Feature - use default CacheConfiguration instead of allowCaching (#255)

* Feature - use default CacheConfiguration instead of �llowCaching

* pr-trail: add some extra guards against invalid passed-along arguments

* Update CacheConfiguration.cs

* pr-sug: make the default ctor obsolete

Author: stijnmoreels

docs/preview/features/secret-store/provider/key-vault.md

@@ -17,6 +17,7 @@ PM > Install-Package Arcus.Security.Providers.AzureKeyVault
 After installing the package, the addtional extensions becomes available when building the secret store.
 
 ```csharp
+using Arcus.Security.Core.Caching.Configuration;
 using Microsoft.Extensions.Hosting;
 
 public class Program
@@ -48,7 +49,7 @@ public class Program
                         builder.AddAzureKeyVault(vaultAuthentication, vaultConfiguration);
 
                         // Adding a default cached variant of the Azure Key Vault provider (default: 5 min caching).
-                        builder.AddAzureKeyVaultWithManagedIdentity(keyVaultUri, allowCaching: true);
+                        builder.AddAzureKeyVaultWithManagedIdentity(keyVaultUri, cacheConfiguration: CacheConfiguration.Default);
 
                         // Assing a configurable cached variant of the Azure Key Vault provider.
                         var cacheConfiguration = new CacheConfiguration(TimeSpan.FromMinutes(1));

src/Arcus.Security.Core/Caching/CachedSecretProvider.cs

@@ -62,7 +62,7 @@ public CachedSecretProvider(ISecretProvider secretProvider, ICacheConfiguration
         /// </summary>
         /// <exception cref="ArgumentNullException">Thrown when the <paramref name="secretProvider"/> is <c>null</c>.</exception>
         public CachedSecretProvider(ISecretProvider secretProvider) :
-            this(secretProvider, new CacheConfiguration(), new MemoryCache(new MemoryCacheOptions()))
+            this(secretProvider, CacheConfiguration.Default, new MemoryCache(new MemoryCacheOptions()))
         {
         }
 

src/Arcus.Security.Core/Caching/Configuration/CacheConfiguration.cs

@@ -9,28 +9,32 @@ namespace Arcus.Security.Core.Caching.Configuration
     public class CacheConfiguration : ICacheConfiguration
     {
         /// <summary>
-        ///     Duration for which an entry should be cached
+        /// Initializes a new instance of the <see cref="CacheConfiguration"/> class with default cache entry of 5 minutes.
         /// </summary>
-        public TimeSpan Duration { get; }
+        [Obsolete ("Use the " + nameof(Default) + " static property to retrieve a default caching configuration instance")]
+        public CacheConfiguration() : this(TimeSpan.FromMinutes(5))
+        {
+        }
 
         /// <summary>
-        ///     Constructor
+        /// Initializes a new instance of the <see cref="CacheConfiguration"/> class.
         /// </summary>
         /// <param name="duration">Duration for which an entry should be cached</param>
         /// <exception cref="ArgumentOutOfRangeException">Thrown when the cache duration is not a positive time duration.</exception>
         public CacheConfiguration(TimeSpan duration)
         {
             Guard.NotLessThan(duration, TimeSpan.Zero, nameof(duration), "Requires a positive time duration in which the caching should take place");
-
             Duration = duration;
         }
 
         /// <summary>
-        ///     Constructor with default cache entry of 5 minutes
+        /// Gets the default <see cref="ICacheConfiguration"/> that takes in 5 minutes as default cache duration.
         /// </summary>
-        public CacheConfiguration()
-        {
-            Duration = TimeSpan.FromMinutes(5);
-        }
+        public static ICacheConfiguration Default { get; } = new CacheConfiguration(TimeSpan.FromMinutes(5));
+
+        /// <summary>
+        /// Gets the duration for which an entry should be cached.
+        /// </summary>
+        public TimeSpan Duration { get; }
     }
-}
+}

src/Arcus.Security.Core/Caching/Configuration/ICacheConfiguration.cs

@@ -8,7 +8,7 @@ namespace Arcus.Security.Core.Caching.Configuration
     public interface ICacheConfiguration
     {
         /// <summary>
-        ///     Duration for which an entry should be cached
+        /// Gets the duration for which an entry should be cached.
         /// </summary>
         TimeSpan Duration { get; }
     }

src/Arcus.Security.Core/Caching/SecretProviderCachingExtensions.cs

@@ -24,7 +24,7 @@ public static ICachedSecretProvider WithCaching(this ISecretProvider secretProvi
             Guard.NotNull(secretProvider, nameof(secretProvider), "Requires a secret provider instance to include caching while retrieving secrets");
             Guard.NotLessThan(cachingDuration, TimeSpan.Zero, nameof(cachingDuration), "Requires a positive time duration in which the caching should take place");
             Guard.NotNull(memoryCache, nameof(memoryCache), "Requires a memory caching implementation to include caching while retrieving secrets");
-            
+
             return new CachedSecretProvider(secretProvider, new CacheConfiguration(cachingDuration), memoryCache);
         }
 
@@ -41,7 +41,7 @@ public static ICachedSecretProvider WithCaching(this ISecretProvider secretProvi
         {
             Guard.NotNull(secretProvider, nameof(secretProvider), "Requires a secret provider instance to include caching while retrieving secrets");
             Guard.NotLessThan(cachingDuration, TimeSpan.Zero, nameof(cachingDuration), "Requires a positive time duration in which the caching should take place");
-            
+
             return new CachedSecretProvider(secretProvider, new CacheConfiguration(cachingDuration));
         }
 
@@ -55,7 +55,7 @@ public static ICachedSecretProvider WithCaching(this ISecretProvider secretProvi
         public static ICachedSecretProvider WithCaching(this ISecretProvider secretProvider)
         {
             Guard.NotNull(secretProvider, nameof(secretProvider), "Requires a secret provider instance to include caching while retrieving secrets");
-            
+
             return new CachedSecretProvider(secretProvider);
         }
     }