[FEATURE] Provide an additional annotation for error responses

[paulchen5]

Description

Provide an additional annotation for error responses for CRUD operations on entities as well as custom functions and actions. This would allow the developer to specify when an operation would throw a 409 for example and explain in in the documentation.

Suggested Solution

Add an additonal annotation to entity which supports a style like

@Errors:[
  {
    Operation: READ | CREATE | UPDATE | DELETE | customAction | customFunction,
    HTTPStatusCode: 409,
    Message: "ABAP",
    Reason: "I send a 409 because I like ABAP"
  },
  ....
]
entity Foo as projection on Bar;

Alternatives

No response

Additional Context

No response

[daogrady]

Hi @paulchen5 ,

thank you for your suggestion. This feature request appears to overlap with OData capabilities, which you can already enforce in the export like so:

@Capabilities.InsertRestrictions: {
  ErrorResponses: [
    { StatusCode: '409', Description: 'Conflict – entity already exists' }
  ]
}
entity Foo as projection on Bar;

I believe it may be slightly more verbose than the syntax you proposed, but please check if it covers your scenario already.

Best,
Daniel