Added 501 Not Supported error response

[mhfoo]

What type of PR is this?

Add one of the following kinds:

• enhancement

What this PR does / why we need it:

Enhancement as per #138 Proposal to add 501 Not Supported error response

Which issue(s) this PR fixes:

Fixes #138

Special notes for reviewers:

Changelog input

release-note
+ Add 501 Not Supported error response

Additional documentation

This section can be blank.

docs

[mhfoo]

@rartych @shilpa-padgaonkar @patrice-conil @RubenBG7 @PedroDiez

Kindly review this pull request for merging please.

[PedroDiez]

Suggested change

	NotSupported:
	PhoneNumberNotSupported:

[mhfoo]

@PedroDiez
Suggest not to be specific to "phoneNumber", so this error can be reused.

[PedroDiez]

To be aligned with Issue#127 output (so far 422)

[mhfoo]

@PedroDiez
Understand there is a difference between 4xx and 5xx HTTP error codes.

The 4xx codes are intended for cases in which the client has erred, and the 5xx codes for the cases in which the server is aware that the server has erred.

In this context, the client cannot "correct" the request as the server is not supporting this specific request.

See 400 vs 500

[hdamker]

@mhfoo please see my comment #127 (comment) regarding your same statement there. 422 with appropriate description is definitely more helpful for the client then 501.

[eric-murray]

I think 501 is appropriate for functionality that has not yet been implemented, but will be (or, at least, could be) implemented at some point in the future, whereas a 4XX error should be returned for a request that will never make sense and will never be supported (such as requesting SIM Swap status for a landline).

However desirable it is that all implementations support all possible functionality from the start, I do not think that will be the case.

So I support using a 501 error in some circumstances where a phone number is not supported, but only if it will be supported at a later date.

[PedroDiez]

Suggested change

	code: NOT_SUPPORTED
	code: PHONE_NUMBER_NOT_SUPPORTED

[mhfoo]

@PedroDiez
Suggest not to be specific to "Phone_Number", so this error can be reused.

[rartych]

@mhfoo As we agreed on the last Commonalities meeting could you modify your proposal to:

  NotSupported:
   description: Not Supported
   content:
    application/json:
     schema:
      $ref: "#/components/schemas/ErrorInfo"
     example:
      status:  422
      code: NOT_SUPPORTED
      message: Service not supported for this device

Further discussion is possible, but for now we have consensus to use 422.

[mhfoo]

@mhfoo As we agreed on the last Commonalities meeting could you modify your proposal to:

  NotSupported:
   description: Not Supported
   content:
    application/json:
     schema:
      $ref: "#/components/schemas/ErrorInfo"
     example:
      status:  422
      code: NOT_SUPPORTED
      message: Service not supported for this device

Further discussion is possible, but for now we have consensus to use 422.

@rartych

In last Commonalities meeting, my statement are as follows:

I do not want my PR #145 to block this coming meta-release (Fall24) of Commonalities. Please continue this PR #145 discussion for the next release (Spring25).

[rartych]

@mhfoo Thank you for clarification, I got it wrong.
Let's postpone this PR as you suggest.

[hdamker]

@rartych @shilpa-padgaonkar propose to "convert to draft" if this is not an active review