Fix for async deletion of non-existent resource

[EronWright]

This PR fixes an error that occurs in the deletion of a (non-existent) Azure resource. The issue impacts resources that have an async-style DELETE call (as is the case for Subnet, see schema). The technical detail is that the 404 may come in the initial response as opposed to during polling, and that wasn't handled correctly..

The user-facing error is:

  azure-native:network:Subnet (subnet):
    error: the operation failed or was cancelled

The call to runtime.NewPoller should not be made with a failed response, otherwise we hit a precondition within it:

	// this is a back-stop in case the swagger is incorrect (i.e. missing one or more status codes for success).
	// ideally the codegen should return an error if the initial response failed and not even create a poller.
	if !poller.StatusCodeValid(resp) {
		return nil, errors.New("the operation failed or was cancelled")
	}

To fix, I encapsulated the request-to-final-response logic into an anonymous function, to be able to uniformly check for the 404 result. And I ensure that the initial response was successful before making a poller.

This PR relaxes the logic for detecting a 404 during resource deletion, to not care about the specific error code. I find that at least two codes are possible: ResourceNotFound and ResourceGroupNotFound. Note that the sync path did not check the error code anyway and a uniform solution is desirable.

TODO:

• new unit tests
• manual testing for various types of resources (w/ sync and async delete operations).

Closes #3978
See also: #3783

[github-actions]

Does the PR have any schema changes?

Looking good! No breaking changes found.
No new resources/functions.

[EronWright]

This fix is actually a follow-up to #3783. I think it is justifiably in here because the Delete call is being similarly fixed here.

[thomas11]

nice catch!

[EronWright]

When we fake an error response, it is good to use the error schema because you can make assertions about the final error code.

[codecov]

Codecov Report

Attention: Patch coverage is 73.91304% with 6 lines in your changes missing coverage. Please review.

Project coverage is 57.47%. Comparing base (b512293) to head (4fd3fc6).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
provider/pkg/azure/client_azcore.go	73.91%	4 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3980      +/-   ##
==========================================
- Coverage   57.49%   57.47%   -0.03%     
==========================================
  Files          82       82              
  Lines       13078    13081       +3     
==========================================
- Hits         7519     7518       -1     
- Misses       4984     4987       +3     
- Partials      575      576       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[thomas11]

nice catch!

[pulumi-bot]

This PR has been shipped in release v2.89.0.