Support to add properties in @Schema

[MarvGilb]

For Maps it should be possible to set known properties to the generated documentation.

e.g.:

@Schema(description = "A map with known and custom properties.")
private Map<String, Object> map = new TreeMap<>();

returns an output like:

map:
  type: object
  additionalProperties:
    type: object
    description: A map with known and custom properties.
  description": A map with known and custom properties.

But required is an output with known properties like this:

map:
  type: object
  properties:
    knownValue1:
      type: string
    knownValue2:
      type: string
  additionalProperties:
    type: object
    description: A map with known and custom properties.
  description": A map with known and custom properties.

Therefore '@Schema' should get an additional variable that allows to override or add properties.

[eddsteel]

I have the almost exact opposite problem, of wanting to add custom properties to a schema with fixed fields, i.e. to add additionalProperties to an object with properties already correctly generated.

I think a solution to this would be to allow setting additionalProperties inside @Schema, as well as allowing adding properties there.

[frantuma]

#4129 introduces support to define Schema properties via annotations. Please see this and this examples for usage scenarios.