public void testBreakerTripsAfterTimeoutPassedWithBadCommand() throws Exception {
tripBreaker();
setTimeoutPassed();
// Now pass in a bad command
mockCommand
.expects(atLeastOnce())
.method("execute")
.will(onConsecutiveCalls(throwException(new CommandException()), returnValue(null)));
try {
underTest.doOperation(command);
} catch (Exception e) {
// ignore
}
// Circuit breaker should now be in open state
boolean exception = false;
try {
underTest.doOperation(command);
} catch (CircuitBreakerOpenException e) {
exception = true;
}
assertTrue("Circuit breaker should have tripped and so should be failing fast", exception);
}
public void testBreakerResetsAfterTimeoutPassedWithSuccessfulCommand() throws Exception {
tripBreaker();
setTimeoutPassed();
// Now pass in a working command
mockCommand.expects(atLeastOnce()).method("execute");
underTest.doOperation(command);
// Circuit breaker should now be in closed state
underTest.doOperation(command);
}
public void setUp() {
clockStub.setNow(System.currentTimeMillis());
SimpleStateFactory simpleStateFactory = new SimpleStateFactory();
simpleStateFactory.setClock(clockStub);
simpleStateFactory.setTimeoutInMillisecs(TEST_TIMEOUT_IN_MILLISECONDS);
simpleStateFactory.setFailureThreshold(FAILURE_THRESHOLD);
underTest = new SimpleCircuitBreaker();
underTest.setStateFactory(simpleStateFactory);
underTest.initialise();
mockCommand = mock(Command.class);
command = (Command) mockCommand.proxy();
}
public void testBreakerTripsAfterThresholdPassed() throws Exception {
tripBreaker();
boolean exception = false;
try {
underTest.doOperation(command);
} catch (CircuitBreakerOpenException e) {
exception = true;
}
assertTrue("Circuit breaker should have tripped and so should be failing fast", exception);
}
/** Sets the breaker into tripped state by sending commands that will fail */
private void tripBreaker() {
CommandException commandException = new CommandException();
Mock badCommand = mock(Command.class, "bad command");
badCommand.expects(atLeastOnce()).method("execute").will(throwException(commandException));
for (int i = 0; i < FAILURE_THRESHOLD; i++) {
try {
underTest.doOperation((Command) badCommand.proxy());
} catch (Exception e) {
assertEquals(commandException, e);
}
}
}
public void testDefaultOperation() throws Exception {
mockCommand.expects(once()).method("execute");
underTest.doOperation(command);
}