[cartservice] code cleanup (open-telemetry#943)

* File scope namespaces

* Sort modifiers

* Remove redundant type declaration

* Avoid hiding variables

* join declaration and assignment

* Use standard .NET convention for fields and consts

* inline out variable

* object initializer

* collection initializer

* drop unused using

* drop unused parameters

* remove redundant field initializer

---------

Co-authored-by: Austin Parker <austin@ap2.io>

src/cartservice/src/Program.cs

@@ -18,13 +18,12 @@
 
 var builder = WebApplication.CreateBuilder(args);
 string redisAddress = builder.Configuration["REDIS_ADDR"];
-RedisCartStore cartStore = null;
 if (string.IsNullOrEmpty(redisAddress))
 {
     Console.WriteLine("REDIS_ADDR environment variable is required.");
     Environment.Exit(1);
 }
-cartStore = new RedisCartStore(redisAddress);
+var cartStore = new RedisCartStore(redisAddress);
 
 // Initialize the redis store
 await cartStore.InitializeAsync();
@@ -41,15 +40,15 @@
 
 builder.Services.AddOpenTelemetry()
     .ConfigureResource(appResourceBuilder)
-    .WithTracing(builder => builder
+    .WithTracing(tracerBuilder => tracerBuilder
         .AddRedisInstrumentation(
             cartStore.GetConnection(),
             options => options.SetVerboseDatabaseStatements = true)
         .AddAspNetCoreInstrumentation()
         .AddGrpcClientInstrumentation()
         .AddHttpClientInstrumentation()
         .AddOtlpExporter())
-    .WithMetrics(builder => builder
+    .WithMetrics(meterBuilder => meterBuilder
         .AddRuntimeInstrumentation()
         .AddAspNetCoreInstrumentation()
         .AddOtlpExporter());

src/cartservice/src/cartstore/ICartStore.cs

@@ -2,17 +2,16 @@
 // SPDX-License-Identifier: Apache-2.0
 using System.Threading.Tasks;
 
-namespace cartservice.cartstore
+namespace cartservice.cartstore;
+
+public interface ICartStore
 {
-    public interface ICartStore
-    {
-        Task InitializeAsync();
+    Task InitializeAsync();
 
-        Task AddItemAsync(string userId, string productId, int quantity);
-        Task EmptyCartAsync(string userId);
+    Task AddItemAsync(string userId, string productId, int quantity);
+    Task EmptyCartAsync(string userId);
 
-        Task<Oteldemo.Cart> GetCartAsync(string userId);
+    Task<Oteldemo.Cart> GetCartAsync(string userId);
 
-        bool Ping();
-    }
+    bool Ping();
 }

src/cartservice/src/cartstore/LocalCartStore.cs

@@ -6,31 +6,31 @@
 using System.Linq;
 using System.Threading.Tasks;
 
-namespace cartservice.cartstore
+namespace cartservice.cartstore;
+
+internal class LocalCartStore : ICartStore
 {
-    internal class LocalCartStore : ICartStore
-    {
-        // Maps between user and their cart
-        private ConcurrentDictionary<string, Oteldemo.Cart> userCartItems = new ConcurrentDictionary<string, Oteldemo.Cart>();
-        private readonly Oteldemo.Cart emptyCart = new Oteldemo.Cart();
+    // Maps between user and their cart
+    private readonly ConcurrentDictionary<string, Oteldemo.Cart> _userCartItems = new();
+    private readonly Oteldemo.Cart _emptyCart = new();
 
-        public Task InitializeAsync()
-        {
-            Console.WriteLine("Local Cart Store was initialized");
+    public Task InitializeAsync()
+    {
+        Console.WriteLine("Local Cart Store was initialized");
 
-            return Task.CompletedTask;
-        }
+        return Task.CompletedTask;
+    }
 
-        public Task AddItemAsync(string userId, string productId, int quantity)
+    public Task AddItemAsync(string userId, string productId, int quantity)
+    {
+        Console.WriteLine($"AddItemAsync called with userId={userId}, productId={productId}, quantity={quantity}");
+        var newCart = new Oteldemo.Cart
         {
-            Console.WriteLine($"AddItemAsync called with userId={userId}, productId={productId}, quantity={quantity}");
-            var newCart = new Oteldemo.Cart
-                {
-                    UserId = userId,
-                    Items = { new Oteldemo.CartItem { ProductId = productId, Quantity = quantity } }
-                };
-            userCartItems.AddOrUpdate(userId, newCart,
-            (k, exVal) =>
+            UserId = userId,
+            Items = { new Oteldemo.CartItem { ProductId = productId, Quantity = quantity } }
+        };
+        _userCartItems.AddOrUpdate(userId, newCart,
+            (_, exVal) =>
             {
                 // If the item exists, we update its quantity
                 var existingItem = exVal.Items.SingleOrDefault(item => item.ProductId == productId);
@@ -46,35 +46,32 @@ public Task AddItemAsync(string userId, string productId, int quantity)
                 return exVal;
             });
 
-            return Task.CompletedTask;
-        }
+        return Task.CompletedTask;
+    }
 
-        public Task EmptyCartAsync(string userId)
-        {
-            var eventTags = new ActivityTagsCollection();
-            eventTags.Add("userId", userId);
-            Activity.Current?.AddEvent(new ActivityEvent("EmptyCartAsync called.", default, eventTags));
+    public Task EmptyCartAsync(string userId)
+    {
+        var eventTags = new ActivityTagsCollection {{"userId", userId}};
+        Activity.Current?.AddEvent(new ActivityEvent("EmptyCartAsync called.", default, eventTags));
 
-            userCartItems[userId] = new Oteldemo.Cart();
-            return Task.CompletedTask;
-        }
+        _userCartItems[userId] = new Oteldemo.Cart();
+        return Task.CompletedTask;
+    }
 
-        public Task<Oteldemo.Cart> GetCartAsync(string userId)
+    public Task<Oteldemo.Cart> GetCartAsync(string userId)
+    {
+        Console.WriteLine($"GetCartAsync called with userId={userId}");
+        if (!_userCartItems.TryGetValue(userId, out var cart))
         {
-            Console.WriteLine($"GetCartAsync called with userId={userId}");
-            Oteldemo.Cart cart = null;
-            if (!userCartItems.TryGetValue(userId, out cart))
-            {
-                Console.WriteLine($"No carts for user {userId}");
-                return Task.FromResult(emptyCart);
-            }
-
-            return Task.FromResult(cart);
+            Console.WriteLine($"No carts for user {userId}");
+            return Task.FromResult(_emptyCart);
         }
 
-        public bool Ping()
-        {
-            return true;
-        }
+        return Task.FromResult(cart);
+    }
+
+    public bool Ping()
+    {
+        return true;
     }
 }