Merge pull request #939 from Shopify/versionable-mock-fetch-response

Permit setting version on mock fetch response

mockresponses.go

@@ -180,6 +180,7 @@ type MockFetchResponse struct {
 	highWaterMarks map[string]map[int32]int64
 	t              TestReporter
 	batchSize      int
+	version        int16
 }
 
 func NewMockFetchResponse(t TestReporter, batchSize int) *MockFetchResponse {
@@ -191,6 +192,11 @@ func NewMockFetchResponse(t TestReporter, batchSize int) *MockFetchResponse {
 	}
 }
 
+func (mfr *MockFetchResponse) SetVersion(version int16) *MockFetchResponse {
+	mfr.version = version
+	return mfr
+}
+
 func (mfr *MockFetchResponse) SetMessage(topic string, partition int32, offset int64, msg Encoder) *MockFetchResponse {
 	partitions := mfr.messages[topic]
 	if partitions == nil {
@@ -218,7 +224,9 @@ func (mfr *MockFetchResponse) SetHighWaterMark(topic string, partition int32, of
 
 func (mfr *MockFetchResponse) For(reqBody versionedDecoder) encoder {
 	fetchRequest := reqBody.(*FetchRequest)
-	res := &FetchResponse{}
+	res := &FetchResponse{
+		Version: mfr.version,
+	}
 	for topic, partitions := range fetchRequest.blocks {
 		for partition, block := range partitions {
 			initialOffset := block.fetchOffset