Running a coroutine inside of a lambda

Question

In this Kotlin code:

async {
    lateinit var testResult: TestResult
    val startTime = Date()

    try {
        withContext(Dispatchers.IO) {
            unitTest.getTestToRunAsync()?.invoke { result ->
                testResult = result
                doOnTestCompleted(testInfo, testResult, startTime, Date())
            }
        }
    } catch (exception: Exception) {
        testResult = TestResult("Exception: ${exception.message}")
    }
}

I want to call doOnTestCompleted, which is defined like this:

private suspend fun doOnTestCompleted(
    testInfo: TestInfo,
    testResult: TestResult,
    startTime: Date,
    endTime: Date,
    copyTestResults: Boolean = true
) {

}

But I cannot call doOnTestCompleted because the lambda body where it is being called from is not a coroutine. The definition for getTestToRunAsync is:

fun getTestToRunAsync(): (suspend (testToRunAsync: (resultCallback: TestResult) -> Unit) -> Unit)? {
    return this.testToRunAsync
}

How can I call doOnTestCompleted?

Answer 1

You can do it like this

async {
    lateinit var testResult: TestResult
    val startTime = Date()

    try {
        withContext(Dispatchers.IO) {
            unitTest.getTestToRunAsync()?.invoke { result ->
                testResult = result
                launch { doOnTestCompleted(testInfo, testResult, startTime, Date()) }
            }
        }
    } catch (exception: Exception) {
        testResult = TestResult("Exception: ${exception.message}")
    }
}

Because inside lambda you still have access to CoroutineScope from async. If this approach is not good and you elaborate more restrictions we can think it further out (:

Also if you'd tell more what are you trying to achieve maybe we can find better solution. If not, hope it helps anyway!