Fix MetricsPingSchedulerTest failing between midnight and 4am - #3611
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rvandermeulen wants to merge 1 commit into
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Fix MetricsPingSchedulerTest failing between midnight and 4am#3611rvandermeulen wants to merge 1 commit into
rvandermeulen wants to merge 1 commit into
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The scheduler reads "now" from Calendar.getInstance(), which Robolectric cannot shadow, while DateUtils.isToday() does see the simulated clock. Tests that set a fake time got a mix of the two, so startup collection only happened when the real local hour was past DUE_HOUR_OF_THE_DAY (4). Add a test-only clock override so the scheduler sees the simulated time.
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For the record, this has been annoying me for AGES. |
rvandermeulen
enabled auto-merge (rebase)
August 27, 2026 04:32
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MetricsPingSchedulerreads "now" fromCalendar.getInstance(), which Robolectric cannot shadow, whileDateUtils.isToday()does see the clock set bySystemClock.setCurrentTimeMillis(). Tests that install a fake time therefore got a mix of the simulated and real clocks.The visible effect is in
schedule(): startup collection only happens whenisAfterDueTime(now)is true, andnowwas the real time. Between midnight andDUE_HOUR_OF_THE_DAY(4am) local, the ping was scheduled for later in the day instead of collected immediately, so the mock web server never received it,takeRequesttimed out after 20s and!!threw an NPE.This affects
Data recorded before Glean inits must not get into overdue pingsandGlean must preserve lifetime application metrics across runs. It looks like a flake but is deterministic — it depends only on the local hour the suite runs at, which is a ~4h window per day for a UTC CI.getCalendarInstance()already existed as a seam, but the instance Glean builds instartMetricsPingScheduler()is not reachable from tests, so this adds a test-onlyclockOverridethat it consults. It is null in production, so there is no behavior change outside tests.GleanTestRulesets it alongside theSystemClockcall it already makes and clears it infinished().Verified by running the full
:glean:testDebugUnitTestsuite plusdetektandktlintat 00:24 and 00:28 local — inside the window where these tests failed at 00:02.