Github user bbende commented on the issue:
https://github.com/apache/nifi/pull/2533
The TestRunner should have the methods you are looking for...
/**
* Copies the content from the given byte array into memory and creates
a
* FlowFile from this content with no attributes and adds this FlowFile
to
* the Processor's Input Queue
*
* @param data to enqueue
*/
MockFlowFile enqueue(byte[] data);
https://github.com/apache/nifi/blob/master/nifi-mock/src/main/java/org/apache/nifi/util/TestRunner.java---
