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Streaming ​

A mock answers its method whatever its call type. Build checks a reply against it: a unary or client streaming method gets one message, or a status; a server or bidi streaming method gets any number of messages.

Server streaming ​

Messages(msgs...) sends the messages of the stream in turn. MessageDelay(d) waits before each message, and Status(code, msg) ends the stream with a status after its messages.

go
m.MustMock(mockgrpc.Method("Feed/Watch").
	Reply(mockgrpc.Messages(&pb.Event{Id: "1"}, &pb.Event{Id: "2"}).
		MessageDelay(100 * time.Millisecond).
		Status(codes.Unavailable, "restarting")))

The client reads the two events, then Unavailable.

Client streaming ​

A client streaming call matches once the client closed its side, on all its messages. Its request is the array of its messages: Field("$[0].key", m) reads the first, and Messages(msgs...) matches them all, in order.

go
m.MustMock(mockgrpc.Method("Upload/Send").
	Field("$[0].name", match.Equal("first")).
	Reply(mockgrpc.JSON(`{"count": 2}`)))

Echo() answers a client stream with its last message, read as the method's output type by field number.

Bidi streaming ​

A bidi call matches as it starts, on its method and metadata. Its Bidi() reply then matches each message the client sends:

MethodAnswers
On(matcher, reply)A message the matcher matches, with the reply's messages. Rules are tried in order.
Otherwise(reply)A message no rule matches.
OnEnd(reply)The end of the client's side, with the reply's messages, before the stream ends.
go
m.MustMock(mockgrpc.Method("Chat/Talk").Reply(mockgrpc.Bidi().
	On(match.Field("text", match.Equal("hi")), mockgrpc.Message(&pb.Line{Text: "hello"})).
	Otherwise(mockgrpc.JSON(`{"text": "?"}`)).
	OnEnd(mockgrpc.Message(&pb.Line{Text: "bye"}))))

The client that sends hi, then what, then closes its side reads hello, ? and bye.

Echo() answers each message of a bidi call as it comes. In a mock file, bidi takes header, trailer, on (rules of when, a matcher list of the message, and response), otherwise and on_end.

yaml
request:
  method: chat.Chat/Talk
bidi:
  on:
    - when: [field, text, [eq, hi]]
      response: {message: {text: hello}}
  otherwise: {message: {text: "?"}}
  on_end: {message: {text: bye}}

Cutting a stream ​

A Func reply that returns vlatte.ErrAbort or vlatte.ErrReset cuts the call after the messages it sent: see Cuts.