Set Message{Is,Expects} response correctly in go bindings

Set Message{Is,Expects} response correctly in go bindings

We should set MessageExpectsResponse in the proxy when generating an
outgoing message and MessageIsResponse when generating the reply.

R=rogulenko@google.com

Committed: https://chromium.googlesource.com/external/mojo/+/af171018862b466573e98b89e46191dcf89f49b1

[jamesr, 2015-03-03 23:36:06]

echo.mojom has this:

interface Echo {
  EchoString(string? value) => (string? value);
};

the generated code for the proxy with this patch is:

func (p *EchoProxy) EchoString(inValue *string) (outValue *string, err error) {
	payload := &echo_EchoString_Params{
		inValue,
	}
	header := bindings.MessageHeader{
		Type: echo_EchoString_Name,
		Flags: bindings.MessageExpectsResponseFlag,
		RequestId: p.ids.Next(),
	}

and for the stub is:

func (s *echoStub) Accept(message *bindings.Message) (err error) {
	switch message.Header.Type {
	case echo_EchoString_Name:
		var request echo_EchoString_Params
		if err := message.DecodePayload(&request); err != nil {
			return fmt.Errorf("can't decode request: %v", err.Error())
		}
		var response echo_EchoString_ResponseParams
		response.outValue, err = s.impl.EchoString(request.inValue)
		if err != nil {
			return
		}
		header := bindings.MessageHeader{
			Type: echo_EchoString_Name,
			Flags: bindings.MessageIsResponseFlag,
			RequestId: message.Header.RequestId,
		}

are there automated tests I should update for this?

[jamesr, 2015-03-03 23:36:53]

On 2015/03/03 23:36:06, jamesr wrote:
> echo.mojom has this:
> 
> interface Echo {
>   EchoString(string? value) => (string? value);
> };
> 
> the generated code for the proxy with this patch is:
> 
> func (p *EchoProxy) EchoString(inValue *string) (outValue *string, err error)
{
> 	payload := &echo_EchoString_Params{
> 		inValue,
> 	}
> 	header := bindings.MessageHeader{
> 		Type: echo_EchoString_Name,
> 		Flags: bindings.MessageExpectsResponseFlag,

Without this patch this line in the proxy is

		Flags: bindings.MessageIsResponseFlag,


> 		RequestId: p.ids.Next(),
> 	}
> 
> and for the stub is:
> 
> func (s *echoStub) Accept(message *bindings.Message) (err error) {
> 	switch message.Header.Type {
> 	case echo_EchoString_Name:
> 		var request echo_EchoString_Params
> 		if err := message.DecodePayload(&request); err != nil {
> 			return fmt.Errorf("can't decode request: %v", err.Error())
> 		}
> 		var response echo_EchoString_ResponseParams
> 		response.outValue, err = s.impl.EchoString(request.inValue)
> 		if err != nil {
> 			return
> 		}
> 		header := bindings.MessageHeader{
> 			Type: echo_EchoString_Name,
> 			Flags: bindings.MessageIsResponseFlag,

this line is the same (which is correct)

> 			RequestId: message.Header.RequestId,
> 		}
> 
> are there automated tests I should update for this?

[rogulenko, 2015-03-04 00:21:18]

lgtm

[jamesr, 2015-03-04 00:23:14]

Committed patchset #1 (id:1) manually as
af171018862b466573e98b89e46191dcf89f49b1 (presubmit successful).