Selecting "--" choice in dropdown throws error

[dalbani]

Q&A (please complete the following information)

• OS: Ubuntu 18.04
• Browser: Chrome
• Version: 75
• Method of installation: Docker
• Swagger-UI version: 3.23.0
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

OpenAPI definition:

openapi: "3.0.0"
info:
  title: Testcase API
  version: 2.0.0
paths:
  '/endpoint':
    get:
      parameters:
        - name: type
          in: query
          example: fruit
          schema:
            type: string
            enum:
              - fruit
              - vegetable
              - drink
      responses:
        '200':
          description: 200 response

Describe the bug you're encountering

Selecting the -- choice in a dropdown menu throws an error about not being able to render the component.

To reproduce...

Steps to reproduce the behavior:

1. Go to the Swagger Editor
2. Copy/paste the YAML definition
3. Select the -- choice in the dropdown for the type parameter.
4. See following error:
   😱 Could not render this component, see the console.

Expected behavior

No error should be reported to the user, the dropdown should support being set to --.

Screenshots

Additional context or thoughts

The issue has apparently to do with code at https://github.com/swagger-api/swagger-ui/blob/master/src/core/components/layout-utils.jsx#L187.

The value of this.state.value is null for the -- select option, thus failing when trying to access the .toJS property.

Or am I simply missing something obvious in my OpenAPI definition?!?

[shockey]

@dalbani, just curious, is this working for you in older versions (e.g. 3.22.x)?

Edit: just confirmed it for myself, v3.22.3 doesn't have this issue. Tagging as a regression!

[dalbani]

Oh, indeed, you're right. I didn't check from which version the issue appeared.

[shockey]

Also, I'm curious -- did you have to do any work to get the stack trace in your screenshot (e.g. loading source maps), or was it there by default?

[dalbani]

No I didn't have to do anything special. I was using the Docker image by the way.
Do you mean this debug information shouldn't have been there in the first place?

[hkosova]

@shockey fyi this issue affects OAS2 too:
https://petstore.swagger.io/?url=https://vocadb.net/swagger/docs/v1#/ActivityEntryApi/ActivityEntryApi_GetList

[shockey]

Do you mean this debug information shouldn't have been there in the first place?

@dalbani not at all, I was just happy to see our source maps working for you 😄

[shockey]

Fixed!

Will ship this tonight. Thanks for the report @dalbani!