Details
Major Description
Context
KStreamTestDriver TopologyTestDriver (added via KIP-247) is being used to unit test topologies while developing KStreams apps.
One such topology uses a Pattern to consume from multiple topics at once.
Problem
The unit test of the topology fails because KStreamTestDriver TopologyTestDriver fails to deal with Patterns properly.
Example
Underneath is a unit test explaining what I understand should happen, but is failing.
*Note: the example below is outdate as it used the old KStreamTestDriver. The overall test layout can be adopted for TopologyTestDriver though, thus, we just leave it in the description.*
Explicitly adding a source topic matching the topic pattern, generates an exception as the topology builder explicitly checks overlapping topic names and patterns, in any order of adding pattern and topic. So, it is intended behaviour.
@Test
public void shouldProcessFromSourcesThatDoMatchThePattern() {
// -- setup stream pattern
final KStream<String, String> source = builder.stream(Pattern.compile("topic-source-\\d"));
source.to("topic-sink");
// -- setup processor to capture results
final MockProcessorSupplier<String, String> processorSupplier = new MockProcessorSupplier<>();
source.process(processorSupplier);
// -- add source to stream data from
//builder.addSource(builder.newName(KStreamImpl.SOURCE_NAME), "topic-source-3");
// -- build test driver
driver = new KStreamTestDriver(builder); // this should be TopologyTestDriver
driver.setTime(0L);
// -- test
driver.process("topic-source-3", "A", "aa");
// -- validate
// no exception was thrown
assertEquals(Utils.mkList("A:aa"), processorSupplier.processed);
}
Solution
If anybody can help in defining the solution, I can create a pull request for this change.-
Attachments
Issue Links
- is related to
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KAFKA-3625 Move kafka-streams test fixtures into a published package
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- Resolved
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- links to