java_test: -ea ("assert" keyword flag) isn't customizable

dmivankov commented 3 years ago

Description of the problem / feature request:

It is not possible to (easily) disable java 1.4+ asserts in java_test targets. Easiest way is not setting -ea jvm flag, or to allow to overriding it with -da https://docs.oracle.com/en/java/javase/15/docs/specs/man/java.html#standard-options-for-java Uglier way is to (pre)configure the ClassLoader https://docs.oracle.com/javase/6/docs/api/java/lang/Class.html#desiredAssertionStatus%28%29

Feature requests: what underlying problem are you trying to solve with this feature?

assert keyword is still used in some projects, but it has major flaws

if asserts are enabled in tests but not in prod, this may introduce runtime differences, "excessive" test failures (like failures in libraries nobody cared too much about since code "works" in prod), debugging frustration, etc
assert expression evaluation depends on whether asserts are enabled, and expression may have side effects
assert status flag is set by ClassLoader, which may be hard to control or reset

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Create a java test with test body

@Test
public void test() {
  assert false;
}

It should be possible to have a flag that makes this test pass. This minimal test of course doesn't make much sense, real intended use is

make sure to not use assert statement in main or test code
be able to force asserts off in libraries to match prod runtime configuration (unless prod is expected to run with asserts on, so should be configurable)

What operating system are you running Bazel on?

NixOS

What's the output of `bazel info release`?

release 3.3.1- (@non-git)

Have you found anything relevant by searching the web?

This seems to be the place where bazel adds -ea flag https://github.com/bazelbuild/bazel/blob/11d85c0e370755e24287af66362eb18c14310231/src/main/java/com/google/devtools/build/lib/bazel/rules/java/BazelJavaSemantics.java#L598 Note that java_test.jvm_args go before it and so can't override it. Maybe just moving -ea forward is a good enough solution.

dmivankov commented 3 years ago

Actually, looks like -da:smth -ea still disables asserts in da, which is good enough as a workaround for specific assertsions.

java_test(
    ...
    jvm_flags = ["-disableassertions:com.example.SomeClass"],
)

Would still be good to be able to optionally remove all asserts.

github-actions[bot] commented 9 months ago

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dmivankov commented 7 months ago

Additionally assertions status depend on use_testrunner attribute

bazelbuild / bazel