System.NullReferenceException: 'Object reference not set to an instance of an object.' When using Compressed Static File Middleware?

[Alok Sharma]

Hello, when i am using the compressed middleware i am getting this issue on trying to access embedded files related to #34

info: CompressedStaticFiles.CompressedAlternativeFileProvider[1]
      Sending file. Request file: '/embedbackend/plugins/global/plugins.bundle.css'. Served file: '/embedbackend/plugins/global/plugins.bundle.css.gz'. Original file size: 567386. Served file size: 72449
fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HMHK8J2D283R", Request id "0HMHK8J2D283R:00000009": An unhandled exception was thrown by the application.
      System.NullReferenceException: Object reference not set to an instance of an object.
         at CompressedStaticFiles.CompressedAlternativeFile.Prepare(IContentTypeProvider contentTypeProvider, StaticFileResponseContext staticFileResponseContext)
         at CompressedStaticFiles.CompressedStaticFileMiddleware.<>c__DisplayClass6_0.<InitializeStaticFileOptions>b__0(StaticFileResponseContext context)
         at Microsoft.AspNetCore.StaticFiles.StaticFileContext.ApplyResponseHeaders(Int32 statusCode)
         at Microsoft.AspNetCore.StaticFiles.StaticFileContext.SendAsync()
         at Microsoft.AspNetCore.StaticFiles.StaticFileContext.ServeStaticFile(HttpContext context, RequestDelegate next)
         at Ultra.ImageTools.Services.Middleware.ImageResizerMiddleware.InvokeAsync(HttpContext context) in D:\Projects\Web\dotnet\UltraWeb\Net5\Ultra.WebHost\Ultra.ImageTools\Services\Middleware\ImageResizerMiddleware.cs:line 106
         at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)
[23:57:59 ERR] Connection id "0HMHK8J2D283R", Request id "0HMHK8J2D283R:00000009": An unhandled exception was thrown by the application.
System.NullReferenceException: Object reference not set to an instance of an object.
   at CompressedStaticFiles.CompressedAlternativeFile.Prepare(IContentTypeProvider contentTypeProvider, StaticFileResponseContext staticFileResponseContext)
   at CompressedStaticFiles.CompressedStaticFileMiddleware.<>c__DisplayClass6_0.<InitializeStaticFileOptions>b__0(StaticFileResponseContext context)
   at Microsoft.AspNetCore.StaticFiles.StaticFileContext.ApplyResponseHeaders(Int32 statusCode)
   at Microsoft.AspNetCore.StaticFiles.StaticFileContext.SendAsync()
   at Microsoft.AspNetCore.StaticFiles.StaticFileContext.ServeStaticFile(HttpContext context, RequestDelegate next)   

as i checked the middleware doesn't handle the embedded file headers correctly, hence pass it on to next one so is the problem with this issue. Is there any way to provide it

[Peter]

I have no idea what a embedded file header is, but if you make a pull request with a unit test and a fix i would be happy to merge it and release a new version!

[Alok Sharma]

here embedded file is same as just your other files on system, its just embedded in assembly that's it. I am checking it further, if I get a resolution i will post it here, since you are targeting multiple framework its a bit hard to add these embedded project and test it (i will need to put code instructions for both frameworks to make it work) so it will take some time.

[Alok Sharma]

i found the issue, i will make a PR by tomorrow. i dont think this need a unit test as this only need an additional option to supply virtual paths in that case program will simply switch this line

if (contentTypeProvider.TryGetContentType(staticFileResponseContext.File.PhysicalPath.Remove(
                        staticFileResponseContext.File.PhysicalPath.Length - fileExtension.Length, fileExtension.Length), out var contentType))

this is where null error is happening.

[Alok Sharma]

ok, i have made the PR let me know when its nuget ready :)