test: Fix flows that emit Units

Author: Mr3zee

krpc/krpc-test/src/commonMain/kotlin/kotlinx/rpc/krpc/test/KrpcTestService.kt

@@ -113,6 +113,8 @@ interface KrpcTestService : RemoteService {
 
     suspend fun krpc173()
 
+    fun unitFlow(): Flow<Unit>
+
     val plainFlowOfInts : Flow<Int>
 
     val plainFlowOfFlowsOfInts : Flow<Flow<Int>>

krpc/krpc-test/src/commonMain/kotlin/kotlinx/rpc/krpc/test/KrpcTestServiceBackend.kt

@@ -282,6 +282,12 @@ class KrpcTestServiceBackend(override val coroutineContext: CoroutineContext) :
         doWork()
     }
 
+    override fun unitFlow(): Flow<Unit> {
+        return flow {
+            emit(Unit)
+        }
+    }
+
     override val plainFlowOfInts: Flow<Int> = plainFlow { it }
 
     override val plainFlowOfFlowsOfInts: Flow<Flow<Int>> = plainFlow { plainFlow { i -> i } }

krpc/krpc-test/src/commonMain/kotlin/kotlinx/rpc/krpc/test/KrpcTransportTestBase.kt

@@ -569,6 +569,11 @@ abstract class KrpcTransportTestBase {
         assertEquals(Unit, client.krpc173())
     }
 
+    @Test
+    fun testUnitFlow() = runTest {
+        assertEquals(Unit, client.unitFlow().toList().single())
+    }
+
     @Test
     fun testPlainFlowOfInts() = runTest {
         val flow = client.plainFlowOfInts.toList()