Managed implementation of git repo data reading

Author: tmat

src/Directory.Build.props

@@ -3,7 +3,7 @@
   <Import Project="Sdk.props" Sdk="Microsoft.DotNet.Arcade.Sdk" />
 
   <PropertyGroup>
-    <LangVersion>Latest</LangVersion>
+    <LangVersion>Preview</LangVersion>
     <Copyright>$(CopyrightMicrosoft)</Copyright>
     <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
     <GenerateResxSource>true</GenerateResxSource>

src/Microsoft.Build.Tasks.Git.Operations/GitOperations.cs

@@ -26,8 +26,13 @@ public static string LocateRepository(string directory)
             return Repository.Discover(directory);
         }
 
+        internal static IRepository CreateRepository(string root)
+            => new Repository(root);
+
         public static string GetRepositoryUrl(IRepository repository, Action<string, object[]> logWarning = null, string remoteName = null)
         {
+            // GetVariableValue("remote", name, "url");
+
             var remotes = repository.Network.Remotes;
             var remote = string.IsNullOrEmpty(remoteName) ? (remotes["origin"] ?? remotes.FirstOrDefault()) : remotes[remoteName];
             if (remote == null)
@@ -179,15 +184,6 @@ public static ITaskItem[] GetSourceRoots(IRepository repository, Action<string,
                     }
 
                     // https://git-scm.com/docs/git-submodule
-                    // <repository> is the URL of the new submodule's origin repository. This may be either an absolute URL, or (if it begins with ./ or ../), 
-                    // the location relative to the superproject's default remote repository (Please note that to specify a repository foo.git which is located 
-                    // right next to a superproject bar.git, you'll have to use ../foo.git instead of ./foo.git - as one might expect when following the rules 
-                    // for relative URLs -- because the evaluation of relative URLs in Git is identical to that of relative directories).
-                    //
-                    // The given URL is recorded into .gitmodules for use by subsequent users cloning the superproject. 
-                    // If the URL is given relative to the superproject's repository, the presumption is the superproject and submodule repositories
-                    // will be kept together in the same relative location, and only the superproject's URL needs to be provided.git --
-                    // submodule will correctly locate the submodule using the relative URL in .gitmodules.
                     var submoduleUrl = NormalizeUrl(submodule.Url, repoRoot);
                     if (submoduleUrl == null)
                     {

src/Microsoft.Build.Tasks.Git.Operations/Managed/CharUtils.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.Build.Tasks.Git
+{
+    internal static class CharUtils
+    {
+        public static char[] AsciiWhitespace = { ' ', '\t', '\n', '\f', '\r', '\v' };
+
+        public static bool IsHexadecimalDigit(char c)
+            => c >= '0' && c <= '9' || c >= 'A' && c <= 'F' || c >= 'a' && c <= 'f';
+    }
+}