Cleanup for CSHARP-379

Author: sridharn

Bson/BsonUtils.cs

@@ -24,20 +24,23 @@
 
 namespace MongoDB.Bson
 {
+
     /// <summary>
     /// A static class containing BSON utility methods.
     /// </summary>
     public static class BsonUtils
     {
 
+        // public static methods
+
         /// <summary>
         /// Parses a hex string into its equivalent byte array.
         /// </summary>
         /// <param name="s">The hex string to parse.</param>
         /// <returns>The byte equivalent of the hex string.</returns>
         public static byte[] ParseHexString(string s)
         {
-            if (string.IsNullOrEmpty(s))
+            if (s == null)
             {
                 throw new ArgumentNullException("s");
             }
@@ -59,7 +62,8 @@ public static byte[] ParseHexString(string s)
                 catch (FormatException e)
                 {
                     throw new FormatException(
-                        string.Format("Invalid hex string. Problem with substring {0} starting at position {1}",
+                        string.Format("Invalid hex string {0}. Problem with substring {1} starting at position {2}",
+                        s,
                         hex,
                         2 * i),
                         e);

BsonUnitTests/BsonUtilsTests.cs

@@ -127,10 +127,11 @@ public void TestParseHexStringNull()
         }
 
         [Test]
-        [ExpectedException(typeof(ArgumentNullException))]
         public void TestParseHexStringEmpty()
         {
+            byte[] expected = new byte[0];
             var actual = BsonUtils.ParseHexString(string.Empty);
+            Assert.AreEqual(expected, actual);
         }
 
         [Test]
@@ -168,17 +169,20 @@ public void TestParseHexStringInvalid2()
         [Test]
         public void TestTryParseHexStringNull()
         {
-            byte[] expected;
-            BsonUtils.TryParseHexString(null, out expected);
-            Assert.IsNull(expected);
+            byte[] actual;
+            var result = BsonUtils.TryParseHexString(null, out actual);
+            Assert.IsFalse(result);
+            Assert.IsNull(actual);
         }
 
         [Test]
         public void TestTryParseHexStringEmpty()
         {
-            byte[] expected;
-            var actual = BsonUtils.TryParseHexString(string.Empty, out expected);
-            Assert.IsNull(expected);
+            byte[] expected = new byte[0];
+            byte[] actual;
+            var result = BsonUtils.TryParseHexString(string.Empty, out actual);
+            Assert.IsTrue(result);
+            Assert.AreEqual(expected, actual);
         }
 
         [Test]
@@ -187,7 +191,8 @@ public void TestTryParseHexString()
             var expected = new byte[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 255 };
             var value = "000102030405060708090a0b0c0d0e0f10ff";
             byte[] actual;
-            BsonUtils.TryParseHexString(value, out actual);
+            var result = BsonUtils.TryParseHexString(value, out actual);
+            Assert.IsTrue(result);
             Assert.AreEqual(expected, actual);
         }
 
@@ -197,24 +202,27 @@ public void TestTryParseHexStringOdd()
             var expected = new byte[] { 0, 15 };
             var value = "00f";
             byte[] actual;
-            BsonUtils.TryParseHexString(value, out actual);
+            var result = BsonUtils.TryParseHexString(value, out actual);
+            Assert.IsTrue(result);
             Assert.AreEqual(expected, actual);
         }
 
         [Test]
         public void TestTryParseHexStringInvalid()
         {
-            byte[] expected;
-            var actual = BsonUtils.TryParseHexString("1G", out expected);
-            Assert.IsNull(expected);
+            byte[] actual;
+            var result = BsonUtils.TryParseHexString("1G", out actual);
+            Assert.IsFalse(result);
+            Assert.IsNull(actual);
         }
 
         [Test]
         public void TestTryParseHexStringInvalid2()
         {
-            byte[] expected;
-            var actual = BsonUtils.TryParseHexString("00 1", out expected);
-            Assert.IsNull(expected);
+            byte[] actual;
+            var result = BsonUtils.TryParseHexString("00 1", out actual);
+            Assert.IsFalse(result);
+            Assert.IsNull(actual);
         }
 
     }