Unable to Generate GO clients when schema has enums on it

[arturoguedez]

Description

When attempting to generate GO clients from a schema that uses Enums, it fails with error :

15:58:49.856 [main] INFO  i.s.c.v.g.t.AbstractTypeScriptClientCodegen - Template folder: null
15:58:49.856 [main] INFO  i.s.c.v.g.t.AbstractTypeScriptClientCodegen - Template engine: io.swagger.codegen.v3.templates.HandlebarTemplateEngine@e98770d
15:58:49.877 [Thread-0] INFO  i.s.c.v.g.t.AbstractTypeScriptClientCodegen - Template folder: null
15:58:49.878 [Thread-0] INFO  i.s.c.v.g.t.AbstractTypeScriptClientCodegen - Template engine: io.swagger.codegen.v3.templates.HandlebarTemplateEngine@53ba3063
Exception in thread "Thread-0" java.lang.RuntimeException: Could not process model 'ASchemaName'.Please make sure that your schema is correct!
	at io.swagger.codegen.v3.DefaultGenerator.generateModels(DefaultGenerator.java:391)
	at io.swagger.codegen.v3.DefaultGenerator.generate(DefaultGenerator.java:793)
	at io.swagger.codegen.v3.cli.cmd.Generate.run(Generate.java:388)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException: Cannot invoke "String.equals(Object)" because "codegenModel.dataType" is null
	at io.swagger.codegen.v3.generators.DefaultCodegenConfig.fromModel(DefaultCodegenConfig.java:1466)
	at io.swagger.codegen.v3.generators.go.AbstractGoCodegen.fromModel(AbstractGoCodegen.java:565)
	at io.swagger.codegen.v3.DefaultGenerator.processModels(DefaultGenerator.java:1068)
	at io.swagger.codegen.v3.DefaultGenerator.generateModels(DefaultGenerator.java:380)
	... 3 more

Swagger-codegen version

Whichever version is in the docker image swaggerapi/swagger-codegen-cli-v3. 3.0.59?

Swagger declaration file content or url

openapi: 3.1.0

components:
  schemas:
    ASchemaName:
      type: string
      enum: [value1,value2,value3]
   

Command line used for generation

This works
docker run --rm -v ${PWD}:/local swaggerapi/swagger-codegen-cli-v3 generate -i /local/simplest.yml -l javascript -o /local/out/go

This does not
docker run --rm -v ${PWD}:/local swaggerapi/swagger-codegen-cli-v3 generate -i /local/simplest.yml -l go -o /local/out/go

Steps to reproduce

docker run --rm -v ${PWD}:/local swaggerapi/swagger-codegen-cli-v3 generate -i /local/simplest.yml -l go -o /local/out/go

Related issues/PRs

Unknown

Suggest a fix/enhancement

[kunwooy]

Having same issue here. Any updates?