prathyushreddylpr opened a new pull request, #15105:
URL: https://github.com/apache/druid/pull/15105

   ### Description
   Fixed the flaky test `testDateHandling` inside `TimestampsParquetReaderTest` 
class. 
   
   
https://github.com/prathyushreddylpr/druid/blob/ad32f8458670339808a3136a9578a10a52b8394f/extensions-core/parquet-extensions/src/test/java/org/apache/druid/data/input/parquet/TimestampsParquetReaderTest.java#L40
   
   #### Root Cause
   The test `testDateHandling` has been reported as flaky when run with the 
[NonDex](https://github.com/TestingResearchIllinois/NonDex) tool. The test 
failed because it is trying to compare two Json strings, but since the JSON 
library used here is internally using HashMap. The HashMap in Java is 
implemented in such a way that it does not store the order in which the keys 
and values are inserted. As a result, when the expected Json string(which is 
hard-coded) is compared with the actual one, it caused the failure. 
   
   #### Fix
   This test is fixed using the Jackson library which contains classes JsonNode 
and ObjectMapper. These are used to parse two JSON strings to tree models and 
then compare these trees node by node. So when we use this, the order of the 
elements in the JSON strings is ignored and only the content is checked.
   
   ### How this has been tested?
   
   **Java:** openjdk version "11.0.20.1"
   **Maven:** Apache Maven 3.6.3
   
   1) **Module build** - Successful
   Command used - 
   ```
   mvn install -pl infra/common -am -DskipTests
   ```
   
   2) **Regular test**  - Successful
   Command used - 
   ```
   mvn -pl extensions-core/parquet-extensions test 
-Dtest=org.apache.druid.data.input.parquet.TimestampsParquetReaderTest#testDateHandling
   ```
   
   3) **NonDex test**  - Failed
   Command used - 
   ```
   mvn -pl extensions-core/parquet-extensions 
edu.illinois:nondex-maven-plugin:2.1.1:nondex 
-Dtest=org.apache.druid.data.input.parquet.TimestampsParquetReaderTest#testDateHandling
   ```
   
   NonDex test passed after the fix.
   
   
   
   <!-- If there was a discussion of the design of the feature implemented in 
this PR elsewhere (e. g. a "Proposal" issue, any other issue, or a thread in 
the development mailing list), link to that discussion from this PR description 
and explain what have changed in your final design compared to your original 
proposal or the consensus version in the end of the discussion. If something 
hasn't changed since the original discussion, you can omit a detailed 
discussion of those aspects of the design here, perhaps apart from brief 
mentioning for the sake of readability of this PR description. -->
   
   <!-- Some of the aspects mentioned above may be omitted for simple and small 
changes. -->
   
   
   <!-- Check the items by putting "x" in the brackets for the done things. Not 
all of these items apply to every PR. Remove the items which are not done or 
not relevant to the PR. None of the items from the checklist below are strictly 
necessary, but it would be very helpful if you at least self-review the PR. -->
   
   This PR has:
   
   - [x] been self-reviewed.
   - [x] added unit tests or modified existing tests to cover new code paths, 
ensuring the threshold for [code 
coverage](https://github.com/apache/druid/blob/master/dev/code-review/code-coverage.md)
 is met.
   
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to