[BUG] [typescript-axios] nullable: true is not respected with enum

[Naktibalda]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

We added a nullable enum attribute to request body of a function in our API. OpenAPI generator generates typescript-axios client code which omits information that the attribute is nullable, so the client must provide enum value which is undesirable, because we want to keep using null for that attribute by default and use enums only in special cases required by a new feature.

OpenApiSpecification:

components:
  schemas:
    SchemaName:
      type: object
      properties:
        field:
          type: string
          nullable: true
          enum: &a5
          - foo
          - bar
          - baz

Generated code:

interface SchemaName {
    /**
     * 
     * @type {string}
     * @memberof SchemaName
     */
    'objectType': FieldEnum;
}

What we actually want:

interface SchemaName {
    /**
     * 
     * @type {string}
     * @memberof SchemaName
     */
    'objectType': FieldEnum | null;
}

openapi-generator version

7.1.0

OpenAPI declaration file content or url

Generation Details

npx openapi-generator-cli generate --generator-key projectname

Related issues/PRs

• Similar typescript-fetch issue: [BUG] [typescript-fetch] nullable: true is not respected with enum #7745
• PR which introduced support for enums: Generate and use enum types in parameters for typescript-axios #13438

Suggest a fix

I think that isNullable condition is missing inside #isEnum condition in

'{{baseName}}'{{^required}}?{{/required}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{#isNullable}} | null{{/isNullable}}{{/isEnum}};

at

openapi-generator/modules/openapi-generator/src/main/resources/typescript-axios/modelGeneric.mustache

Line 20 in 8911740

'{{baseName}}'{{^required}}?{{/required}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{#isNullable}} | null{{/isNullable}}{{/isEnum}};

[Naktibalda]

It seems that I accidentally solved my problem by creating a reusable enum component instead of inlining it in different params components.

components:
  schemas:
    FieldEnum:
      type: string
      nullable: true
      enum:
      - foo
      - bar
      - baz

    SchemaName:
      field:
        $ref: "#/components/schemas/FieldEnum"

Generates correct code:

  'field': FieldEnum | null;