(#7) Move StreamExtensions to child namespace

X10D/src/StreamExtensions.cs

@@ -1,32 +0,0 @@
-using System;
-using System.IO;
-using System.Security.Cryptography;
-
-namespace X10D
-{
-    /// <summary>
-    ///     Extension methods for <see cref="Stream" />.
-    /// </summary>
-    public static class StreamExtensions
-    {
-        /// <summary>
-        ///     Returns the hash of a stream using the specified hashing algorithm.
-        /// </summary>
-        /// <typeparam name="T">A <see cref="HashAlgorithm" /> derived type.</typeparam>
-        /// <param name="stream">The stream whose hash is to be computed.</param>
-        /// <returns>Returns a <see cref="byte" /> array representing the hash of the stream.</returns>
-        /// <exception cref="ArgumentNullException"><paramref name="stream" /> is <see langword="null" />.</exception>
-        public static byte[] GetHash<T>(this Stream stream)
-            where T : HashAlgorithm
-        {
-            if (stream is null)
-            {
-                throw new ArgumentNullException(nameof(stream));
-            }
-
-            var create = typeof(T).GetMethod("Create", Array.Empty<Type>());
-            using var crypt = (T)create?.Invoke(null, null);
-            return crypt?.ComputeHash(stream);
-        }
-    }
-}

X10D/src/StreamExtensions/StreamExtensions.cs

@@ -0,0 +1,53 @@
+using System;
+using System.IO;
+using System.Security.Cryptography;
+
+namespace X10D.StreamExtensions
+{
+    /// <summary>
+    ///     Extension methods for <see cref="Stream" />.
+    /// </summary>
+    public static class StreamExtensions
+    {
+        /// <summary>
+        ///     Returns the hash of a stream using the specified hash algorithm.
+        /// </summary>
+        /// <typeparam name="T">A <see cref="HashAlgorithm" /> derived type.</typeparam>
+        /// <param name="stream">The stream whose hash is to be computed.</param>
+        /// <returns>A <see cref="byte" /> array representing the hash of the stream.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="stream" /> is <see langword="null" />.</exception>
+        /// <exception cref="ArgumentException">
+        ///     <typeparamref name="T" /> does not offer a static <c>Create</c> method.
+        ///     -or-
+        ///     An invocation to the static <c>Create</c> method defined in <typeparamref name="T" /> returned
+        ///     <see langword="null" />.
+        /// </exception>
+        /// <exception cref="ObjectDisposedException">The stream has already been disposed.</exception>
+        /// <remarks>This method consumes the stream from its current position!.</remarks>
+        public static byte[] GetHash<T>(this Stream stream)
+            where T : HashAlgorithm
+        {
+            if (stream is null)
+            {
+                throw new ArgumentNullException(nameof(stream));
+            }
+
+            var type = typeof(T);
+            var create = type.GetMethod("Create", Array.Empty<Type>());
+            if (create is null)
+            {
+                throw new TypeInitializationException(type.FullName,
+                    new ArgumentException(ExceptionMessages.HashAlgorithmNoCreateMethod));
+            }
+
+            using var crypt = create.Invoke(null, null) as T;
+            if (crypt is null)
+            {
+                throw new TypeInitializationException(type.FullName,
+                    new ArgumentException(ExceptionMessages.HashAlgorithmCreateReturnedNull));
+            }
+
+            return crypt.ComputeHash(stream);
+        }
+    }
+}