enum support for golang in swagger-codegen

[jeetcontext]

Description

I am trying to generate sdk for golang with respect to a json file. It is not able to generate the enum type.

Swagger-codegen version

Version 2.2.2-snapshot

Swagger declaration file content or url

"catalog_type": {
"description": "Type of the catalog",
"enum": [
"CATALOG_A",
"CATALOG_B"
],
"title": "Catalog type",
"type": "string"
}
This is part of json file.

Command line used for generation

After doing the mvn build, used

Java -jar modules/swagger-codegen-cli/target/swagger-codegen-cli/target/swagger-codegen-cli.jar generate -i test.json -o ./gosdk

Steps to reproduce

Related issues

There is another dev going on with go-swagger which supports enum.

Suggest a Fix

May be the template file and the GoClientCodegen file needs to be updated for complex json.

[jeetcontext]

I checked with petstore as well, It is not generating the enum inside pet object.

[taxpon]

@jeetcontext @wing328 I am interested in working on this issue. go-swagger is providing Validate method and validating enum value inside it. I am now planning to implement similar methods in swagger-codegen, is it OK?

[wing328]

@taxpon do you mean adding go-swagger as a dependency to the auto-generated Go API client?

For enum support in Go, I suggest we do it in the 2.3.0 branch in which @antihax has made a lot of enhancements to the Go API client, e.g. proper support of optional parameters.

[antihax]

Go does not support enum, so i think it is as simple as validating input is one of the enum elements as @jeetcontext suggest. But, to throw a wrench in the gears a bit...

5.20. enum
The value of this keyword MUST be an array. This array SHOULD have at least one element. Elements in the array SHOULD be unique.
Elements in the array MAY be of any type, including null.

We know Go also does not allow nil data types, so this may be better using interface{} or pointers.

[taxpon]

@wing328 I intended not to add go-swagger as a dependency but to update mustache template in swagger-codegen so that it provides methods for validations (like go-swagger).

[vpolouchkine]

Just ran into this. FWIW Go "enums" are typically done like this:

type MyEnum string

const (
	Foo MyEnum = "foo"
	Bar MyEnum = "bar"
)

[wing328]

@vpolouchkine thanks for sharing.

Has anyone started working on this yet? If yes, please kindly share the progress. Thanks.

[marcusljx]

I wouldn't mind helping out with this. It seems trivial to generate enums in golang (basically a type alias). But as I'm new to swagger-codegen, could someone please let me know where I can read the logic of the swagger-spec java parser?

Specifically, I'm not sure what fields are in the hash used with the mustache templates.