[BUG] Parameter with enum is not correctly generated for OAS 3.0 and 3.1

[diei]

Describe the bug

With OAS 2.0 generated JSON of rswag a select box is rendered of enum values for URL parameters. Since I updated to OAS 3 the enum values are not properly processed and no select box is rendered, only an input field. The JSON is generated not as OAS 3 expects it.

Steps to Test or Reproduce

An API with a parameter like described in the following snipped generates a JSON like shown below.

test.rswag_spec.rb:

path '/tests' do
  get 'fetch tests' do
    parameter name: :test_type, in: :query, type: :string, required: false, enum: ['type1', 'type2']

    [...]  
  end
end

Generates:

...
"parameters": [
  {
    "name": "test_type",
    "in": "query",
    "required": false,
    "enum": [
      "type1",
      "type2"
    ],
    "schema": {
      "type": "string"
    }
  }
]
...

Expected behavior

The generated JSON should look like:

...
"parameters": [
  {
    "name": "test_type",
    "in": "query",
    "required": false,
    "schema": {
      "type": "string",
      "enum": [
        "type1",
        "type2"
      ]
    }
  }
]
...

The enum should be in the schema attribute. Then the select box is rendered on the UI page.

Dependency versions

The version of are you using for:

• Rswag: 2.13.0
• RSpec-core: 3.12.2
• Rails: 7.0.8
• Ruby: 3.2.2

Relates to which version of OAS (OpenAPI Specification)

• OAS2
• OAS3
• OAS3.1

[romanblanco]

@diei, would this work for you?

parameter name: :test_type, in: :query, required: false, schema: { type: :array, items: { enum: ['type1', 'type2'] } }

[diei]

@romanblanco, thank you for the hint. It is better but not like before and not like I need it.

The code...

parameter name: :test_type, in: :query, required: false, schema: { type: :array, items: { enum: ['type1', 'type2'] } }

... generates:

"parameters": [{
  "name": "test_type",
  "in": "query",
  "required": false,
  "schema": {
    "type": "array",
    "items": {
      "enum": [
        "type1",
        "type2"
      ]
    }
  }
}]

That is rendered as a multi-select-box. Then I can select several values at the same time which should not be possible, only one or nothing.

I tried it out a bit and figured out that this works:

parameter name: :test_type, in: :query, required: false, schema: { enum: ['type1', 'type2'] }

That definition generates the expected JSON which is rendered as a common select box:

"parameters": [{
  "name": "test_type",
  "in": "query",
  "required": false,
  "schema": {
      "enum": [
        "type1",
        "type2"
      ]
  }
}]

[diei]

During my many tries to find a solution, I noticed that the type: :string is also not correctly transferred to the JSON:

parameter name: :test_type, in: :query, type: :string, required: false, schema: { enum: ['type1', 'type2'] }

Generates this JSON:

"parameters": [{
  "name": "test_type",
  "in": "query",
  "type": "string",
  "required": false,
  "schema": {
      "enum": [
        "type1",
        "type2"
      ]
  }
}]

But the type should be within schema:

"parameters": [{
  "name": "test_type",
  "in": "query",
  "required": false,
  "schema": {
      "type": "string",
      "enum": [
        "type1",
        "type2"
      ]
  }
}]

If I omit the custom schema definition of the parameter the type is added automatically to the schema or I have to move the type: :string from parameter to the custom schema definition:

parameter name: :test_type, in: :query, required: false, schema: { type: :string, enum: ['type1', 'type2'] }