fix(appupdates): recheck the forced update when the minimum version changes

apps/flipcash/shared/appupdates/src/main/kotlin/com/flipcash/app/updates/internal/GooglePlayAppUpdateController.kt

@@ -27,6 +27,9 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.drop
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
@@ -58,6 +61,20 @@ class GooglePlayAppUpdateController internal constructor(
             update?.takeIf { it.isToastEligible(lastShown) }
         }.stateIn(scope, SharingStarted.Eagerly, null)
 
+    init {
+        // The resume check reads the minimum version cached from the last fetch, and the fetch that
+        // runs on the same resume lands after it. Checking again when the minimum moves is what
+        // lets a minimum raised while the app sat in the background block it on return. The first
+        // value is left to the resume check.
+        scope.launch {
+            userFlags.resolvedFlags
+                .map { it.minimumVersion.effectiveValue }
+                .distinctUntilChanged()
+                .drop(1)
+                .collect { checkForUpdate() }
+        }
+    }
+
     override val updateDownloaded: StateFlow<Boolean>
         get() = flexibleUpdates.downloaded
 

apps/flipcash/shared/appupdates/src/test/kotlin/com/flipcash/app/updates/internal/ForcedUpdateTest.kt

@@ -45,18 +45,23 @@ class ForcedUpdateTest {
 
     private fun idleMain() = shadowOf(Looper.getMainLooper()).idle()
 
-    private fun flags(
+    private fun resolved(
         minimumVersion: Int?,
         override: FieldOverride<Int?> = FieldOverride.None,
         isStaff: Boolean = false,
-    ) {
-        val resolved = mockk<ResolvedUserFlags> {
-            every { [email protected] } returns ResolvedFlag(minimumVersion, override)
-            every { [email protected] } returns ResolvedFlag(isStaff, FieldOverride.None)
-        }
-        every { userFlags.resolvedFlags } returns MutableStateFlow(resolved)
+    ): ResolvedUserFlags = mockk {
+        every { [email protected] } returns ResolvedFlag(minimumVersion, override)
+        every { [email protected] } returns ResolvedFlag(isStaff, FieldOverride.None)
     }
 
+    private fun flags(
+        minimumVersion: Int?,
+        override: FieldOverride<Int?> = FieldOverride.None,
+        isStaff: Boolean = false,
+    ): MutableStateFlow<ResolvedUserFlags> =
+        MutableStateFlow(resolved(minimumVersion, override, isStaff))
+            .also { every { userFlags.resolvedFlags } returns it }
+
     private fun TestScope.controller() = GooglePlayAppUpdateController(
         context = activity,
         versionInfo = VersionInfo(versionCode = currentVersion),
@@ -128,6 +133,30 @@ class ForcedUpdateTest {
         assertIs<NoUpdateAvailableException>(start(controller).exceptionOrNull())
     }
 
+    @Test
+    fun `a minimum raised after the check shows the gate without another resume`() = runTest {
+        fake.setUpdateAvailable(currentVersion + 1)
+        val flags = flags(minimumVersion = currentVersion)
+        val controller = controller()
+        controller.check()
+        assertNull(controller.availableUpdate.value)
+
+        flags.value = resolved(minimumVersion = currentVersion + 1)
+        idleMain()
+
+        assertEquals(UpdateAvailability.UPDATE_AVAILABLE, controller.availableUpdate.value?.updateAvailability)
+    }
+
+    @Test
+    fun `building the controller checks nothing on its own`() = runTest {
+        fake.setUpdateAvailable(currentVersion + 1)
+        flags(minimumVersion = currentVersion + 1)
+        val controller = controller()
+        idleMain()
+
+        assertNull(controller.availableUpdate.value)
+    }
+
     @Test
     fun `starting the update opens Play's immediate flow`() = runTest {
         fake.setUpdateAvailable(currentVersion + 1)