单元测试挂起coroutine

Question

对Kotlin来说有点新，并测试它...我试图使用suspend方法测试dao对象包装器，该方法对SQL返回对象使用awaitFirst（）。然而，当我为它编写单元测试时，它只是停留在一个循环中。我认为这是由于awaitFirst（）不在相同的测试范围内

suspend fun queryExecution(querySpec: DatabaseClient.GenericExecuteSpec): OrderDomain {
        var result: Map<String, Any>?
        try {
            result = querySpec.fetch().first().awaitFirst()
        } catch (e: Exception) {
            if (e is DataAccessResourceFailureException)
                throw CommunicationException(
                    "Cannot connect to " + DatabaseConstants.DB_NAME +
                        DatabaseConstants.ORDERS_TABLE + " when executing querySelect",
                    "querySelect",
                    e
                )
            throw InternalException("Encountered R2dbcException when executing SQL querySelect", e)
        }

        if (result == null)
            throw ResourceNotFoundException("Resource not found in Aurora DB")

        try {
            return OrderDomain(result)
        } catch (e: Exception) {
            throw InternalException("Exception when parsing to OrderDomain entity", e)
        } finally {
            logger.info("querySelect;stage=end")
        }
    }

@Test
    fun `get by orderid id, null`() = runBlocking {
        // Assign
        Mockito.`when`(fetchSpecMock.first()).thenReturn(monoMapMock)
        Mockito.`when`(monoMapMock.awaitFirst()).thenReturn(null)

        // Act & Assert
        val exception = assertThrows<ResourceNotFoundException> {
            auroraClientWrapper.queryExecution(
                databaseClient.sql("SELECT * FROM orderTable WHERE orderId=:1").bind("1", "123") orderId
            )
        }
        assertEquals("Resource not found in Aurora DB", exception.message)
    }

private suspend fun queryExecution(querySpec: DatabaseClient.GenericExecuteSpec): Map {
        var result: Map<String, Any>?
        try {
            result = withContext(Dispatchers.Default) {
                querySpec.fetch().first().block()
            }
return result
}

这是否意味着withContext将利用一个新线程，并在其他地方重用旧线程？这并没有真正优化任何东西，因为我仍然会有一个线程被阻塞，而不管产生一个新的上下文？

Answer 1

找到了解决办法。

monomapmock是来自Mockito的模拟值。似乎kotlinx-test coroutines不能拦截异步返回单声道。所以我强制我可以模拟的方法返回一个真实的单值，而不是模拟的单值。按照路易斯的建议。我停止嘲笑它，返回一个真正的值

@Test
    fun `get by orderid id, null`() = runBlocking {
        // Assign
        Mockito.`when`(fetchSpecMock.first()).thenReturn(Mono.empty())
        Mockito.`when`(monoMapMock.awaitFirst()).thenReturn(null)

        // Act & Assert
        val exception = assertThrows<ResourceNotFoundException> {
            auroraClientWrapper.queryExecution(
                databaseClient.sql("SELECT * FROM orderTable WHERE orderId=:1").bind("1", "123") orderId
            )
        }
        assertEquals("Resource not found in Aurora DB", exception.message)
    }