Question about adapting callback to suspend api. I have the following code below adapting javascript

FileReader

to suspend. Does this look good? • Should I cancel the continuation when the underlying resource is aborted (ie. by the browser) ? • Is this sequence safe ?

continuation.invokeOnCancellation -> abort() -> onabort -> continuation.cancel()

suspend fun Blob.readAsDataUrl2(): String {
    val fileReader = FileReader()
    return suspendCancellableCoroutine { continuation ->
        fileReader.onload = {
            val dataUrl = fileReader.result as String
            continuation.resume(dataUrl)
        }
        fileReader.onerror = {
            continuation.resumeWithException(DomExceptionThrowable(fileReader.error as DOMException))
        }
        fileReader.onabort = {
            continuation.cancel()
        }
        continuation.invokeOnCancellation { fileReader.abort() }

        fileReader.readAsDataURL(this) // <-- Async work starts here
    }
}

Calling

cancel

from

invokeOnCancellation

whould not do anything. It is already cancelled.

The documentation isnt really clear on if it can happen or not. I guess you are right though that its more of an error.