[Python] handle discriminator inheritance for models

[rienafairefr]

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Description of the PR

related issues: #1662 #1663
in the Python models, discriminator_value_class_map wasn't filled when the model had a filled-up discriminator (with or without a mapping). I'm not sure about the children field for the model and what it corresponds, but adding the discriminator mapping in the case this field is not there seems to work.

[wing328]

@rienafairefr thanks for the PR. Are you free for a quick chat via https://gitter.im tomorrow (Wed)?

[rienafairefr]

Sorry @wing328 took some time to get back to you, yeah ping me up on gitter anytime :-)

[tomghyselinck]

Hi @rienafairefr,

I am testing this PR.

IMHO the mapping should also be applied when there are children defined.

According to OpenAPI Specification 3.0.2:

• The children can be used for the "schema name" or (default) "implicit" mapping.
• while the mapping is an additional mapping to identify the (final or upper-layer) objects.

With best regards,
Tom.

[fantavlik]

This is great, thanks @rienafairefr. I do agree with @tomghyselinck that implicit mapping should also be included. To me it appears that a change to the core code is actually needed, the implicit mapping is not being captured here from what I can tell: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java#L1798-L1825

This is confirmed when I generate this schema:

Thing:
  oneOf:
  - $ref: "#/components/schemas/Foo"
  - $ref: "#/components/schemas/Bar"
  discriminator:
    propertyName: kind

The discriminator template payload is simply:

...
"discriminator" : {
  "propertyName" : "kind",
  "mappedModels" : [ ]
},

Ideally it would be:

...
"discriminator" : {
  "propertyName" : "kind",
  "mappedModels" : [ {
    "mappingName" : "Foo",
    "modelName" : "Foo"
  }, {
    "mappingName" : "Bar",
    "modelName" : "Bar"
  } ]
},

[andreishappy]

I've run into this issue and would really appreciate a fix. Do you know by any chance when this could be merged? Thanks! ❤️

[spacether]

We have another PR in review which also seeks to improve the discriminator class map here
#4906

[spacether]

This PR has been closed due to inactivity