NIFI-5862 MockRecordParser Has Bad Logic for failAfterN

[patricker]

MockRecordParser has a function that allows it to throw an exception after a certain number of records have been read. This feature is not working at all, and instead the reader fails immediately without reading any records.

The two unit tests that use this (TestSplitRecord.testReadFailure and TestConvertRecord.testReadFailure) both work because they route to Failure on any error in the read, but you can see the error in the console.

Also, I'm working on a custom processor using this test class for testing. My processor interfaces with an external system and sends batches of data. In some cases a read failure could cause a partial load to a remote system, and we need to be able to check for this.

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[ijokarumawak]

Thanks @patricker good catch! +1 merging to master.