public void ConfigureRouting_ConfiguresOptionsProperly() { // Arrange var services = new ServiceCollection().AddOptions(); // Act services.ConfigureRouting(options => options.ConstraintMap.Add("foo", typeof(TestRouteConstraint))); var serviceProvider = services.BuildServiceProvider(); // Assert var accessor = serviceProvider.GetRequiredService<IOptions<RouteOptions>>(); Assert.Equal("TestRouteConstraint", accessor.Options.ConstraintMap["foo"].Name); }