GitHub user tzulitai opened a pull request: https://github.com/apache/flink/pull/5188
[FLINK-8296] [kafka] Rework FlinkKafkaConsumerBaseTest to not rely on Java reflection ## What is the purpose of the change Prior to this PR, reflection was mainly used to inject mocks into private fields of the `FlinkKafkaConsumerBase`, without the need to fully execute all operator life cycle methods. This was done using the `FlinkKafkaConsumerBaseTest::getConsumer(...)` method (have been removed by this PR). This, however, caused the unit tests to be too implementation-specific and hard to extend. This PR reworks the `FlinkKafkaConsumerBaseTest` to remove the reflection-based `FlinkKafkaConsumerBaseTest::getConsumer(...)` method. All tests now instantiate the `DummyFlinkKafkaConsumer` normally, and let all tests properly execute all operator life cycle methods regardless of the tested logic. ## Brief change log - Remove reflection-relying `FlinkKafkaConsumerBaseTest::getConsumer(...)` method. - Generalize the `DummyFlinkKafkaConsumer` class - Introduce the `FlinkKafkaConsumerBaseTest::setupConsumer(...)` method that iterates through all normal operator life cycle methods. - The test pattern for all unit tests in the `FlinkKafkaConsumerBaseTest` is now: 1) instantiate a `DummyFlinkKafkaConsumer`, and 2) call `setupConsumer(dummyConsumer)` to make sure the consumer goes through all life cycle methods, and instance fields are properly instantiated (instead of relying on reflection like before). ## Verifying this change Test coverage of the reworked `FlinkKafkaConsumerBaseTest` has not been touched. That unit test verifies this change. ## Does this pull request potentially affect one of the following parts: - Dependencies (does it add or upgrade a dependency): no - The public API, i.e., is any changed class annotated with `@Public(Evolving)`: no - The serializers: no - The runtime per-record code paths (performance sensitive): no - Anything that affects deployment or recovery: no - The S3 file system connector: no ## Documentation - Does this pull request introduce a new feature? no - If yes, how is the feature documented? n/a You can merge this pull request into a Git repository by running: $ git pull https://github.com/tzulitai/flink FLINK-8296 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/flink/pull/5188.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #5188 ---- commit 620d500b1a14f8f5016e56fdc3d65d853ce8848d Author: Tzu-Li (Gordon) Tai <tzulitai@...> Date: 2017-12-20T00:10:44Z [FLINK-8296] [kafka] Rework FlinkKafkaConsumerBaseTest to not rely on Java reflection Reflection was mainly used to inject mocks into private fields of the FlinkKafkaConsumerBase, without the need to fully execute all operator life cycle methods. This, however, caused the unit tests to be too implementation-specific. This commit reworks the FlinkKafkaConsumerBaseTest to remove test consumer instantiation methods that rely on reflection for dependency injection. All tests now instantiate dummy test consumers normally, and let all tests properly execute all operator life cycle methods regardless of the tested logic. ---- ---