public class Startup {

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // NOTE: PRODUCTION Ensure this is the same path that is specified in your webpack output
            services.AddSpaStaticFiles(opt => opt.RootPath = "ClientApp/dist");
            services.AddControllers();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
	    // optional base path for IIS virtual app/directory
	    app.UsePathBase("/optionalpath");
            
	    // PRODUCTION uses webpack static files
            app.UseSpaStaticFiles();

            // Routing
            app.UseRouting();
            app.UserAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();

                endpoints.MapToVueCliProxy(
                    "{*path}",
                    new SpaOptions { SourcePath = "ClientApp" },
                    npmScript: (System.Diagnostics.Debugger.IsAttached) ? "serve" : null,
                    regex: "Compiled successfully",
                    forceKill: true,
		    wsl: false // Set to true if you are using WSL on windows. For other operating systems it will be ignored
                    );
            });
        }
    }

    using VueCliMiddleware;

    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        public virtual void ConfigureServices(IServiceCollection services)
        {
           services.AddMvc(); // etc
           
           // Need to register ISpaStaticFileProvider for UseSpaStaticFiles middleware to work
           services.AddSpaStaticFiles(configuration => { configuration.RootPath = "ClientApp/dist"; });
        }

        public virtual void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
           // your config opts...
		   // optional basepath
		   // app.UsePathBase("/myapp");

           // add static files from SPA (/dist)
          app.UseSpaStaticFiles();

          app.UseMvc(routes => /* configure*/ );

          app.UseSpa(spa =>
            {
                spa.Options.SourcePath = "ClientApp";
#if DEBUG
                if (env.IsDevelopment())
                {
                    spa.UseVueCli(npmScript: "serve", port: 8080); // optional port
                }
#endif
            });
        }
    }