feat: support binary bodies in async plugin messages

Fixes #265

Makefile

@@ -43,7 +43,7 @@ deps: download_plugins
 download_plugins:
 	@echo "--- 🐿  Installing plugins"; \
 	./scripts/install-cli.sh
-	~/.pact/bin/pact-plugin-cli -y install https://github.com/pactflow/pact-protobuf-plugin/releases/tag/v-0.3.1
+	~/.pact/bin/pact-plugin-cli -y install https://github.com/pactflow/pact-protobuf-plugin/releases/tag/v-0.3.4
 	~/.pact/bin/pact-plugin-cli -y install https://github.com/pact-foundation/pact-plugins/releases/tag/csv-plugin-0.0.1
 	~/.pact/bin/pact-plugin-cli -y install https://github.com/mefellows/pact-matt-plugin/releases/tag/v0.0.9
 

examples/grpc/grpc_consumer_test.go

@@ -53,7 +53,7 @@ func TestGrpcInteraction(t *testing.T) {
 		Given("feature 'Big Tree' exists").
 		UsingPlugin(message.PluginConfig{
 			Plugin:  "protobuf",
-			Version: "0.3.1",
+			Version: "0.3.4",
 		}).
 		WithContents(grpcInteraction, "application/protobuf").
 		StartTransport("grpc", "127.0.0.1", nil). // For plugin tests, we can't assume if a transport is needed, so this is optional

examples/protobuf-message/protobuf_consumer_test.go

@@ -0,0 +1,54 @@
+//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)),
+	})
+
+	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").
+		UsingPlugin(message.PluginConfig{
+			Plugin:  "protobuf",
+			Version: "0.3.4",
+		}).
+		WithContents(protoMessage, "application/protobuf").
+		ExecuteTest(t, func(m message.AsynchronousMessage) error {
+			// TODO: normally would actually read/consume the message
+			return nil
+		})
+
+	assert.NoError(t, err)
+}

examples/protobuf-message/protobuf_provider_test.go

@@ -0,0 +1,58 @@
+//go:build provider
+// +build provider
+
+package protobuf
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/pact-foundation/pact-go/v2/examples/grpc/routeguide"
+	pactlog "github.com/pact-foundation/pact-go/v2/log"
+	"github.com/pact-foundation/pact-go/v2/message"
+	"github.com/pact-foundation/pact-go/v2/models"
+	"github.com/pact-foundation/pact-go/v2/provider"
+	pactversion "github.com/pact-foundation/pact-go/v2/version"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPluginMessageProvider(t *testing.T) {
+	var dir, _ = os.Getwd()
+	var pactDir = fmt.Sprintf("%s/../pacts", dir)
+
+	err := pactlog.SetLogLevel("TRACE")
+	assert.NoError(t, err)
+
+	pactversion.CheckVersion()
+
+	verifier := provider.NewVerifier()
+
+	functionMappings := message.Handlers{
+		"feature message": func([]models.ProviderState) (message.Body, message.Metadata, error) {
+			fmt.Println("feature message handler")
+			feature, _ := proto.Marshal(&routeguide.Feature{
+				Name: "fake feature",
+				Location: &routeguide.Point{
+					Latitude:  int32(1),
+					Longitude: int32(1),
+				},
+			})
+			return feature, message.Metadata{
+				"contentType": "application/protobuf;message=Feature", // <- This is required to ensure the correct type is matched
+			}, nil
+		},
+	}
+
+	err = verifier.VerifyProvider(t, provider.VerifyRequest{
+		PactFiles: []string{
+			filepath.ToSlash(fmt.Sprintf("%s/protobufmessageconsumer-protobufmessageprovider.json", pactDir)),
+		},
+		Provider:        "protobufmessageprovider",
+		MessageHandlers: functionMappings,
+	})
+
+	assert.NoError(t, err)
+}

message/verifier.go

@@ -194,6 +194,18 @@ func appendMetadataToResponseHeaders(metadata Metadata, w http.ResponseWriter) {
 
 		w.Header().Add(PACT_MESSAGE_METADATA_HEADER, encoded)
 		w.Header().Add(PACT_MESSAGE_METADATA_HEADER2, encoded)
+		// Content-Type must match the pact file if provider
+		if metadata["contentType"] != nil {
+			w.Header().Set("Content-Type", metadata["contentType"].(string))
+		} else if metadata["content-type"] != nil {
+			w.Header().Set("Content-Type", metadata["content-type"].(string))
+		} else if metadata["Content-Type"] != nil {
+			w.Header().Set("Content-Type", metadata["Content-Type"].(string))
+		} else {
+			defaultContentType := "application/json; charset=utf-8"
+			log.Println("[WARN] no content type (key 'contentType') found in message metadata. Defaulting to", defaultContentType)
+			w.Header().Set("Content-Type", defaultContentType)
+		}
 	}
 }
 
@@ -202,9 +214,6 @@ func CreateMessageHandler(messageHandlers Handlers) proxy.Middleware {
 
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			if r.URL.Path == "/__messages" {
-				// TODO: should this be set by the provider itself? How does the metadata go back?
-				w.Header().Set("Content-Type", "application/json; charset=utf-8")
-
 				log.Printf("[TRACE] message verification handler")
 
 				// Extract message
@@ -248,11 +257,17 @@ func CreateMessageHandler(messageHandlers Handlers) proxy.Middleware {
 				// Write the body back
 				appendMetadataToResponseHeaders(metadata, w)
 
-				body, errM := json.Marshal(res)
-				if errM != nil {
-					w.WriteHeader(http.StatusServiceUnavailable)
-					log.Println("[ERROR] error marshalling objcet:", errM)
-					return
+				if bytes, ok := res.([]byte); ok {
+					log.Println("[DEBUG] checking type of message is []byte")
+					body = bytes
+				} else {
+					log.Println("[DEBUG] message body is not []byte, serialising as JSON")
+					body, err = json.Marshal(res)
+					if err != nil {
+						w.WriteHeader(http.StatusServiceUnavailable)
+						log.Println("[ERROR] error marshalling object:", err)
+						return
+					}
 				}
 
 				w.WriteHeader(http.StatusOK)