Metadata information not getting recorded for protobuf-message

[sathishathpe]

Software versions

• OS: e.g. Mac OSX 10.11.5
• Consumer Pact library: Pact go v2.0.1
• Golang Version: go1.20.5
• Golang environment: Provide output of GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/home/dev/.cache/go-build" GOENV="/home/dev/.config/go/env" GOEXE="" GOEXPERIMENT="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="linux" GOINSECURE="" GOMODCACHE="/home/dev/go/pkg/mod" GONOPROXY="github.hpe.com" GONOSUMDB="github.hpe.com" GOOS="linux" GOPATH="/home/dev/go" GOPRIVATE="github.hpe.com" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/go" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64" GOVCS="" GOVERSION="go1.20.5" GCCGO="gccgo" GOAMD64="v1" AR="ar" CC="gcc" CXX="g++" CGO_ENABLED="1" GOMOD="/home/dev/ws/pact-go/go.mod" GOWORK="" CGO_CFLAGS="-O2 -g" CGO_CPPFLAGS="" CGO_CXXFLAGS="-O2 -g" CGO_FFLAGS="-O2 -g" CGO_LDFLAGS="-O2 -g" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build1831304596=/tmp/go-build -gno-record-gcc-switches"

Expected behaviour

Adding WithMetadata() to record headers in the example documented here, does not add metadata details to the contract.

Actual behaviour

Would like to see headers added to the contract

Steps to reproduce

Run the below test

//go:build consumer
// +build consumer

package protobuf

import (
	"fmt"
	"os"
	"path/filepath"
	"testing"

	message "github.com/pact-foundation/pact-go/v2/message/v4"
	"github.com/stretchr/testify/assert"
)

var dir, _ = os.Getwd()

func TestPluginMessageConsumer(t *testing.T) {
	p, _ := message.NewAsynchronousPact(message.Config{
		Consumer: "protobufmessageconsumer",
		Provider: "protobufmessageprovider",
		PactDir:  filepath.ToSlash(fmt.Sprintf("%s/../pacts", dir)),
	})

	kafkaHeaders := map[string]string{
		"specversion": "1.0",
		"type":        "eventName",
		"source":      "sourceName",
	}

	dir, _ := os.Getwd()
	path := fmt.Sprintf("%s/../grpc/routeguide/route_guide.proto", dir)

	protoMessage := `{
		"pact:proto": "` + path + `",
		"pact:message-type": "Feature",
		"pact:content-type": "application/protobuf",

		"name": "notEmpty('Big Tree')",
		"location": {
			"latitude": "matching(number, 180)",
			"longitude": "matching(number, 200)"
		}
	}`

	err := p.AddAsynchronousMessage().
		Given("the world exists").
		ExpectsToReceive("feature message").
		WithMetadata(kafkaHeaders).
		UsingPlugin(message.PluginConfig{
			Plugin:  "protobuf",
			Version: "0.3.4",
		}).
		WithContents(protoMessage, "application/protobuf").
		ExecuteTest(t, func(m message.AsynchronousMessage) error {
			return nil
		})

	assert.NoError(t, err)
}

Relevent log files

Please ensure you set logging to DEBUG and attach any relevant log files here (or link from a gist).

[opicaud]

Hello,
I have same issue, but apparently, AsynchronousMessage is not supported for a grpc service in golang (grpc/grpc-go#246)
On my side only SynchronousMessage is ignoring Metadata as it seems that MessageV4 does not support Metadata for now:

type MessageContents struct {
	// Message Body
	Contents []byte

	// Body is the attempt to reify the message body back into a specified type
	// Not populated for synchronous  messages
	Body interface{} `json:"contents"`

	// Message metadata. Currently not populated for synchronous messages
	// Metadata Metadata `json:"metadata"`
}

Am I right ? In that case, this feature would unlock many great NFRs to test :) like mentioned below from https://grpc.io/docs/guides/metadata/#overview

gRPC metadata is useful for a variety of purposes, such as:

* Authentication: gRPC metadata can be used to send authentication credentials to the server.  
This can be used to implement different authentication schemes, such as OAuth2 or JWT using the standard HTTP Authorization header.
* Tracing: gRPC metadata can be used to send tracing information to the server. 
This can be used to track the progress of a request through a distributed system.
* Custom headers: gRPC metadata can be used to send custom headers to the server or from the server to the client. 
This can be used to implement application-specific features, such as load balancing, rate limiting or providing detailed error messages from the server to the client.
* Internal usages: gRPC uses HTTP/2 headers and trailers, which will be integrated with the metadata specified by your application.