Merge pull request #126 from BillWagner/csharp7-on-mvcapp

C# 7 language feature updates

src/Web/WebMVC/Controllers/AccountController.cs

@@ -11,16 +11,11 @@ namespace Microsoft.eShopOnContainers.WebMVC.Controllers
     public class AccountController : Controller
     {
         private readonly IIdentityParser<ApplicationUser> _identityParser;
-        public AccountController(IIdentityParser<ApplicationUser> identityParser)
+        public AccountController(IIdentityParser<ApplicationUser> identityParser) => 
-        {
             _identityParser = identityParser;
-        }
-
-        public ActionResult Index()
-        {
-            return View();
-        }
 
+        public ActionResult Index() => View();
+        
         [Authorize]
         public IActionResult SignIn(string returnUrl)
         {

src/Web/WebMVC/Controllers/CatalogController.cs

@@ -14,10 +14,8 @@ namespace Microsoft.eShopOnContainers.WebMVC.Controllers
     {
         private ICatalogService _catalogSvc;
 
-        public CatalogController(ICatalogService catalogSvc)
+        public CatalogController(ICatalogService catalogSvc) => 
-        {
             _catalogSvc = catalogSvc;
-        }
 
         public async Task<IActionResult> Index(int? BrandFilterApplied, int? TypesFilterApplied, int? page)
         {
@@ -35,7 +33,7 @@ namespace Microsoft.eShopOnContainers.WebMVC.Controllers
                     ActualPage = page ?? 0,
                     ItemsPerPage = catalog.Data.Count,
                     TotalItems = catalog.Count, 
-                    TotalPages = int.Parse(Math.Ceiling(((decimal)catalog.Count / itemsPage)).ToString())
+                    TotalPages = (int)Math.Ceiling(((decimal)catalog.Count / itemsPage))
                 }
             };
 
@@ -45,10 +43,7 @@ namespace Microsoft.eShopOnContainers.WebMVC.Controllers
             return View(vm);
         }
 
-        public IActionResult Error()
+        public IActionResult Error() => View();
-        {
-            return View();
-        }
     }
 }
 

src/Web/WebMVC/Extensions/HttpClientExtensions.cs

@@ -11,20 +11,14 @@ namespace Microsoft.eShopOnContainers.WebMVC.Extensions
 {
     public static class HttpClientExtensions
     {
-        public static void SetBasicAuthentication(this HttpClient client, string userName, string password)
+        public static void SetBasicAuthentication(this HttpClient client, string userName, string password) =>
-        {
             client.DefaultRequestHeaders.Authorization = new BasicAuthenticationHeaderValue(userName, password);
-        }
 
-        public static void SetToken(this HttpClient client, string scheme, string token)
+        public static void SetToken(this HttpClient client, string scheme, string token) =>
-        {
             client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(scheme, token);
-        }
 
-        public static void SetBearerToken(this HttpClient client, string token)
+        public static void SetBearerToken(this HttpClient client, string token) =>
-        {
             client.SetToken(JwtConstants.TokenType, token);
-        }
     }
 
     public class BasicAuthenticationHeaderValue : AuthenticationHeaderValue

src/Web/WebMVC/Extensions/SessionExtensions.cs

@@ -8,10 +8,8 @@ using System.Threading.Tasks;
 
 public static class SessionExtensions
 {
-    public static void SetObject(this ISession session, string key, object value)
+    public static void SetObject(this ISession session, string key, object value) =>
-    {
         session.SetString(key, JsonConvert.SerializeObject(value));
-    }
 
     public static T GetObject<T>(this ISession session, string key)
     {

src/Web/WebMVC/Services/BasketService.cs

@@ -33,16 +33,14 @@ namespace Microsoft.eShopOnContainers.WebMVC.Services
 
             _apiClient.Inst.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
 
-            var basketUrl = $"{_remoteServiceBaseUrl}/{user.Id.ToString()}";
+            var basketUrl = $"{_remoteServiceBaseUrl}/{user.Id}";
             var dataString = await _apiClient.GetStringAsync(basketUrl);
-            var response = JsonConvert.DeserializeObject<Basket>(dataString);
+            // Use the ?? Null conditional operator to simplify the initialization of response
-            if (response == null)
+            var response = JsonConvert.DeserializeObject<Basket>(dataString) ?? 
-            {
+                new Basket()
-                response = new Basket()
                 {
                     BuyerId = user.Id
                 };
-            }
 
             return response;
         }
@@ -67,9 +65,12 @@ namespace Microsoft.eShopOnContainers.WebMVC.Services
 
             basket.Items.ForEach(x =>
             {
-                var quantity = quantities.Where(y => y.Key == x.Id).FirstOrDefault();
+                // Simplify this logic by using the
-                if (quantities.Where(y => y.Key == x.Id).Count() > 0)
+                // new out variable initializer.
-                    x.Quantity = quantity.Value;
+                if (quantities.TryGetValue(x.Id, out var quantity))
+                {
+                    x.Quantity = quantity;
+                }
             });
 
             return basket;
@@ -119,7 +120,7 @@ namespace Microsoft.eShopOnContainers.WebMVC.Services
             var token = await context.Authentication.GetTokenAsync("access_token");
 
             _apiClient.Inst.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
-            var basketUrl = $"{_remoteServiceBaseUrl}/{user.Id.ToString()}";
+            var basketUrl = $"{_remoteServiceBaseUrl}/{user.Id}";
             var response = await _apiClient.DeleteAsync(basketUrl);
             
             //CCE: response status code...

src/Web/WebMVC/Services/CatalogService.cs

@@ -61,8 +61,11 @@ namespace Microsoft.eShopOnContainers.WebMVC.Services
             JArray brands = JArray.Parse(dataString);
             foreach (JObject brand in brands.Children<JObject>())
             {
-                dynamic item = brand;
+                items.Add(new SelectListItem()
-                items.Add(new SelectListItem() { Value = item.id, Text = item.brand });
+                {
+                    Value = brand.Value<string>("id"),
+                    Text = brand.Value<string>("brand")
+                });
             }
 
             return items;
@@ -79,10 +82,12 @@ namespace Microsoft.eShopOnContainers.WebMVC.Services
             JArray brands = JArray.Parse(dataString);
             foreach (JObject brand in brands.Children<JObject>())
             {
-                dynamic item = brand;
+                items.Add(new SelectListItem()
-                items.Add(new SelectListItem() { Value = item.id, Text = item.type });
+                {
+                    Value = brand.Value<string>("id"),
+                    Text = brand.Value<string>("type")
+                });
             }
-
             return items;
         }
     }

src/Web/WebMVC/Services/IdentityParser.cs

@@ -12,26 +12,31 @@ namespace Microsoft.eShopOnContainers.WebMVC.Services
     {
         public ApplicationUser Parse(IPrincipal principal)
         {
-            var user = new ApplicationUser();
+            // Pattern matching 'is' expression
-            var claims = (ClaimsPrincipal)principal;
+            // assigns "claims" if "principal" is a "ClaimsPrincipal"
+            if (principal is ClaimsPrincipal claims)
+            {
+                return new ApplicationUser
+                {
 
-            user.CardHolderName = (claims.Claims.Where(x => x.Type == "card_holder").Count() > 0) ? claims.Claims.First(x => x.Type == "card_holder").Value : "";
+                    CardHolderName = claims.Claims.FirstOrDefault(x => x.Type == "card_holder")?.Value ?? "",
-            user.CardNumber = (claims.Claims.Where(x => x.Type == "card_number").Count() > 0) ? claims.Claims.First(x => x.Type == "card_number").Value : "";
+                    CardNumber = claims.Claims.FirstOrDefault(x => x.Type == "card_number")?.Value ?? "",
-            user.Expiration = (claims.Claims.Where(x => x.Type == "card_expiration").Count() > 0) ? claims.Claims.First(x => x.Type == "card_expiration").Value : "";
+                    Expiration = claims.Claims.FirstOrDefault(x => x.Type == "card_expiration")?.Value ?? "",
-            user.CardType = (claims.Claims.Where(x => x.Type == "missing").Count() > 0) ? int.Parse(claims.Claims.First(x => x.Type == "missing").Value) : 0;
+                    CardType = int.Parse(claims.Claims.FirstOrDefault(x => x.Type == "missing")?.Value ?? "0"),
-            user.City = (claims.Claims.Where(x => x.Type == "address_city").Count() > 0) ? claims.Claims.First(x => x.Type == "address_city").Value : "";
+                    City = claims.Claims.FirstOrDefault(x => x.Type == "address_city")?.Value ?? "",
-            user.Country = (claims.Claims.Where(x => x.Type == "address_country").Count() > 0) ? claims.Claims.First(x => x.Type == "address_country").Value : "";
+                    Country = claims.Claims.FirstOrDefault(x => x.Type == "address_country")?.Value ?? "",
-            user.Email = (claims.Claims.Where(x => x.Type == "email").Count() > 0) ? claims.Claims.First(x => x.Type == "email").Value : "";
+                    Email = claims.Claims.FirstOrDefault(x => x.Type == "email")?.Value ?? "",
-            user.Id = (claims.Claims.Where(x => x.Type == "sub").Count() > 0) ? claims.Claims.First(x => x.Type == "sub").Value : "";
+                    Id = claims.Claims.FirstOrDefault(x => x.Type == "sub")?.Value ?? "",
-            user.LastName = (claims.Claims.Where(x => x.Type == "last_name").Count() > 0) ? claims.Claims.First(x => x.Type == "last_name").Value : "";
+                    LastName = claims.Claims.FirstOrDefault(x => x.Type == "last_name")?.Value ?? "",
-            user.Name = (claims.Claims.Where(x => x.Type == "name").Count() > 0) ? claims.Claims.First(x => x.Type == "name").Value : "";
+                    Name = claims.Claims.FirstOrDefault(x => x.Type == "name")?.Value ?? "",
-            user.PhoneNumber = (claims.Claims.Where(x => x.Type == "phone_number").Count() > 0) ? claims.Claims.First(x => x.Type == "phone_number").Value : "";
+                    PhoneNumber = claims.Claims.FirstOrDefault(x => x.Type == "phone_number")?.Value ?? "",
-            user.SecurityNumber = (claims.Claims.Where(x => x.Type == "card_security_number").Count() > 0) ? claims.Claims.First(x => x.Type == "card_security_number").Value : "";
+                    SecurityNumber = claims.Claims.FirstOrDefault(x => x.Type == "card_security_number")?.Value ?? "",
-            user.State = (claims.Claims.Where(x => x.Type == "address_state").Count() > 0) ? claims.Claims.First(x => x.Type == "address_state").Value : "";
+                    State = claims.Claims.FirstOrDefault(x => x.Type == "address_state")?.Value ?? "",
-            user.Street = (claims.Claims.Where(x => x.Type == "address_street").Count() > 0) ? claims.Claims.First(x => x.Type == "address_street").Value : "";
+                    Street = claims.Claims.FirstOrDefault(x => x.Type == "address_street")?.Value ?? "",
-            user.ZipCode = (claims.Claims.Where(x => x.Type == "address_zip_code").Count() > 0) ? claims.Claims.First(x => x.Type == "address_zip_code").Value : "";
+                    ZipCode = claims.Claims.FirstOrDefault(x => x.Type == "address_zip_code")?.Value ?? ""
-
+                };
-            return user;
+            }
+            throw new ArgumentException(message: "The principal must be a ClaimsPrincipal", paramName: nameof(principal));
         }
     }
 }

src/Web/WebMVC/Services/Utilities/HttpApiClient.cs

@@ -16,30 +16,18 @@ namespace WebMVC.Services.Utilities
             _client = new HttpClient();
             _logger = new LoggerFactory().CreateLogger(nameof(HttpApiClientWrapper));
         }
+        
+        public Task<string> GetStringAsync(string uri) =>
+            _client.GetStringAsync(uri);
 
-        public async Task<string> GetStringAsync(string uri)
+        public Task<HttpResponseMessage> PostAsync<T>(string uri, T item)
-        {
-            return await HttpInvoker(async () =>
-                await _client.GetStringAsync(uri));
-        }
-
-        public async Task<HttpResponseMessage> PostAsync<T>(string uri, T item)
         {
             var contentString = new StringContent(JsonConvert.SerializeObject(item), System.Text.Encoding.UTF8, "application/json");
-            return await HttpInvoker(async () =>
+            return _client.PostAsync(uri, contentString);
-                    await _client.PostAsync(uri, contentString));
         }
 
-        public async Task<HttpResponseMessage> DeleteAsync(string uri)
+        public Task<HttpResponseMessage> DeleteAsync(string uri) =>
-        {
+            _client.DeleteAsync(uri);
-            return await HttpInvoker(async () =>
-                await _client.DeleteAsync(uri));
-        }
-
-        private async Task<T> HttpInvoker<T>(Func<Task<T>> action)
-        {
-            return await action();
-        }
     }
 }
 

src/Web/WebMVC/Services/Utilities/HttpApiClientWrapper.cs

@@ -24,76 +24,74 @@ namespace WebMVC.Services.Utilities
                 CreateRetryPolicy(),
                 CreateCircuitBreakerPolicy()
             );
-        }       
-
-        private Policy CreateCircuitBreakerPolicy()
-        {
-            return Policy
-                .Handle<HttpRequestException>()
-                .CircuitBreakerAsync(
-                    // number of exceptions before breaking circuit
-                    3, 
-                    // time circuit opened before retry
-                    TimeSpan.FromMinutes(1), 
-                    (exception, duration) => {
-                        // on circuit opened
-                        _logger.LogTrace("Circuit breaker opened");
-                    }, 
-                    () => {
-                        // on circuit closed
-                        _logger.LogTrace("Circuit breaker reset");
-                    }
-                );
         }
 
-        private Policy CreateRetryPolicy()
+        private Policy CreateCircuitBreakerPolicy() =>
-        {
+            Policy.Handle<HttpRequestException>()
-            return Policy
+            .CircuitBreakerAsync(
-                .Handle<HttpRequestException>()
+                // number of exceptions before breaking circuit
-                .WaitAndRetryAsync(
+                3,
-                    // number of retries
+                // time circuit opened before retry
-                    3, 
+                TimeSpan.FromMinutes(1),
-                    // exponential backofff
+                (exception, duration) =>
-                    retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)),
+                {
-                    // on retry
+                    // on circuit opened
-                    (exception, timeSpan, retryCount, context) =>  
+                    _logger.LogTrace("Circuit breaker opened");
-                    {
+                },
-                        _logger.LogTrace($"Retry {retryCount} " +
+                () =>
-                            $"of {context.PolicyKey} " +
+                {
-                            $"at {context.ExecutionKey}, " +
+                    // on circuit closed
-                            $"due to: {exception}.");
+                    _logger.LogTrace("Circuit breaker reset");
-                 });
+                }
-        }
+            );
 
-        public async Task<string> GetStringAsync(string uri)
+        private Policy CreateRetryPolicy() =>
-        {
+            Policy.Handle<HttpRequestException>()
-            return await HttpInvoker(async () => 
+            .WaitAndRetryAsync(
-                await _client.GetStringAsync(uri));
+                // number of retries
-        }
+                3, 
+                // exponential backofff
+                retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)),
+                // on retry
+                (exception, timeSpan, retryCount, context) =>  
+                {
+                    _logger.LogTrace($"Retry {retryCount} " +
+                        $"of {context.PolicyKey} " +
+                        $"at {context.ExecutionKey}, " +
+                        $"due to: {exception}.");
+                }
+            );
 
-        public async Task<HttpResponseMessage> PostAsync<T>(string uri, T item)
+        // Notice that these (and other methods below) are Task
-        {
+        // returning asynchronous methods. But, they do not
+        // have the 'async' modifier, and do not contain
+        // any 'await statements. In each of these methods,
+        // the only asynchronous call is the last (or only)
+        // statement of the method. In those instances,
+        // a Task returning method that does not use the 
+        // async modifier is preferred. The compiler generates
+        // synchronous code for this method, but returns the 
+        // task from the underlying asynchronous method. The
+        // generated code does not contain the state machine
+        // generated for asynchronous methods.
+        public Task<string> GetStringAsync(string uri) =>
+            HttpInvoker(() => _client.GetStringAsync(uri));
+
+        public Task<HttpResponseMessage> PostAsync<T>(string uri, T item) =>
             // a new StringContent must be created for each retry 
             // as it is disposed after each call
-            return await HttpInvoker(async () =>
+            HttpInvoker(() =>_client.PostAsync(uri, 
-                    await _client.PostAsync(uri, 
+                new StringContent(JsonConvert.SerializeObject(item), 
-                        new StringContent(JsonConvert.SerializeObject(item), 
+                System.Text.Encoding.UTF8, "application/json")));
-                        System.Text.Encoding.UTF8, "application/json")));
-        }
 
-        public async Task<HttpResponseMessage> DeleteAsync(string uri)
+        public Task<HttpResponseMessage> DeleteAsync(string uri) =>
-        {
+            HttpInvoker(() => _client.DeleteAsync(uri));
-            return await HttpInvoker(async () =>
-                await _client.DeleteAsync(uri));
-        }
 
-        private async Task<T> HttpInvoker<T>(Func<Task<T>> action)
+
-        {
+        private Task<T> HttpInvoker<T>(Func<Task<T>> action) =>
             // Executes the action applying all 
             // the policies defined in the wrapper
-            return await _policyWrapper
+            _policyWrapper.ExecuteAsync(() => action());
-                .ExecuteAsync(async () => await action());
-        }
     }
 
 }

src/Web/WebMVC/ViewComponents/Cart.cs

@@ -13,10 +13,7 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewComponents
     {
         private readonly IBasketService _cartSvc;
 
-        public Cart(IBasketService cartSvc)
+        public Cart(IBasketService cartSvc) => _cartSvc = cartSvc;
-        {
-            _cartSvc = cartSvc;
-        }
 
         public async Task<IViewComponentResult> InvokeAsync(ApplicationUser user)
         {

src/Web/WebMVC/ViewComponents/CartList.cs

@@ -12,19 +12,14 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewComponents
     {
         private readonly IBasketService _cartSvc;
 
-        public CartList(IBasketService cartSvc)
+        public CartList(IBasketService cartSvc) => _cartSvc = cartSvc;
-        {
-            _cartSvc = cartSvc;
-        }
 
         public async Task<IViewComponentResult> InvokeAsync(ApplicationUser user)
         {
             var item = await GetItemsAsync(user);
             return View(item);
         }
-        private async Task<Basket> GetItemsAsync(ApplicationUser user)
+        
-        {
+        private Task<Basket> GetItemsAsync(ApplicationUser user) => _cartSvc.GetBasket(user);
-            return await _cartSvc.GetBasket(user);
-        }
     }
 }

src/Web/WebMVC/ViewModels/Annotations/CardExpiration.cs

@@ -14,11 +14,20 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewModels.Annotations
             if (value == null)
                 return false;
 
-            var month = value.ToString().Split('/')[0];
+            var monthString = value.ToString().Split('/')[0];
-            var year = $"20{value.ToString().Split('/')[1]}";
+            var yearString = $"20{value.ToString().Split('/')[1]}";
-            DateTime d = new DateTime(int.Parse(year), int.Parse(month), 1);
+            // Use the 'out' variable initializer to simplify 
+            // the logic of validating the expiration date
+            if ((int.TryParse(monthString, out var month)) &&
+                (int.TryParse(yearString, out var year)))
+            {
+                DateTime d = new DateTime(year, month, 1);
 
-            return d > DateTime.UtcNow;
+                return d > DateTime.UtcNow;
+            } else
+            {
+                return false;
+            }
         }
     }
 }

src/Web/WebMVC/ViewModels/Basket.cs

@@ -7,11 +7,11 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewModels
 {
     public class Basket
     {
-        public Basket()
+        // Use property initializer syntax.
-        {
+        // While this is often more useful for read only 
-            Items = new List<BasketItem>();
+        // auto implemented properties, it can simplify logic
-        }
+        // for read/write properties.
-        public List<BasketItem> Items { get; set; }
+        public List<BasketItem> Items { get; set; } = new List<BasketItem>();
         public string BuyerId { get; set; }
 
         public decimal Total()

src/Web/WebMVC/ViewModels/CartViewModels/IndexViewModel.cs

@@ -9,6 +9,6 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewModels.CartViewModels
     public class CartComponentViewModel
     {
         public int ItemsCount { get; set; }
-        public string Disabled { get { return (ItemsCount == 0) ? "is-disabled" : ""; } }
+        public string Disabled => (ItemsCount == 0) ? "is-disabled" : "";
     }
 }

src/Web/WebMVC/ViewModels/Order.cs

@@ -11,10 +11,6 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewModels
 {
     public class Order
     {
-        public Order() {
-            OrderItems = new List<OrderItem>();
-        }
-
         public string OrderNumber {get;set;}
 
         public DateTime Date {get;set;}
@@ -53,7 +49,10 @@ namespace Microsoft.eShopOnContainers.WebMVC.ViewModels
 
         public string Buyer { get; set; }
 
-        public List<OrderItem> OrderItems { get; }
+        // See the property initializer syntax below. This
+        // initializes the compiler generated field for this
+        // auto-implemented property.
+        public List<OrderItem> OrderItems { get; } = new List<OrderItem>();
 
         [Required]
         public Guid RequestId { get; set; }