Merge branch 'enhancements/md5-folder' into enhancements/async-git-setup

Author: StanleyGoldman

GitHub.Unity.sln.DotSettings

@@ -335,6 +335,7 @@
   </TypePattern>
 &lt;/Patterns&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=ID/@EntryIndexedValue">ID</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=MD/@EntryIndexedValue">ME</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=SSH/@EntryIndexedValue">SSH</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateInstanceFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateStaticFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>

src/GitHub.Api/Extensions/FileSystemExtensions.cs

@@ -1,12 +1,29 @@
 using System;
+using System.IO;
+using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
 
 namespace GitHub.Unity
 {
     static class FileSystemExtensions
     {
-        public static string CalculateMD5(this IFileSystem fileSystem, string file)
+        public static string CalculateMD5(this IFileSystem fileSystem, string path)
+        {
+            if (fileSystem.DirectoryExists(path))
+            {
+                return fileSystem.CalculateFolderMD5(path);
+            }
+
+            if (fileSystem.FileExists(path))
+            {
+                return fileSystem.CalculateFileMD5(path);
+            }
+
+            throw new ArgumentException($@"Path does not exist: ""{path}""");
+        }
+
+        public static string CalculateFileMD5(this IFileSystem fileSystem, string file)
         {
             byte[] computeHash;
             using (var md5 = MD5.Create())
@@ -17,7 +34,36 @@ public static string CalculateMD5(this IFileSystem fileSystem, string file)
                 }
             }
 
-            return BitConverter.ToString(computeHash).Replace("-", string.Empty);
+            return BitConverter.ToString(computeHash).Replace("-", string.Empty).ToLower();
+        }
+
+        public static string CalculateFolderMD5(this IFileSystem fileSystem, string path)
+        {
+            //https://stackoverflow.com/questions/3625658/creating-hash-for-folder
+
+            var filePaths = fileSystem.GetFiles(path, "*", SearchOption.AllDirectories)
+                .OrderBy(p => p)
+                .ToArray();
+
+            using (var md5 = MD5.Create())
+            {
+                foreach (var filePath in filePaths)
+                {
+                    // hash path
+                    var relativeFilePath = filePath.Substring(path.Length + 1);
+                    var pathBytes = Encoding.UTF8.GetBytes(relativeFilePath);
+                    md5.TransformBlock(pathBytes, 0, pathBytes.Length, pathBytes, 0);
+
+                    // hash contents
+                    var contentBytes = File.ReadAllBytes(filePath);
+                    md5.TransformBlock(contentBytes, 0, contentBytes.Length, contentBytes, 0);
+                }
+
+                //Handles empty filePaths case
+                md5.TransformFinalBlock(new byte[0], 0, 0);
+
+                return BitConverter.ToString(md5.Hash).Replace("-", "").ToLower();
+            }
         }
     }
 }

src/GitHub.Api/IO/FileSystem.cs

@@ -167,6 +167,11 @@ public void WriteAllText(string path, string contents, Encoding encoding)
             File.WriteAllText(path, contents, encoding);
         }
 
+        public byte[] ReadAllBytes(string path)
+        {
+            return File.ReadAllBytes(path);
+        }
+
         public string ReadAllText(string path)
         {
             return File.ReadAllText(path);

src/GitHub.Api/IO/IFileSystem.cs

@@ -34,6 +34,7 @@ public interface IFileSystem
         void WriteAllText(string path, string contents);
         void WriteAllText(string path, string contents, Encoding encoding);
         void WriteAllLines(string path, string[] contents);
+        byte[] ReadAllBytes(string path);
         string ReadAllText(string path);
         string ReadAllText(string path, Encoding encoding);
         Stream OpenRead(string path);