Fix payload normalization in http.request events. Closes #434 (#459)

event/event.go

@@ -59,7 +59,7 @@ func New(eventType TypeName, mimeType string, payload interface{}) *Event {
 		},
 	}
 
-	event.enhanceEventData()
+	event.Data = normalizePayload(event.Data, event.ContentType)
 	return event
 }
 
@@ -101,7 +101,7 @@ func FromRequest(r *http.Request) (*Event, error) {
 		return New(TypeName(r.Header.Get("event")), mimeType, body), nil
 	}
 
-	return New(TypeHTTPRequest, mimeCloudEventsJSON, NewHTTPRequestData(r, body)), nil
+	return New(TypeHTTPRequest, mimeJSON, NewHTTPRequestData(r, body)), nil
 }
 
 // Validate Event struct
@@ -199,7 +199,7 @@ func parseAsCloudEventBinary(headers http.Header, payload interface{}) (*Event,
 		}
 	}
 
-	event.enhanceEventData()
+	event.Data = normalizePayload(event.Data, event.ContentType)
 	return event, nil
 }
 
@@ -217,7 +217,7 @@ func parseAsCloudEvent(mime string, payload interface{}) (*Event, error) {
 			return nil, err
 		}
 
-		event.enhanceEventData()
+		event.Data = normalizePayload(event.Data, event.ContentType)
 		return event, nil
 	}
 
@@ -231,17 +231,23 @@ const (
 	mimeCloudEventsJSON = "application/cloudevents+json"
 )
 
-// Because event.Data is []byte, it will be base64 encoded by default when being sent to remote function,
-// which is why we change the event.Data type to "string" for forms or to map[string]interface{} for JSON
-// so that, it is left intact.
-func (e *Event) enhanceEventData() {
-	contentType := e.ContentType
-	if eventBody, ok := e.Data.([]byte); ok && len(eventBody) > 0 {
+// normalizePayload takes anything, checks if it's []byte array and depending on provided mime
+// type converts it to either string or map[string]interface to avoid having base64 string after
+// JSON marshaling.
+func normalizePayload(payload interface{}, mime string) interface{} {
+	if bytePayload, ok := payload.([]byte); ok && len(bytePayload) > 0 {
 		switch {
-		case contentType == mimeJSON || strings.HasSuffix(contentType, "+json"):
-			json.Unmarshal(eventBody, &e.Data)
-		case strings.HasPrefix(contentType, mimeFormMultipart), contentType == mimeFormURLEncoded:
-			e.Data = string(eventBody)
+		case mime == mimeJSON || strings.HasSuffix(mime, "+json"):
+			var result map[string]interface{}
+			err := json.Unmarshal(bytePayload, &result)
+			if err != nil {
+				return payload
+			}
+			return result
+		case strings.HasPrefix(mime, mimeFormMultipart), mime == mimeFormURLEncoded:
+			return string(bytePayload)
 		}
 	}
+
+	return payload
 }

event/event_test.go

@@ -268,22 +268,24 @@ var fromRequestTests = []struct {
 		},
 	},
 	{
-		name: "regular HTTP request",
+		name: "regular HTTP JSON request",
 		requestHeaders: http.Header{
 			"Content-Type": []string{"application/json"},
 		},
-		requestBody: []byte("hey there"),
+		requestBody: []byte(`{"key": "value"}`),
 		expectedEvent: &eventpkg.Event{
 			EventType:          eventpkg.TypeHTTPRequest,
 			CloudEventsVersion: "0.1",
 			Source:             "https://serverless.com/event-gateway/#transformationVersion=0.1",
-			ContentType:        "application/cloudevents+json",
+			ContentType:        "application/json",
 			Data: &eventpkg.HTTPRequestData{
 				Headers: map[string]string{
 					"Content-Type": "application/json",
 				},
 				Query: map[string][]string{},
-				Body:  []byte("hey there"),
+				Body: map[string]interface{}{
+					"key": "value",
+				},
 			},
 			Extensions: map[string]interface{}{
 				"eventgateway": map[string]interface{}{"transformed": "true", "transformation-version": "0.1"}},

event/http.go

@@ -19,12 +19,15 @@ type HTTPRequestData struct {
 
 // NewHTTPRequestData returns a new instance of HTTPRequestData
 func NewHTTPRequestData(r *http.Request, eventData interface{}) *HTTPRequestData {
-	return &HTTPRequestData{
+	req := &HTTPRequestData{
 		Headers: ihttp.FlattenHeader(r.Header),
 		Query:   r.URL.Query(),
 		Body:    eventData,
 		Host:    r.Host,
 		Path:    r.URL.Path,
 		Method:  r.Method,
 	}
+
+	req.Body = normalizePayload(req.Body, r.Header.Get("content-type"))
+	return req
 }