OneOf not generating all options

[thiagonuic]

Hi, thanks for providing such a library for the community. We are using redoc in our code and we found a potential issue in the generated JSON and we traced it down to this library. I compared the OpenAPI doc we generate using the https://editor.swagger.io/ to see if we were diverging from what is expected and apparently it is a bug here in openapi-sampler.

It happens when we use the OneOf and it generates the wrong output. To best exemplify, I created a test for the object.spec.js file.

Please let me know what you think.

  it('should generate both items of oneOf', () => {
    res = sampleObject({
      'type': 'object',
      'properties': {
        'my_obj': {
          'type': 'object',
          'properties': {
            'elements': {
              'items': {
                'oneOf': [
                  {
                    'type': 'object',
                    'properties': {
                      'name': {
                        'type': 'string',
                        'description': '',
                        'enum': [
                          'obj_a'
                        ]
                      }
                    },
                    'title': 'obj_a',
                    'required': [
                      'name'
                    ]
                  },
                  {
                    'type': 'object',
                    'properties': {
                      'name': {
                        'type': 'string',
                        'description': '',
                        'enum': [
                          'obj_b'
                        ]
                      }
                    },
                    'title': 'obj_b',
                    'required': [
                      'name'
                    ]
                  }
                ]
              },
              'type': 'array',
              'minItems': 2,
              'maxItems': 2,
              'uniqueItems': true
            }
          },
          'title': '',
          'required': [
            'elements'
          ]
        }
      },
      'required': [
        'my_obj'
      ]
    })

    expect(res).deep.equal({
      'my_obj': {
        'elements': [
          {
            'name': 'obj_a'
          },
          {
            'name': 'obj_b'
          }
        ]
      }
    })
  });