystemClock.UtcNow = () => time.Add(durationOfBreak);
breaker.CircuitState.Should().Be(CircuitState.HalfOpen);
// first call after duration should invoke onReset, with context
breaker.ExecuteAsync(() => Task.FromResult(true), new { key1 = "value1", key2 = "value2" }.AsDictionary());
contextData.Should()
.ContainKeys("key1", "key2").And
.ContainValues("value1", "value2");
}
public void Should_report_cancellation_during_faulting_action_execution_when_user_delegate_does_not_observe_cancellationtoken()
{
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = cancellationTokenSource.Token;
int attemptsInvoked = 0;
Action onExecute = () => attemptsInvoked++;
Scenario scenario = new Scenario
{
NumberOfTimesToRaiseException = 1,
AttemptDuringWhichToCancel = 1,
ActionObservesCancellation = false
};
breaker.Awaiting(x => x.RaiseExceptionAndOrCancellationAsync <DivideByZeroException>(scenario, cancellationTokenSource, onExecute))
.ShouldThrow <TaskCanceledException>()
.And.CancellationToken.Should().Be(cancellationToken);
attemptsInvoked.Should().Be(1);
}
public void Should_honour_and_report_cancellation_during_func_execution()
{
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1));
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = cancellationTokenSource.Token;
int attemptsInvoked = 0;
Action onExecute = () => attemptsInvoked++;
bool?result = null;
Scenario scenario = new Scenario
{
NumberOfTimesToRaiseException = 0,
AttemptDuringWhichToCancel = 1,
ActionObservesCancellation = true
};
breaker.Awaiting(async x => result = await x.RaiseExceptionAndOrCancellationAsync <DivideByZeroException, bool>(scenario, cancellationTokenSource, onExecute, true).ConfigureAwait(false))
.ShouldThrow <TaskCanceledException>().And.CancellationToken.Should().Be(cancellationToken);
result.Should().Be(null);
attemptsInvoked.Should().Be(1);
}
public void Should_not_execute_action_when_cancellationtoken_cancelled_before_execute()
{
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = cancellationTokenSource.Token;
int attemptsInvoked = 0;
Action onExecute = () => attemptsInvoked++;
Scenario scenario = new Scenario
{
NumberOfTimesToRaiseException = 0,
AttemptDuringWhichToCancel = null, // Cancellation token cancelled manually below - before any scenario execution.
};
cancellationTokenSource.Cancel();
breaker.Awaiting(x => x.RaiseExceptionAndOrCancellationAsync <DivideByZeroException>(scenario, cancellationTokenSource, onExecute))
.ShouldThrow <TaskCanceledException>()
.And.CancellationToken.Should().Be(cancellationToken);
attemptsInvoked.Should().Be(0);
}
public void Should_execute_func_returning_value_when_cancellationtoken_not_cancelled()
{
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = cancellationTokenSource.Token;
int attemptsInvoked = 0;
Action onExecute = () => attemptsInvoked++;
bool?result = null;
Scenario scenario = new Scenario
{
NumberOfTimesToRaiseException = 0,
AttemptDuringWhichToCancel = null,
};
breaker.Awaiting(async x => result = await x.RaiseExceptionAndOrCancellationAsync <DivideByZeroException, bool>(scenario, cancellationTokenSource, onExecute, true).ConfigureAwait(false))
.ShouldNotThrow();
result.Should().BeTrue();
attemptsInvoked.Should().Be(1);
}
public void Should_honour_different_cancellationtoken_captured_implicitly_by_action()
{
// Before CancellationToken support was built in to Polly, users of the library may have implicitly captured a CancellationToken and used it to cancel actions. For backwards compatibility, Polly should not confuse these with its own CancellationToken; it should distinguish TaskCanceledExceptions thrown with different CancellationTokens.
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
CancellationTokenSource policyCancellationTokenSource = new CancellationTokenSource();
CancellationToken policyCancellationToken = policyCancellationTokenSource.Token;
CancellationTokenSource implicitlyCapturedActionCancellationTokenSource = new CancellationTokenSource();
CancellationToken implicitlyCapturedActionCancellationToken = implicitlyCapturedActionCancellationTokenSource.Token;
implicitlyCapturedActionCancellationTokenSource.Cancel();
int attemptsInvoked = 0;
breaker.Awaiting(x => x.ExecuteAsync(async ct =>
{
attemptsInvoked++;
await Task.FromResult(true);
implicitlyCapturedActionCancellationToken.ThrowIfCancellationRequested();
}, policyCancellationToken))
.ShouldThrow <TaskCanceledException>()
.And.CancellationToken.Should().Be(implicitlyCapturedActionCancellationToken);
attemptsInvoked.Should().Be(1);
}
public void Should_call_onhalfopen_when_automatically_transitioning_to_halfopen_due_to_subsequent_execution()
{
int onBreakCalled = 0;
int onResetCalled = 0;
int onHalfOpenCalled = 0;
Action <Exception, TimeSpan> onBreak = (_, __) => { onBreakCalled++; };
Action onReset = () => { onResetCalled++; };
Action onHalfOpen = () => { onHalfOpenCalled++; };
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak, onBreak, onReset, onHalfOpen);
onBreakCalled.Should().Be(0);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
onBreakCalled.Should().Be(0);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
onBreakCalled.Should().Be(1);
// 2 exception raised, circuit is now open
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
onBreakCalled.Should().Be(1);
SystemClock.UtcNow = () => time.Add(durationOfBreak);
// duration has passed, circuit now half open
onHalfOpenCalled.Should().Be(0); // not yet transitioned to half-open, because we have not queried state
// first call after duration is successful, so circuit should reset
breaker.ExecuteAsync(() => Task.FromResult(true));
onHalfOpenCalled.Should().Be(1);
breaker.CircuitState.Should().Be(CircuitState.Closed);
onResetCalled.Should().Be(1);
}
public void Should_not_open_circuit_if_exception_raised_is_not_the_specified_exception()
{
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1));
breaker.Awaiting(x => x.RaiseExceptionAsync <ArgumentNullException>())
.ShouldThrow <ArgumentNullException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <ArgumentNullException>())
.ShouldThrow <ArgumentNullException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <ArgumentNullException>())
.ShouldThrow <ArgumentNullException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
}
public void Should_be_able_to_handle_a_duration_of_timespan_maxvalue()
{
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(1, TimeSpan.MaxValue);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
}
public void Should_open_circuit_with_the_last_raised_exception_after_specified_number_of_specified_exception_have_been_raised()
{
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1));
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>()
.WithMessage("The circuit is now open and is not allowing calls.")
.WithInnerException <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
}
public void Context_should_be_empty_if_execute_not_called_with_any_context_data()
{
IDictionary <string, object> contextData = new { key1 = "value1", key2 = "value2" }.AsDictionary();
Action <Exception, TimeSpan, Context> onBreak = (_, __, context) => { contextData = context; };
Action <Context> onReset = _ => { };
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1), onBreak, onReset);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
contextData.Should().BeEmpty();
}
public void Should_call_onhalfopen_when_automatically_transitioning_to_halfopen_due_to_state_read()
{
int onBreakCalled = 0;
int onResetCalled = 0;
int onHalfOpenCalled = 0;
Action <Exception, TimeSpan> onBreak = (_, __) => { onBreakCalled++; };
Action onReset = () => { onResetCalled++; };
Action onHalfOpen = () => { onHalfOpenCalled++; };
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak, onBreak, onReset, onHalfOpen);
onBreakCalled.Should().Be(0);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
onBreakCalled.Should().Be(0);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
onBreakCalled.Should().Be(1);
// 2 exception raised, circuit is now open
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
onBreakCalled.Should().Be(1);
SystemClock.UtcNow = () => time.Add(durationOfBreak);
// duration has passed, circuit now half open
breaker.CircuitState.Should().Be(CircuitState.HalfOpen);
onHalfOpenCalled.Should().Be(1);
}
public void Should_call_onbreak_when_breaking_circuit_automatically()
{
bool onBreakCalled = false;
Action <Exception, TimeSpan> onBreak = (_, __) => { onBreakCalled = true; };
Action onReset = () => { };
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1), onBreak, onReset);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
onBreakCalled.Should().BeFalse();
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
onBreakCalled.Should().BeTrue();
}
public void Should_close_circuit_again_on_reset_after_manual_override()
{
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Isolate();
breaker.CircuitState.Should().Be(CircuitState.Isolated);
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true)))
.ShouldThrow <IsolatedCircuitException>();
breaker.Reset();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true))).ShouldNotThrow();
}
public void Should_create_new_context_for_each_call_to_execute()
{
string contextValue = null;
Action <Exception, TimeSpan, Context> onBreak = (_, __, context) => { contextValue = context.ContainsKey("key") ? context["key"].ToString() : null; };
Action <Context> onReset = context => { contextValue = context.ContainsKey("key") ? context["key"].ToString() : null; };
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1), onBreak, onReset);
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
// 2 exception raised, circuit is now open
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>(new { key = "original_value" }.AsDictionary()))
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
contextValue.Should().Be("original_value");
SystemClock.UtcNow = () => time.Add(durationOfBreak);
// duration has passed, circuit now half open
breaker.CircuitState.Should().Be(CircuitState.HalfOpen);
// but not yet reset
// first call after duration is successful, so circuit should reset
breaker.ExecuteAsync(() => Task.FromResult(true), new { key = "new_value" }.AsDictionary());
breaker.CircuitState.Should().Be(CircuitState.Closed);
contextValue.Should().Be("new_value");
}
public void Should_report_cancellation_when_both_open_circuit_and_cancellation()
{
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(1, TimeSpan.FromMinutes(1));
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>()
.WithMessage("The circuit is now open and is not allowing calls.")
.WithInnerException <DivideByZeroException>();
// Circuit is now broken.
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = cancellationTokenSource.Token;
int attemptsInvoked = 0;
Action onExecute = () => attemptsInvoked++;
cancellationTokenSource.Cancel();
Scenario scenario = new Scenario
{
NumberOfTimesToRaiseException = 1,
AttemptDuringWhichToCancel = null, // Cancelled manually instead - see above.
ActionObservesCancellation = false
};
breaker.Awaiting(x => x.RaiseExceptionAndOrCancellationAsync <DivideByZeroException>(scenario, cancellationTokenSource, onExecute))
.ShouldThrow <TaskCanceledException>()
.And.CancellationToken.Should().Be(cancellationToken);
attemptsInvoked.Should().Be(0);
}
public void Should_call_onbreak_with_the_passed_context()
{
IDictionary <string, object> contextData = null;
Action <Exception, TimeSpan, Context> onBreak = (_, __, context) => { contextData = context; };
Action <Context> onReset = _ => { };
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, TimeSpan.FromMinutes(1), onBreak, onReset);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>(
new { key1 = "value1", key2 = "value2" }.AsDictionary()
)).ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
contextData.Should()
.ContainKeys("key1", "key2").And
.ContainValues("value1", "value2");
}
public async Task Should_reset_circuit_after_the_specified_duration_has_passed_if_the_next_call_does_not_raise_an_exception()
{
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
// 2 exception raised, circuit is now open
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
SystemClock.UtcNow = () => time.Add(durationOfBreak);
// duration has passed, circuit now half open
breaker.CircuitState.Should().Be(CircuitState.HalfOpen);
// first call after duration is successful, so circuit should reset
await breaker.ExecuteAsync(() => Task.FromResult(0));
breaker.CircuitState.Should().Be(CircuitState.Closed);
// circuit has been reset so should once again allow 2 exceptions to be raised before breaking
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <DivideByZeroException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
breaker.Awaiting(x => x.RaiseExceptionAsync <DivideByZeroException>())
.ShouldThrow <BrokenCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Open);
}
public void Should_hold_circuit_open_despite_elapsed_time_if_manual_override_open()
{
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
breaker.CircuitState.Should().Be(CircuitState.Closed);
breaker.Isolate();
breaker.CircuitState.Should().Be(CircuitState.Isolated);
SystemClock.UtcNow = () => time.Add(durationOfBreak);
breaker.CircuitState.Should().Be(CircuitState.Isolated);
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true)))
.ShouldThrow <IsolatedCircuitException>();
}
public void Should_open_circuit_and_block_calls_if_manual_override_open()
{
var time = 1.January(2000);
SystemClock.UtcNow = () => time;
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
breaker.CircuitState.Should().Be(CircuitState.Closed);
// manually break circuit
breaker.Isolate();
breaker.CircuitState.Should().Be(CircuitState.Isolated);
// circuit manually broken: execution should be blocked; even non-exception-throwing executions should not reset circuit
breaker.Awaiting(x => x.ExecuteAsync(() => Task.FromResult(true)))
.ShouldThrow <IsolatedCircuitException>();
breaker.CircuitState.Should().Be(CircuitState.Isolated);
}
public void Should_execute_action_when_non_faulting_and_cancellationtoken_not_cancelled()
{
var durationOfBreak = TimeSpan.FromMinutes(1);
CircuitBreakerPolicy breaker = Policy
.Handle <DivideByZeroException>()
.CircuitBreakerAsync(2, durationOfBreak);
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = cancellationTokenSource.Token;
int attemptsInvoked = 0;
Action onExecute = () => attemptsInvoked++;
Scenario scenario = new Scenario
{
NumberOfTimesToRaiseException = 0,
AttemptDuringWhichToCancel = null,
};
breaker.Awaiting(x => x.RaiseExceptionAndOrCancellationAsync <DivideByZeroException>(scenario, cancellationTokenSource, onExecute))
.ShouldNotThrow();
attemptsInvoked.Should().Be(1);
}
