Merge pull request #6 from 2Toad/jp-4

Fixes #4: Add Reset method to Settings

README.md

@@ -85,6 +85,9 @@ The *Settings* object is a collection of mutable defaults used throughout the li
 // with Rijndael.Encrypt being just one of them. After making this change,
 // any future calls to Rijndael.Encrypt will make use of this new value
 Settings.HashIterations = 25000;
+
+// To reset all the settings to their default values
+Settings.Reset();
 ```
 
 ## Appendix

Rijndael256.Tests/SettingsTests.cs

@@ -10,13 +10,31 @@
 using System.Linq;
 using Xunit;
 
+// WARNING: HERE BE DRAGONS!
+// We must disable xUnit's asyncrhonous test excution because the Settings
+// object's default values are required by the other unit tests
+[assembly: CollectionBehavior(DisableTestParallelization = true)]
+
 namespace Rijndael256.Tests
 {
     public class SettingsTests
     {
         const string Plaintext = "A secret phrase to test hashing.";
         const string Salt = "0A9FDB669FA44FF1BEC484A1BE6B6E2A";
 
+        [Fact]
+        public void Reset()
+        {
+            var defaultHashIterations = Settings.HashIterations;
+
+            Settings.HashIterations = 777;
+            Assert.Equal(Settings.HashIterations, 777);
+            Assert.NotEqual(Settings.HashIterations, defaultHashIterations);
+
+            Settings.Reset();
+            Assert.Equal(Settings.HashIterations, defaultHashIterations);
+        }
+
         [Fact]
         public void HashIterations()
         {
@@ -30,16 +48,9 @@ public void HashIterations()
             var hashChanged = Hash.Pbkdf2(Plaintext, Salt, Settings.HashIterations);
             Assert.False(hashChanged.SequenceEqual(proofDefault));
 
-            RestoreDefaults();
-        }
-
-        /// <summary>
-        /// Settings is global, so we need to restore defaults before the other
-        /// unit tests, which depend on said defaults, are run.
-        /// </summary>
-        private void RestoreDefaults()
-        {
-            Settings.HashIterations = 10000;
+            // Settings is global, so we need to restore defaults before the other
+            // unit tests, which depend on said defaults, are run
+            Settings.Reset();
         }
     }
 }

Rijndael256/Settings.cs

@@ -13,10 +13,26 @@ namespace Rijndael256
     /// </summary>
     public static class Settings
     {
+        static Settings()
+        {
+            // Set defaults during initialization
+            Reset();
+        }
+
+        /// <summary>
+        /// Resets all the settings to their default values
+        /// </summary>
+        public static void Reset()
+        {
+            HashIterations = _hashIterations;
+        }
+
         /// <summary>
         /// The number of iterations used to derive hashes.
         /// Default is 10000.
         /// </summary>
-        public static int HashIterations = 10000;
+        public static int HashIterations;
+
+        private const int _hashIterations = 10000;
     }
 }