Last-modified response header date-time wrongly formatted in Response headers box

Q&A

• OS: macOS Monterey 12.4
• Browser: Chrome
• Version: 105.0.5195.102 (arm64)
• Method of installation: docker
• Swagger-UI version: 4.14.0
• OpenAPI version: OpenAPI 3.0.0

Content & configuration

Example Swagger/OpenAPI definition:

(...)
  200:
     description: (...)
     headers:
        Last-Modified:
           description: (...)
           schema:
              type: string
              format: HTTP-date
              example: Fri, 27 Sep 2019 11:00:00 GMT
(...)  

Swagger-UI is in it's default configuration.

Describe the bug you're encountering

When testing an endpoint that is returning http Last-modified header, in the swagger Response headers box, instead of having them displayed raw as they are returned from the server, headers are lowercased (not an issue) and Last-modified is reformatted in a way that it no longer conforms to HTTP-date format (RFC2616)

Sending it in this format in If-Modified-Since header may then result in ignoring it as that's what http protocol tells to do (RFC7232).

To reproduce...

Nothing special:

1. Go to swagger-ui
2. Click on Try it out and Execute request returning Last-modified
3. Scroll down to Response headers
4. See how Last-modified is wrongly formatted

Expected behavior

Instead of Fri,20 Jul 2018 20:23:07 GMT, it should be Fri, 20 Jul 2018 20:23:07 GMT

Screenshots

Server response headers:

Swagger response headers box:

Reproduce the issue in Swagger UI by executing an endpoint that returns a Last-Modified response header and inspect the Response headers box. Confirm that the displayed value preserves the HTTP-date spacing, including the space after the comma, and verify the result against the reported expected value.