Fix flaky migration tests (#2663)

app/src/test/java/mihon/core/migration/MigratorTest.kt

@@ -1,9 +1,11 @@
 package mihon.core.migration
 
+import io.kotest.assertions.nondeterministic.eventually
 import io.mockk.slot
 import io.mockk.spyk
 import io.mockk.verify
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.newSingleThreadContext
@@ -17,6 +19,7 @@ import org.junit.jupiter.api.Assertions.assertInstanceOf
 import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
+import kotlin.time.Duration.Companion.seconds
 
 class MigratorTest {
 
@@ -26,7 +29,7 @@ class MigratorTest {
     lateinit var migrationStrategyFactory: MigrationStrategyFactory
 
     @BeforeEach
-    fun initilize() {
+    fun initialize() {
         migrationContext = MigrationContext(false)
         migrationJobFactory = spyk(MigrationJobFactory(migrationContext, CoroutineScope(Dispatchers.Main + Job())))
         migrationCompletedListener = spyk<MigrationCompletedListener>(block = {})
@@ -45,7 +48,7 @@ class MigratorTest {
 
         verify { migrationJobFactory.create(capture(migrations)) }
         assertEquals(1, migrations.captured.size)
-        verify { migrationCompletedListener() }
+        eventually(2.seconds) { verify { migrationCompletedListener() } }
     }
 
     @Test
@@ -86,7 +89,7 @@ class MigratorTest {
 
         verify { migrationJobFactory.create(capture(migrations)) }
         assertEquals(2, migrations.captured.size)
-        verify { migrationCompletedListener() }
+        eventually(2.seconds) { verify { migrationCompletedListener() } }
     }
 
     @Test
@@ -114,7 +117,7 @@ class MigratorTest {
 
         verify { migrationJobFactory.create(capture(migrations)) }
         assertEquals(10, migrations.captured.size)
-        verify { migrationCompletedListener() }
+        eventually(2.seconds) { verify { migrationCompletedListener() } }
     }
 
     @Test
@@ -135,11 +138,12 @@ class MigratorTest {
 
         verify { migrationJobFactory.create(capture(migrations)) }
         assertEquals(2, migrations.captured.size)
-        verify { migrationCompletedListener() }
+        eventually(2.seconds) { verify { migrationCompletedListener() } }
     }
 
     companion object {
 
+        @OptIn(DelicateCoroutinesApi::class)
         val mainThreadSurrogate = newSingleThreadContext("UI thread")
 
         @BeforeAll