Status

Current state: "Accepted"

Discussion thread: n/a – skipped discussion and called for a vote directly

Voting thread: https://lists.apache.org/thread/ht0685l0ypg47onj90kxpzbw76vtv6ob

JIRA:

Released: 4.0

Motivation

MockProcessorContext (packed kafka-streams-test-utils) is used to test the custom processors which implement the old and already deprecated Processor interface. Both Processor and MockProcessorContext are already replace with new versions api.Processor and api.MockProcessorContext. Given that Processor is already deprecated, we should also deprecate MockProcessorContext.

Furthermore, Transformer, TransformerSupplier, ValueTransformer, and ValueTransformerSupplier, are already replaces with api.[FixedKey]Processor[Supplier] and should be deprecated to cleanup the old Processor API because KStream#transform() and KStream#transformValue() are already deprecated, too.

Public Interfaces

org.apache.kafka.streams.processor.MockProcessorContext from package kafka-stream-test-utils.

org.apache.kafka.streams.kstream.Transformer

org.apache.kafka.streams.kstream.TransformerSupplier

org.apache.kafka.streams.kstream.ValueTransformer 

org.apache.kafka.streams.kstream.ValueTransformerSupplier

Proposed Changes

We propose to deprecate MockProcessorContext, Transformer, TransformerSupplier, ValueTransformer, and ValueTransformerSupplier, so we can remove thme in a future major release (most likely 5.0).

Compatibility, Deprecation, and Migration Plan

None. We only deprecate a class for future removal in a major release.

Test Plan

n/a

Documentation Plan

Regular JavaDocs and webpage docs updates.

Rejected Alternatives

n/a