feat(message): cleanup handler interfaces

dsl/message.go

@@ -1,5 +1,18 @@
 package dsl
 
+// type MessageHandler map[string]func(...interface{})
+
+// MessageProvider is a provider function that generates a
+// message for a Consumer given a Message context (state, description etc.)
+type MessageProvider func(Message) (interface{}, error)
+
+// MessageProviders is a list of handlers ordered by description
+type MessageProviders map[string]MessageProvider
+
+// MessageConsumer receives a message and must be able to parse
+// the content
+type MessageConsumer func(Message) error
+
 // Message is a representation of a single, unidirectional message
 // e.g. MQ, pub/sub, Websocket, Lambda
 // Message is the main implementation of the Pact Message interface.

dsl/pact.go

@@ -322,7 +322,7 @@ var checkCliCompatibility = func() {
 // A Message Producer is analagous to Consumer in the HTTP Interaction model.
 // It is the initiator of an interaction, and expects something on the other end
 // of the interaction to respond - just in this case, not immediately.
-func (p *Pact) VerifyMessageProvider(t *testing.T, request types.VerifyMessageRequest, handlers map[string]func(...interface{}) (map[string]interface{}, error)) (types.ProviderVerifierResponse, error) {
+func (p *Pact) VerifyMessageProvider(t *testing.T, request types.VerifyMessageRequest, handlers MessageProviders) (types.ProviderVerifierResponse, error) {
 	response := types.ProviderVerifierResponse{}
 
 	// Starts the message wrapper API with hooks back to the message handlers
@@ -372,7 +372,7 @@ func (p *Pact) VerifyMessageProvider(t *testing.T, request types.VerifyMessageRe
 		}
 
 		// Execute function handler
-		res, handlerErr := f()
+		res, handlerErr := f(message)
 
 		if handlerErr != nil {
 			w.WriteHeader(http.StatusServiceUnavailable)
@@ -428,7 +428,7 @@ func (p *Pact) VerifyMessageProvider(t *testing.T, request types.VerifyMessageRe
 // A Message Consumer is analagous to a Provider in the HTTP Interaction model.
 // It is the receiver of an interaction, and needs to be able to handle whatever
 // request was provided.
-func (p *Pact) VerifyMessageConsumer(message *Message, handler func(Message) error) error {
+func (p *Pact) VerifyMessageConsumer(message *Message, handler MessageConsumer) error {
 	log.Printf("[DEBUG] verify message")
 	p.Setup(false)
 

examples/messages/provider/message_pact_provider_test.go

@@ -16,8 +16,8 @@ func TestMessageProvider_Success(t *testing.T) {
 
 	// Map test descriptions to message producer (handlers)
 	// TODO: convert these all to types to ease readability
-	functionMappings := map[string]func(...interface{}) (map[string]interface{}, error){
-		"a test message": func(...interface{}) (map[string]interface{}, error) {
+	functionMappings := dsl.MessageProviders{
+		"a test message": func(m dsl.Message) (interface{}, error) {
 			fmt.Println("Calling 'text' function that would produce a message")
 			res := map[string]interface{}{
 				"content": map[string]string{