[translation] account for nonstandard LRO status strings

The service will return “Cancelled” (with two "l"s), “Cancelling”, and “ValidationFailed”.

Here are the status strings that azure-core polling currently checks to see if the operation has reached a terminal state: https://github.com/Azure/azure-sdk-for-python/blob/master/sdk/core/azure-core/azure/core/polling/base_polling.py#L52-L54

We need to check for these nonstandard statuses or the LRO will run forever.

Options:

1. Simply map the nonstandard statuses to those of the ones checked in the get_status method:

            if status:
                if status == "ValidationFailed":
                    return "Failed"
                elif status in ["Cancelled", "Cancelling"]:
                    return "Canceled"
                return status
            else:
                raise BadResponse("No status found in body")

1. Define a custom polling method that will inherit from LROBasePolling and override the methods checking for a terminal state like here in Text Analytics: https://github.com/Azure/azure-sdk-for-python/blob/master/sdk/textanalytics/azure-ai-textanalytics/azure/ai/textanalytics/_lro.py#L32

I favor option 1, but we might need to re-evaluate if it makes sense with the current error states of the service. E.g. if we map “ValidationFailed” to a status == “Failed”, now we will throw an exception instead of just returning the JobStatusDetail when wait_until_done is called by the user.

[kristapratico]

Tentative plan (may/may not make it for beta.1). If it does not make it in time then fallback plan will be to always return JobStatusDetail.

This is the expected behavior when calling wait_until_done

Service terminal state status	Job level error?	Document level error?	SDK behavior
ValidationFailed	Yes	No, returns 0 documents in list	Throw exception with job level error details
Failed	No	Yes, per document	Return JobStatusDetail, user can inquire on each document for error
Succeeded / (maybe partiallySucceeded)	No	No	Return JobStatusDetail
Cancelled/Cancelling	No	No	Return JobStatusDetail

[kristapratico]

closed with #17738