Fix missing images everywhere when running locally

[YoshiRulz]

Before/after:

Only has effect in dev environments.

[YoshiRulz]

Build failure is here:

tasvideos/tests/TASVideos.Test/Pages/Wiki/RenderModelTests.cs

Line 18 in d72b31b

_model = new RenderModel(_mockWikiPages, _db, NullLogger<RenderModel>.Instance)

I'm not sure how to get an IHostEnvironment at that point. DI via a constructor parameter prevents the test from running.

[adelikat]

You have to mock it

[Masterjun3]

Is this the right place to insert a dev fallback? It relies on the broken links to be redirected to the wiki endpoint.
Instead, couldn't this be implemented more properly in the options when we add the UseStaticFiles. Maybe by adding a dev FileProvider that uses the regular file provider and doing the fallback logic there?

[adelikat]

I looked and I see no way to do this kind of routing with UseStaticFiles. The best I found is to put some custom middleware, but thsi would mean that we would either always have the dummy images locally (which i do not want, since I have the correct ones) or the middleware would need to do some kind of check if the image exists, which we get for free with this approach. This might be a bit hacky but I don't see a less hacky alternative

[Masterjun3]

@adelikat I mentioned doing it by overriding the StaticFileOptions.FileProvider in the UseStaticFiles call with our own IFileProvider implementation that does this.
Wouldn't that be a good way to do this?

[adelikat]

I would need an example. I tried to do that approach and it seemed impossible

[Masterjun3]

I can give an example in a week if that's okay.

[Masterjun3]

@adelikat I posted my example in PR #2062 .

[adelikat]

Closing in favor of this approach: #2062