| name | watch-gradle-tests |
| description | Watch a Gradle instrumented-test run to a verdict without hand-writing greps. Use whenever running :app:testEmulatorDebugAndroidTest or :app:connectedDebugAndroidTest in the background. |
Watching a test run to a verdict
The emulator suite takes upwards of ten minutes, so it gets backgrounded, so something has to
report on it. Do not write that something fresh each time. Use the script.
./gradlew :app:testEmulatorDebugAndroidTest --console=plain > tmp/run.log 2>&1
python .claude/skills/watch-gradle-tests/watch_tests.py tmp/run.log --once
python .claude/skills/watch-gradle-tests/watch_tests.py tmp/run.log
Each line it prints is one event: FAILED <Class>.<method> as each failure appears,
STALLED … if the log stops growing, and FINISHED + VERDICT at the end.
Why this exists
Three hand-written monitors in one afternoon each matched nothing, and each looked like a
green run:
| What was written | Why it matched nothing |
|---|
grep "(0 skipped)" | the run had 5 skipped |
grep "\S+ \[testEmulator\]" | there is no space before [testEmulator] |
... | head -25 | truncated before the verdict, and head's exit code hid it |
All three exited 0. Silence from a monitor is indistinguishable from silence from a healthy
run, so a red suite was reported as green until the log was read by hand. That is the whole
argument for a script: the patterns get fixed once, and --once proves they still match before
anything depends on them.
What it knows that a grep does not
- The XML has the last word. The console can truncate, interleave, or count a retry
(
605/600 is a real line from this repo). verdict_from_xml reads
app/build/outputs/androidTest-results/, and scopes to the newest run's own directory —
AGP keeps connected/ and managedDevice/ side by side and clears neither, so summing
everything reported a 22-test run as 74. It always prints the results' age, because a verdict
that is quietly ten minutes old is the same bug wearing a coat.
- No results at all is not zero failures. A run that dies before any test reports writes no
XML, and reading that as success is exactly how a red build gets called green.
- A stall is a result. No output for eight minutes gets reported, with a diagnosis, rather
than looking like a slow test for another twenty.
The two silent hangs, which need opposite fixes
The script separates them by whether any test has reported. Do not guess between them — the
distinction is in the output.
| Symptom | Cause | Fix |
|---|
No test ever reports, no managed AVD in adb devices | leaked managed-device slots — MDLockCount above zero with nothing running | ./gradlew --stop && rm ~/.android/avd/gradle-managed/active_gradle_devices |
| Tests ran, then stopped mid-suite | the device died under them | adb logcat -b crash — the emulator's Bluetooth stack aborting has done this here |
connectedDebugAndroidTest fails to install or hangs at once | stale ADB bridge inside the Gradle daemon | restart the emulator and ./gradlew --stop — either alone leaves it broken |
Killing a run is what leaks a slot, and every Ctrl-C adds one. Prefer letting a run finish; if
you must kill one, clear the count in the same breath rather than meeting it next time.
Related
AGENTS.md, "Building and testing" — the managed device, and why it beats a hand-started
emulator..claude/skills/watch-pr/ — the same discipline for CI: prove the poll body emits before
arming a Monitor on it.
