AcceptanceTestSuite: suppress logs per test, only emit on failure

[Copilot]

The AcceptanceTestSuite emits voluminous INFO-level logs for every test case, making CI output noisy and failures harder to diagnose.

Approach

Buffer all java.util.logging output during each individual test and replay it only when that test fails. Log suppression can be disabled via a system property for debugging purposes.

Changes

• CapturingLogHandler (new inner static class) — a JUL Handler that accumulates LogRecords in a synchronized ArrayList; drainRecords() atomically snapshots and clears the buffer.
• AcceptanceTest.run() — wraps each test execution with log capture:
  • Always emits a "Running test {}, filename : {}" line before suppression begins, so test progress is always visible.
  • Saves and sets all root-logger handler levels to OFF before the test runs.
  • Installs CapturingLogHandler on the root logger.
  • On failure: restores handler levels and replays the full buffered record set through them.
  • On success: silently discards the buffer.
• -Datest.verbose=true system property — when set, bypasses the log-capturing/suppression block entirely so all logs flow normally to the existing handlers. Follows the same convention as -DskipAT and -Datest.skipslow. Default is false (suppress per-test, replay only on failure).

No new dependencies — uses only java.util.logging APIs.

// Before test: silence existing handlers, start capturing (unless -Datest.verbose=true)
if (!verboseLogging) {
    for (int i = 0; i < existingHandlers.length; i++) {
        originalLevels[i] = existingHandlers[i].getLevel();
        existingHandlers[i].setLevel(Level.OFF);
    }
    capturingHandler = new CapturingLogHandler();
    rootLogger.addHandler(capturingHandler);
}

// ... test runs ...

// In finally: restore, then conditionally replay
if (!verboseLogging) {
    for (int i = 0; i < existingHandlers.length; i++) {
        existingHandlers[i].setLevel(originalLevels[i]);
    }
    if (testFailed) {
        for (LogRecord record : capturingHandler.drainRecords()) {
            for (Handler handler : existingHandlers) {
                handler.publish(record);
            }
        }
    }
}

[chrjohn]

@copilot
Cloud you please add a system property that turns the logging back on. It should be off by default. See property skipAT as reference.

[Copilot]

@copilot
Cloud you please add a system property that turns the logging back on. It should be off by default. See property skipAT as reference.

Done in d784f8d. Added ATEST_VERBOSE_KEY = "atest.verbose" following the same pattern as skipAT/atest.skipslow. Pass -Datest.verbose=true to bypass the capturing logic entirely and have all logs flow normally; the default (false) keeps the existing suppress-and-replay-on-failure behaviour.