Optional header parameter: Javascript error when not filling the header

[fengelniederhammer]

Q&A (please complete the following information)

• OS: Ubuntu 22.04
• Browser: Firefox
• Version: 122
• Method of installation: org.springdoc:springdoc-openapi-starter-webmvc-ui:2.3.0
• Swagger-UI version: 5.10.3 (at least that's what I infer from springdoc giving me org.webjars:swagger-ui:5.10.3)
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

Example Swagger/OpenAPI definition:

{
  "openapi": "3.0.1",
  "info": {
    "title": "OpenAPI definition",
    "version": "v0"
  },
  "servers": [
    {
      "url": "http://localhost:8080",
      "description": "Generated server url"
    }
  ],
  "paths": {
    "/dummy": {
      "get": {
        "tags": [
          "Dummy-controller"
        ],
        "description": "Dummy",
        "operationId": "dummy_1",
        "parameters": [
          {
            "name": "X-Request-ID",
            "in": "header",
            "description": "a dummy header",
            "required": false,
            "content": {
              "text/plain": {
                "schema": {}
              }
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Dummy",
            "content": {
              "application/json": {
                "schema": {
                  "type": "string"
                }
              }
            }
          }
        }
      }
    }
  }
}

Swagger-UI configuration options:

None that I did myself - maybe Springdoc does something.

Describe the bug you're encountering

To reproduce...

Given an endpoint definition with an optional header parameter (example is above)
When I click on "Try out" and "Execute" of that endpoint without filling the header parameter:
The "Loading" spinner keeps spinning infinitely and there is a JS error in the browser console.

The error from the console as text:

TypeError: i is undefined
    serialize content-serializer.js:12
    parameter_builders_header parameter-builders.js:89
    execute_buildRequest index.js:234
    execute_buildRequest index.js:201
    executeRequest actions.js:454
    systemThunkMiddleware index.js:174
    bindActionCreator Redux
    wrap_actions_executeRequest wrap-actions.js:33
    newAction system.js:175
    wrapWithTryCatch system.js:487
    actions_execute actions.js:501
    systemThunkMiddleware index.js:174
    bindActionCreator Redux
    execute wrap-actions.js:9
    newAction system.js:175
    wrapWithTryCatch system.js:487
    handleValidationResultPass execute.jsx:66
    handleValidationResult execute.jsx:80
    onClick execute.jsx:90
    React 11
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    unstable_runWithPriority scheduler.production.min.js:18
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system.js:490:16

Expected behavior

The request should be sent.

Screenshots

Additional context or thoughts

[char0n]

Hi everybody,

@glowcloud as discussed please test this also for OpenAPI 2.0, so that we know how SwaggerUI behaves.

[glowcloud]

Looking at OpenAPI 2.0, if we somehow get an undefined value for path, we'll replace the parameter in path with undefined, ex.: https://petstore.swagger.io/v2/pet/undefined/uploadImage.

For body, it looks like we'll also have undefined, from buildRequest test:

{
  url: 'http://swagger.io/me',
  credentials: 'same-origin',
  headers: {},
  method: 'POST',
  body: undefined
}

It's because we don't check if we have undefined for them:
https://github.com/swagger-api/swagger-js/blob/0fa7806772afc0ab5b4e3428468756e5e07f2a57/src/execute/swagger2/parameter-builders.js#L13-L15
and
https://github.com/swagger-api/swagger-js/blob/0fa7806772afc0ab5b4e3428468756e5e07f2a57/src/execute/swagger2/parameter-builders.js#L38-L40

We might also want to change the check in formDataBuilder
https://github.com/swagger-api/swagger-js/blob/0fa7806772afc0ab5b4e3428468756e5e07f2a57/src/execute/swagger2/parameter-builders.js#L19
to check if we have undefined, as right now, if we have allowEmptyValue: true but we don't select that option in Swagger UI, ex:

we'll send an empty value anyway:

curl -X 'POST' \
  'https://petstore.swagger.io/v2/pet/undefined/uploadImage' \
  -H 'accept: application/json' \
  -H 'Content-Type: multipart/form-data' \
  -F 'additionalMetadata=' \
  -F 'file='

[char0n]

Fixes to OpenAPI 3 definitions addressed upstream in swagger-client@3.26.1.

[char0n]

This is going to be available in next SwaggerUI release. Please reopen if it's still manifesting in new release.

[char0n]

Released as https://github.com/swagger-api/swagger-ui/releases/tag/v5.12.2