android/app/src/test/java/com/fabledsword/minstrel/shared/UpdateVeilControllerTest.kt

@@ -7,7 +7,6 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.test.TestScope
 import kotlinx.coroutines.test.advanceTimeBy
-import kotlinx.coroutines.test.advanceUntilIdle
 import kotlinx.coroutines.test.runCurrent
 import kotlinx.coroutines.test.runTest
 import org.junit.jupiter.api.Test
@@ -22,6 +21,13 @@ private const val ART_IN_FLIGHT = 3
 private const val SUCCEED_ON_ATTEMPT = 3
 private const val QUIET_WINDOWS_TO_OUTLAST = 3
 
+// Time to let a session finish once the screen has stopped changing: the
+// retry backoffs, the quiet window and the minimum hold all fit inside it,
+// while staying well under maxHoldMs. That gap matters — if a drain ran
+// past the ceiling, "the veil lowered" would no longer distinguish
+// "it settled" from "it gave up", which is the whole point of these tests.
+private const val DRAIN_MS = 3_000L
+
 /**
  * The veil's job is to stay up until the screen has stopped moving. Each
  * test pins one of the ways the previous fixed-delay implementation
@@ -30,6 +36,14 @@ private const val QUIET_WINDOWS_TO_OUTLAST = 3
  * The controller is built on `backgroundScope` throughout: its consumer
  * loop runs forever, so hanging it off the test's own scope would stop
  * `runTest` from ever completing.
+ *
+ * Consequence, and the reason every wait below is an explicit
+ * `advanceTimeBy`: **`advanceUntilIdle()` is useless here.** It advances
+ * only while *foreground* work remains, and everything this controller
+ * does lives in `backgroundScope` — so it returns having run nothing, and
+ * assertions land on a session that never started (CI run 3163 failed all
+ * seven of these with "expected 3, actual 0" and friends). Drive the clock
+ * deliberately instead; don't "simplify" these back to advanceUntilIdle.
  */
 @OptIn(ExperimentalCoroutinesApi::class)
 class UpdateVeilControllerTest {
@@ -101,7 +115,7 @@ class UpdateVeilControllerTest {
             assertTrue(controller.visible.value, "veil must hold across staged churn")
         }
 
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertFalse(controller.visible.value, "veil lowers once the screen goes quiet")
     }
 
@@ -118,7 +132,7 @@ class UpdateVeilControllerTest {
         assertTrue(controller.visible.value, "veil must wait on in-flight art")
 
         screen.artLoading(0)
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertFalse(controller.visible.value, "veil lowers once art has landed")
     }
 
@@ -138,7 +152,7 @@ class UpdateVeilControllerTest {
         advanceTimeBy(timings.retryBackoffMs + 1)
         assertTrue(controller.visible.value, "veil stays up across the backoff")
 
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertEquals(SUCCEED_ON_ATTEMPT, attempts, "retries until the pull succeeds")
         assertEquals(listOf(false, true, false), seen, "raised once, lowered once")
     }
@@ -154,7 +168,7 @@ class UpdateVeilControllerTest {
         }
 
         controller.request()
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertEquals(timings.attempts, attempts, "exhausts its attempts")
         assertFalse(controller.visible.value, "gives up silently")
 
@@ -162,7 +176,7 @@ class UpdateVeilControllerTest {
         // — the reconnect-driven recovery still gets to try again later.
         succeed = true
         controller.request()
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertEquals(timings.attempts + 1, attempts, "a later request still runs")
     }
 
@@ -186,7 +200,7 @@ class UpdateVeilControllerTest {
         advanceTimeBy(WORK_MS + 1)
         assertTrue(controller.visible.value, "second trigger extends the same veil")
 
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertEquals(2, started, "the mid-session trigger still did its pull")
         assertEquals(listOf(false, true, false), seen, "one veil session, not two")
     }
@@ -215,7 +229,7 @@ class UpdateVeilControllerTest {
         }
 
         controller.request()
-        advanceUntilIdle()
+        advanceTimeBy(DRAIN_MS)
         assertTrue(ran, "the refresh still happens")
         assertFalse(controller.visible.value, "but no veil over a skeleton")
     }
@@ -236,7 +250,7 @@ class UpdateVeilControllerTest {
         runCurrent()
         assertTrue(controller.visible.value, "raises the moment cached content paints")
 
-        advanceUntilIdle()
+        advanceTimeBy(SLOW_WORK_MS + DRAIN_MS)
         assertFalse(controller.visible.value)
     }
 }