Compiled files return with wrong mime type

[SamuelJohnsonMedia]

The compiled SCSS file is returned as text/plain and not text/css; charset=UTF-8 which fails to be imported if you are using strict mime type security headers.

In ConfigureServices I have:

        services.AddWebOptimizer( pipeline =>
        {
          pipeline.AddScssBundle( "/all.css", "site.scss" );
        } );

Chromium console log:

Refused to apply style from 'https://localhost:44332/css/all.css' because its MIME type ('text/plain') is not a supported stylesheet MIME type, and strict MIME checking is enabled.

This is strange as I can see that the pipeline is being set properly:

WebOptimizer.Sass/src/PipelineExtensions.cs

Line 45 in 3e7a919

return pipeline.AddBundle(route, "text/css; charset=UTF-8", sourceFiles)