Feature/87 support enums in generators

[thowimmer]

Fixes #87 (comment)

[coveralls]

Coverage increased (+0.02%) to 92.063% when pulling 02b62b9 on thowimmer:feature/87-support-enums-in-generators into 21213ef on ePages-de:master.

[thowimmer]

Hey @ozscheyge ,

did you already took a look into this PR ? Any change to get this functionality merged and probably released by the end of this week ? I would have some spare time this week :-)

[ozscheyge]

Hey @thowimmer ,

I had a brief look, but realized I first need to better research how possible enum values are modeled in OpenAPI 2/3 before giving feedback.

I'm quite busy atm, but I'll take care of it tomorrow, so it could be done before end of the week.

[thowimmer]

Sure, no worries. I'm glad for any feedback and improvements. We can also have a more in-deep discussion if you like.

Here just some things to mention:

• This PR only covers enum support for fields in request/response bodies.The OpenAPI spec (both v2 and v3) also support enums for other kind of parameters (header params, query params etc).

• Both generators are mapping to the corresponding models based on the JSON schema which is generated via the JsonSchemaFromFieldDescriptorsGenerator. In order that the mapping works properly, without the need of further code changes, the 'type' field has to be present in the JSON schema which is not required in a valid JSON schema:

Previously generated JSON schema

...
"someEnum" : {
      "description" : "Some enum description",
      "enum" : [ "FIRST_VALUE", "SECOND_VALUE", "THIRD_VALUE" ]
    }
...

Newly generated JSON schema (with commit 04f4bc7)

...
    "someEnum" : {
      "description" : "Some enum description",
      "type" : "string", //this is necessary for proper mapping - but optional by the JSON schema
      "enum" : [ "FIRST_VALUE", "SECOND_VALUE", "THIRD_VALUE" ]
    }
...

• Added tests for the generators which verify that the enums properties are present in v2 and v3 request and response models

Here are some references to the OpenAPI specs:

• v2 Schema properties based on JSON Schema

• v3 Schema properties based on JSON Schema

[ozscheyge]

Thanks for the detailed explanation and links to the schema specs. Made reviewing it a lot easier!

One suggestion: