Added license key class that had been lingering in the code snippets sections of my homepage for months now

git-svn-id: file:///srv/devel/repo-conversion/nusu@6 d2e56fa2-650e-0410-a79f-9358c0239efd

Source/Licensing/LicenseKey.Test.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections;
+
+#if UNITTEST
+
+using NUnit.Framework;
+
+namespace Nuclex.Licensing {
+
+  /// <summary>Unit test for the license key class</summary>
+  [TestFixture]
+  public class LicenseKeyTest {
+
+    /// <summary>Validates the correct translation of keys to GUIDs and back</summary>
+    [Test]
+    public void TestGuidKeyConversion() {
+
+      for(int i = 0; i < 128; ++i) {
+
+        // Create a new BitArray with the n.th bit set
+        BitArray guidBits = new BitArray(128);
+        guidBits[i] = true;
+
+        // Create a GUID from this Bitarray
+        byte[] guidBytes = new byte[16];
+        guidBits.CopyTo(guidBytes, 0);
+        Guid originalGuid = new Guid(guidBytes);
+
+        // Convert the GUID into a license key and back to a GUID
+        string licenseKey = new LicenseKey(originalGuid).ToString();
+        Guid rebuiltGuid = LicenseKey.Parse(licenseKey).ToGuid();
+
+        // Verify that the original GUID matches the fore-and-back converted one
+        Assert.AreEqual(originalGuid, rebuiltGuid, "Test for GUID bit " + i);
+
+      }
+
+    }
+
+    /// <summary>Tests whether license keys can be modified without destroying them</summary>
+    [Test]
+    public void TestKeyModification() {
+
+      for(int i = 0; i < 4; ++i) {
+        for(int j = 0; j < 8; ++j) {
+
+          LicenseKey testKey = new LicenseKey(
+            new Guid(-1, -1, -1, 255, 255, 255, 255, 255, 255, 255, 255)
+          );
+
+          string originalString = testKey.ToString();
+          testKey[i] &= ~(1 << j);
+          string modifiedString = testKey.ToString();
+
+          Assert.IsTrue(
+            originalString != modifiedString, "Modified string differs from original"
+          );
+
+          testKey[i] |= (1 << j);
+          string revertedString = testKey.ToString();
+
+          Assert.AreEqual(
+            originalString, revertedString, "Original state restorable"
+          );
+
+        } // for j
+      } // for i
+
+    }
+
+  }
+
+} // namespace Nuclex.Licensing
+
+#endif // UNITTEST