BazelTestRunner: exit with 137 on OOMs

[saraadams]

Motivation: Make it easier to detect whether a test failed due to an OutOfMemoryException

Current behavior:
The test runner exited with a code 1 on any test failure. This can make it hard to programmatically differentiate whether a test failed due to an actual test failure, or because the test was aborted due to an OutOfMemoryException.

Proposed change:
If a run of a test suite fails, the failures are checked for any OOMs. If at least one failure was caused by an OOM, the program exits with a code 137, rather than 1. Additionally, this is also the exit code if the test runner itself OOMs.

This distinction can help with automatically detecting OOMs and then retrying the execution with more memory available, and is especially helpful in the context of remote execution, where the action may be retried on a larger executor.

[hvadehra]

This seems reasonable to me. Any chance we could add a test for this?

[saraadams]

This seems reasonable to me. Any chance we could add a test for this?

I had looked, but didn't see where I could easily add a test. Do you have guidance on where/how I could add a test for this?

[saraadams]

Added a test - is that the right way to do it?

[hvadehra]

Thanks for adding the tests. Could you maybe separate out the new test into a different class? It would be preferable to not modify existing tests so we can be sure we're not inadvertently affecting something else.

[saraadams]

Thanks for adding the tests. Could you maybe separate out the new test into a different class? It would be preferable to not modify existing tests so we can be sure we're not inadvertently affecting something else.

Just so I head in the right direction:

1. Do you want me to add a separate Java test class for the OOM test case? If I keep the current change and reverted the changes to junit4_testbridge_integration_tests.sh that should still pass.
2. Do you want me to add a separate test case in the existing src/java_tools/junitrunner/javatests/com/google/testing/junit/runner/junit4_testbridge_integration_tests.sh or do you want me to add a separate .sh? It looks to me like adding a separate test function would be sufficient.

[hvadehra]

A separate java test class and new test case in the same sh file SG.

[saraadams]

A separate java test class and new test case in the same sh file SG.

PTAL.

[hvadehra]

Thanks!