SwaggerUI combo for api definitions is cached / not refreshed

[WolfgangHG]

I have a service that follows this blog post to add versioning to my rest api: the controllers are placed in directories "v1" and "v2", and SwaggerUI should display the different versions in the "Select a definition" combo in the upper right corner.

This did not seem to work for me - a new version did not appear in the combo. After hours of searching, I found that it is an issue of browser caching (happens at least with firefox) - a simple "Ctrl+F5" would have saved me a lot of time.

Attached is an updated version of the blog post sample from https://github.com/gavilanch/ASPNETCoreSwaggerVersioning (updated to recent Swashbuckle versions):
ASPNETCoreSwaggerVersioning.zip

To reproduce:

• start the project using the launch profile "WebApiSwaggerVersion", which should open your default browser and SwaggerUI.
  

• modify those lines and change the "name" argument" - I added an "X".

  app.UseSwaggerUI(config =>
  {
      config.SwaggerEndpoint("/swagger/v1/swagger.json", "X MoviesAPI v1");
      config.SwaggerEndpoint("/swagger/v2/swagger.json", "X MoviesAPI v2");
  });

• launch the project again. The combo should still show the old names. A "Ctrl+F5" should fix it.

If found #3336 which is about cache headers for SwaggerUI, but it does not seem to affect my sample.

Is there anything that can be done in my app about this?

[martincostello]

From a quick look at the code, not without adding some custom code to try and manually set the cache headers on the response for the index page and/or endpoint resource to cache-bust it.

We should probably build-in similar caching for the endpoint URLs response as we do for all the static files: #3710

[WolfgangHG]

OK, I learned that i have to disable caching in Firefox developer, otherwise the problem did not happen whenever I reloaded the page with developer tools open ;-).

I cannot make sense of the output and don't find the place where the list of API definitions is populated. So I attach screenshots of firefox and edge developer tools, and hopefully you can tell me where to look at.
Edge:

Firefox:

Is the combo coming from the call to "index.html" in the first step? If yes: there is a long term caching:

[martincostello]

Could you please provide the code for what you're doing above as a GitHub repository (not a ZIP) and I'll take a look.

[WolfgangHG]

@martincostello Sure: https://github.com/WolfgangHG/Swashbuckle_Discussion3709/

The relevant code snippet is here:
https://github.com/WolfgangHG/Swashbuckle_Discussion3709/blob/08adbcb8406a724a0647aab5596a78f1cab66fe5/WebApiSwaggerVersion/Startup.cs#L69-L74

Start the project (using profile "WebApiSwaggerVersion"), then close the browser, make a change to the second argument name of config.SwaggerEndpoint and start the project again. The issue should happen.

[martincostello]

Thanks. Turns out this wasn't anything to do with the document URLs endpoint as they were just rendered in the JavaScript for the UI page, but the caching behaviour had various bugs in it. #3772 should fix it.

[WolfgangHG]

Yes, it works now! Many thanks for the great support.

Is the first fix attempt by the AI relevant at all or is this something that should be rolled back ;-)?

[martincostello]

No, Copilot just applied some existing code to an additional place. That existing code wasn't written by Copilot.