MockChannel: Overridden methods do not declare exceptions

Issue summary:

Methods in MockChannel which override Channel interface methods do not declare the same exceptions. For example, basicAck does not declare an IOException:

Channel:

    void basicAck(long deliveryTag, boolean multiple) throws IOException;

MockChannel:

    @Override
    public void basicAck(long deliveryTag, boolean multiple) {
        getTransactionOrNode().basicAck(deliveryTag, multiple);
        metricsCollectorWrapper.basicAck(this, deliveryTag, multiple);
    }

Why it matters:

Without the declared exceptions, it is not possible to mock throwing of the checked exception. Example / use-case:

try(Channel channel = Mockito.spy(conn.createChannel())) {
  assertThat(channel).isInstanceOf(MockChannel.class);
  
  Mockito.doThrow(new IOException("ACK failed"))
    .when(channel)
    .basicAck(anyLong(), anyBoolean());
  
  // If the ACK fails (i.e. throws an IOException, my app will try 3 times.
  // This is the behaviour I want to test
  verify(channel, times(3)).basicAck(anyLong(), anyBoolean());
}

Due to the undeclared exception, this test results in an error: Checked exception is invalid for this method!

Is this a valid use case?

Is this a valid use-case, or am I using rabbitmq-mock incorrectly?

If its a valid issue, I’m happy to create a PR to fix it if that’s OK?

[ledoyen]

If you do not need it, just close 😄

[joeltoby]

@ledoyen - that sounds reasonable. I’m happy to update the sigs if that helps (and then close the issue)? If you’d prefer to leave it for now, I’ll just close.