On Thu, 11 Sep 2025 22:09:10 GMT, Andy Goryachev <ango...@openjdk.org> wrote:
> This PR removes unrelated `stderr` output in the headful test logs by
> redirecting it to an in-memory buffer. Exceptions found in the buffer can be
> checked against the expected list.
>
> In the case when any mismatch is detected, whether the type or the number of
> exceptions of particular type, the accumulated buffer gets dumped to `stderr`
> (without failing the test).
>
> ## How To
>
> To redirect stderr and later check the exceptions, surround your code with
>
> `ErrorLoggingUtility.suppressStderr()` and either
> `ErrorLoggingUtility.checkStderr()` or
> `ErrorLoggingUtility.checkAndRestoreStderr()`.
>
> To simply undo redirection, without checking, call
> `ErrorLoggingUtility.restoreStderr()`.
>
> To add the check to all the tests in the file, one can call the above
> mentioned methods inside `@BeforeEach` and `@AfterEach`.
>
> ## Miscellaneous
>
> For reviewers' convenience, the first commit contains the main change, the
> second fixes the misspelt name of the utility class, the rest are trivial.
>
> ## Questions
>
> - should we fail the current test with `Assertions.fail()` in case of a
> mismatch?
The `ErrorLoggingUtility` class manages static state, and requires users to
follow a protocol to avoid messing up its internal state. Have you considered
using a try-with-resources scope to make the API easier to use, for example:
try (var util = ErrorLoggingUtility.suppressStdErr()) {
// test something
// ...
//
util.checkWarning(NullPointerException.class);
} // internal state is restored at the end of the block
-------------
PR Comment: https://git.openjdk.org/jfx/pull/1897#issuecomment-3286382236
