Add ability to customize the access token response

[ddubson]

Fixes gh-925

Referenced in gh-1369

Open questions:

• Does extracting an authentication success handler for OAuth 2 Token Endpoint filter enough to make access token response customizable? Or is there a need for a customization function for adding to additionalParameters.
• If the Authentication is of incorrect type, what should the HTTP response be?

[jgrandja]

@ddubson

is there a need for a customization function for adding to additionalParameters

Maybe. I see you exposed setAccessTokenHttpResponseConverter(), which would allow for adding additional parameters. I would suggest writing a test for the use case to see how easy it is. From there, we can decide if another hook is needed to allow for easier customization.

[ddubson]

@ddubson

is there a need for a customization function for adding to additionalParameters

Maybe. I see you exposed setAccessTokenHttpResponseConverter(), which would allow for adding additional parameters. I would suggest writing a test for the use case to see how easy it is. From there, we can decide if another hook is needed to allow for easier customization.

I was able to successfully customize the access token HTTP response converter and inject custom parameters (with test case exercising the customization) -- it's not the prettiest implementation, but it is concise and, in my opinion, sufficient enough for the amount of demand for this kind of functionality.

[jgrandja]

Thanks for the updates @ddubson. Please see review comments.

[jgrandja]

Almost there @ddubson ! After you update based on review comments, we should be good to merge.

[jgrandja]

Thanks for the updates @ddubson. This is now merged!