Adding "FrameworkAlternate" and "Index" to XSD

Updated to add attributes to MemberSignature, TypeSignature, Parameter, TypeParameter.
Additionally, added validation unit tests, and reformatted the mdoc validator subcommand for future-proof maintainability.
Closes #262

11 files changed, 383 insertions, 184 deletions

diff --git a/mdoc/Consts.cs b/mdoc/Consts.cs
index d435c1d0..e049b679 100644
--- a/mdoc/Consts.cs
+++ b/mdoc/Consts.cs
@@ -26,5 +26,7 @@ namespace Mono.Documentation
 		public const string RefTypeObsoleteString = "Types with embedded references are not supported in this version of your compiler.";
 		public const string CompilerGeneratedAttribute = "System.Runtime.CompilerServices.CompilerGeneratedAttribute";
 		public const string CompilationMappingAttribute = "Microsoft.FSharp.Core.CompilationMappingAttribute";
+        public const string FrameworksIndex = "FrameworksIndex";
+		public const string FrameworkAlternate = "FrameworkAlternate";
     }
 }
diff --git a/mdoc/Mono.Documentation/MDocUpdater.cs b/mdoc/Mono.Documentation/MDocUpdater.cs
index 46b0d895..1345b859 100644
--- a/mdoc/Mono.Documentation/MDocUpdater.cs
+++ b/mdoc/Mono.Documentation/MDocUpdater.cs
@@ -285,7 +285,7 @@ namespace Mono.Documentation
                                                {
                                                    Name = f.Attribute("Name").Value,
                                                    Source = f.Attribute("Source").Value,
-                                                   XmlPath = Path.Combine(srcPath, "FrameworksIndex", f.Attribute("Source").Value + ".xml"),
+                                                   XmlPath = Path.Combine(srcPath, Consts.FrameworksIndex, f.Attribute("Source").Value + ".xml"),
                                                })
                                                .Where(f => File.Exists(f.XmlPath))
                                                .Select(f => XDocument.Load(f.XmlPath));
@@ -1238,7 +1238,7 @@ namespace Mono.Documentation
         private void CleanupFiles (string dest, HashSet<string> goodfiles)
         {
             // Look for files that no longer correspond to types
-            foreach (System.IO.DirectoryInfo nsdir in new System.IO.DirectoryInfo (dest).GetDirectories ("*").Where (d => Path.GetFileName (d.FullName) != "FrameworksIndex"))
+            foreach (System.IO.DirectoryInfo nsdir in new System.IO.DirectoryInfo (dest).GetDirectories ("*").Where (d => Path.GetFileName (d.FullName) != Consts.FrameworksIndex))
             {
                 foreach (System.IO.FileInfo typefile in nsdir.GetFiles ("*.xml"))
                 {
@@ -1997,7 +1997,7 @@ namespace Mono.Documentation
                             if (!existing.Any ())
                             {
                                 var newNode = WriteElementText (basenode, "BaseTypeName", basetypename, forceNewElement: true);
-                                WriteElementAttribute (basenode, newNode, "FrameworkAlternate", typeEntry.Framework.Name);
+                                WriteElementAttribute (basenode, newNode, Consts.FrameworkAlternate, typeEntry.Framework.Name);
                             }
                         }
                     }
@@ -2240,33 +2240,33 @@ namespace Mono.Documentation
             if (existingNodes.Count () > 1) {
                 //  find the right one to update based on `currentFX`
 
-                if (existingNodes.Any (e => e.HasAttribute ("FrameworkAlternate"))) {
-                    var nodesWithFX = existingNodes.Where (e => e.HasAttribute ("FrameworkAlternate"));
+                if (existingNodes.Any (e => e.HasAttribute (Consts.FrameworkAlternate))) {
+                    var nodesWithFX = existingNodes.Where (e => e.HasAttribute (Consts.FrameworkAlternate));
                     if (nodesWithFX.Any ()) {
                         // one exists, we can continue
                         if (!fxAlternateTriggered)
                         {
-                            var matchingSignature = nodesWithFX.FirstOrDefault (nfx => nfx.GetAttribute ("Value") == valueToUse && !nfx.GetAttribute ("FrameworkAlternate").Contains (currentFX));
+                            var matchingSignature = nodesWithFX.FirstOrDefault (nfx => nfx.GetAttribute ("Value") == valueToUse && !nfx.GetAttribute (Consts.FrameworkAlternate).Contains (currentFX));
                             if (matchingSignature!= null) {
                                 // The current implementation has changed
-                                matchingSignature.SetAttribute ("FrameworkAlternate", FXUtils.AddFXToList (matchingSignature.GetAttribute ("FrameworkAlternate"), currentFX));
+                                matchingSignature.SetAttribute (Consts.FrameworkAlternate, FXUtils.AddFXToList (matchingSignature.GetAttribute (Consts.FrameworkAlternate), currentFX));
                                 foreach (var n in nodesWithFX.Where (nfx => nfx != matchingSignature))
                                 {
-                                    string nfx = n.GetAttribute ("FrameworkAlternate");
+                                    string nfx = n.GetAttribute (Consts.FrameworkAlternate);
                                     string nfixed = FXUtils.RemoveFXFromList (nfx, currentFX);
                                     if (string.IsNullOrEmpty (nfixed))
                                     {
                                         n.ParentNode.RemoveChild (n);
                                         var nodesWithoutFX = existingNodes
-                                            .Where (e => e.HasAttribute ("FrameworkAlternate") && !e.GetAttribute ("FrameworkAlternate").Contains (currentFX))
-                                            .Select (e => new { Element = e, FX = e.GetAttribute ("FrameworkAlternate") });
+                                            .Where (e => e.HasAttribute (Consts.FrameworkAlternate) && !e.GetAttribute (Consts.FrameworkAlternate).Contains (currentFX))
+                                            .Select (e => new { Element = e, FX = e.GetAttribute (Consts.FrameworkAlternate) });
                                         foreach (var nwofx in nodesWithoutFX)
                                         {
-                                            nwofx.Element.SetAttribute ("FrameworkAlternate", FXUtils.AddFXToList (nwofx.FX, currentFX));
+                                            nwofx.Element.SetAttribute (Consts.FrameworkAlternate, FXUtils.AddFXToList (nwofx.FX, currentFX));
                                         }
                                     }
                                     else
-                                        n.SetAttribute ("FrameworkAlternate", nfixed);
+                                        n.SetAttribute (Consts.FrameworkAlternate, nfixed);
                                 }
                             }
 
@@ -2290,7 +2290,7 @@ namespace Mono.Documentation
                 if (!string.IsNullOrWhiteSpace (previousFX))
                 {
                     var node = existingNodes.First ();
-                    node.SetAttribute ("FrameworkAlternate", previousFX);
+                    node.SetAttribute (Consts.FrameworkAlternate, previousFX);
                 }
                 else 
                 {
@@ -2300,13 +2300,13 @@ namespace Mono.Documentation
                 }
 
                 var newelement = makeNewNode ();
-                newelement.SetAttribute ("FrameworkAlternate", currentFX);
+                newelement.SetAttribute (Consts.FrameworkAlternate, currentFX);
                 return;
             }
-            else if (!fxAlternateTriggered && existingNodes.Count () == 1 && typeEntry.Framework.Frameworks.Count () > 1 && existingNodes.First ().HasAttribute ("FrameworkAlternate")) {
+            else if (!fxAlternateTriggered && existingNodes.Count () == 1 && typeEntry.Framework.Frameworks.Count () > 1 && existingNodes.First ().HasAttribute (Consts.FrameworkAlternate)) {
                 var node = existingNodes.First ();
-                string newfxvalue = FXUtils.AddFXToList (node.GetAttribute ("FrameworkAlternate"), typeEntry.Framework.Name);
-                node.SetAttribute ("FrameworkAlternate", newfxvalue);
+                string newfxvalue = FXUtils.AddFXToList (node.GetAttribute (Consts.FrameworkAlternate), typeEntry.Framework.Name);
+                node.SetAttribute (Consts.FrameworkAlternate, newfxvalue);
                 return;
             }
 
@@ -3293,10 +3293,10 @@ namespace Mono.Documentation
                 if (alreadyExists != null)
                 {
                     // if FXA, add fx.name
-                    if (fx.Frameworks.Count() > 1 && alreadyExists.XElement.HasAttribute("FrameworkAlternate"))
+                    if (fx.Frameworks.Count() > 1 && alreadyExists.XElement.HasAttribute(Consts.FrameworkAlternate))
                     {
-                        var newfxlist = FXUtils.AddFXToList (alreadyExists.XElement.GetAttribute ("FrameworkAlternate"), fx.Name);
-                        alreadyExists.XElement.SetAttribute ("FrameworkAlternate", newfxlist);
+                        var newfxlist = FXUtils.AddFXToList (alreadyExists.XElement.GetAttribute (Consts.FrameworkAlternate), fx.Name);
+                        alreadyExists.XElement.SetAttribute (Consts.FrameworkAlternate, newfxlist);
                     }
                     continue;
                 }
@@ -3313,7 +3313,7 @@ namespace Mono.Documentation
 
                     if (fx.Frameworks.Count() > 1 && !fx.IsFirstFramework && (!typeNotExisted && !assemblyNotExisted))
                     {
-                        ae.SetAttribute ("FrameworkAlternate", fx.Name);
+                        ae.SetAttribute (Consts.FrameworkAlternate, fx.Name);
                     }
                 }
             }
@@ -3331,17 +3331,17 @@ namespace Mono.Documentation
                     
                     if (fx.Frameworks.Count() > 1) {
                         
-                        if (stateAttribute.XElement.HasAttribute ("FrameworkAlternate"))
+                        if (stateAttribute.XElement.HasAttribute (Consts.FrameworkAlternate))
                         {
                             // if has FXA, remove from list
-                            var newfxlist = FXUtils.RemoveFXFromList (stateAttribute.XElement.GetAttribute ("FrameworkAlternate"), fx.Name);
-                            stateAttribute.XElement.SetAttribute ("FrameworkAlternate", newfxlist);
+                            var newfxlist = FXUtils.RemoveFXFromList (stateAttribute.XElement.GetAttribute (Consts.FrameworkAlternate), fx.Name);
+                            stateAttribute.XElement.SetAttribute (Consts.FrameworkAlternate, newfxlist);
                         }
                         else if (!fx.IsFirstFramework) // doesn't have FXA, and isn't the first framework
                         {
                             // if not, we need to make sure
                             var priorfxList = fx.PreviousFrameworks.Select (f => f.Name).ToArray ();
-                            stateAttribute.XElement.SetAttribute ("FrameworkAlternate", string.Join (";", priorfxList));
+                            stateAttribute.XElement.SetAttribute (Consts.FrameworkAlternate, string.Join (";", priorfxList));
                         }
                         else if (fx.IsFirstFramework)
                         {
@@ -3356,7 +3356,7 @@ namespace Mono.Documentation
             // clean up
             if (fx.IsLastFramework) {
                 foreach(var attr in e.ChildNodes.Cast<XmlElement> ().ToArray()) {
-                    if (attr.HasAttribute ("FrameworkAlternate") && string.IsNullOrWhiteSpace (attr.GetAttribute ("FrameworkAlternate")))
+                    if (attr.HasAttribute (Consts.FrameworkAlternate) && string.IsNullOrWhiteSpace (attr.GetAttribute (Consts.FrameworkAlternate)))
                         attr.ParentNode.RemoveChild (attr);
                 }
             }
@@ -3448,7 +3448,7 @@ namespace Mono.Documentation
                 if (addIndex)
                     pe.SetAttribute ("Index", index.ToString ());
                 if (addfx)
-                    pe.SetAttribute ("FrameworkAlternate", fx);
+                    pe.SetAttribute (Consts.FrameworkAlternate, fx);
 
 				MakeAttributes (pe, GetCustomAttributes (param.CustomAttributes, ""), typeEntry.Framework, typeEntry: typeEntry);
             };
@@ -3496,7 +3496,7 @@ namespace Mono.Documentation
                                  Type = n.GetAttribute ("Type"),
                                  ChildIndex = i,
                                  ActualIndex = actualIndex,
-                                 FrameworkAlternates = n.GetAttribute ("FrameworkAlternate")
+                                 FrameworkAlternates = n.GetAttribute (Consts.FrameworkAlternate)
                              };
                          })
                          .ToArray ();
@@ -3510,8 +3510,8 @@ namespace Mono.Documentation
                 if (xitem != null)
                 {
                     var xelement = xitem.Element;
-                    if (xelement.HasAttribute ("FrameworkAlternate") && !xelement.GetAttribute ("FrameworkAlternate").Contains (typeEntry.Framework.Name))
-                        xelement.SetAttribute ("FrameworkAlternate", FXUtils.AddFXToList (xelement.GetAttribute ("FrameworkAlternate"), typeEntry.Framework.Name));
+                    if (xelement.HasAttribute (Consts.FrameworkAlternate) && !xelement.GetAttribute (Consts.FrameworkAlternate).Contains (typeEntry.Framework.Name))
+                        xelement.SetAttribute (Consts.FrameworkAlternate, FXUtils.AddFXToList (xelement.GetAttribute (Consts.FrameworkAlternate), typeEntry.Framework.Name));
                         
                     
                     continue;
@@ -3528,7 +3528,7 @@ namespace Mono.Documentation
 
                         //-find < parameter where index = currentIndex >
                         var currentNode = xdata[i].Element;
-                        currentNode.SetAttribute ("FrameworkAlternate", fxList);
+                        currentNode.SetAttribute (Consts.FrameworkAlternate, fxList);
 
                         addParameter (p.Definition, currentNode, p.Type, i, true, typeEntry.Framework.Name, true);
 
@@ -3556,8 +3556,8 @@ namespace Mono.Documentation
                 {
                     Element = p,
                     Name = p.GetAttribute ("Name"),
-                    HasFrameworkAlternate = p.HasAttribute ("FrameworkAlternate"),
-                    FrameworkAlternate = p.GetAttribute ("FrameworkAlternate")
+                    HasFrameworkAlternate = p.HasAttribute (Consts.FrameworkAlternate),
+                    FrameworkAlternate = p.GetAttribute (Consts.FrameworkAlternate)
                 })
                 .Where (p =>
                         p.HasFrameworkAlternate && 
@@ -3577,7 +3577,7 @@ namespace Mono.Documentation
                     }
                     else
                     {
-                        a.Element.SetAttribute ("FrameworkAlternate", newValue);
+                        a.Element.SetAttribute (Consts.FrameworkAlternate, newValue);
                     }
                 }
             }
diff --git a/mdoc/Mono.Documentation/MDocValidator.cs b/mdoc/Mono.Documentation/MDocValidator.cs
new file mode 100644
index 00000000..1716313b
--- /dev/null
+++ b/mdoc/Mono.Documentation/MDocValidator.cs
@@ -0,0 +1,156 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Reflection;
+using System.Xml;
+using System.Xml.Schema;
+
+using Mono.Options;
+
+namespace Mono.Documentation
+{
+    public class MDocValidator : MDocCommand
+    {
+        XmlReaderSettings settings;
+        long errors = 0;
+
+        public override void Run (IEnumerable<string> args)
+        {
+            string[] validFormats = {
+                "ecma",
+            };
+            string format = "ecma";
+            var p = new OptionSet () {
+                { "f|format=",
+                    "The documentation {0:FORMAT} used within PATHS.  " +
+                        "Valid formats include:\n  " +
+                        string.Join ("\n  ", validFormats) + "\n" +
+                        "If no format provided, `ecma' is used.",
+                    v => format = v },
+            };
+            List<string> files = Parse (p, args, "validate",
+                    "[OPTIONS]+ PATHS",
+                    "Validate PATHS against the specified format schema.");
+            if (files == null)
+                return;
+            if (Array.IndexOf (validFormats, format) < 0)
+                Error ("Invalid documentation format: {0}.", format);
+            Run (format, files);
+        }
+
+        public void Run (string format, IEnumerable<string> files)
+        {
+            InitializeSchema (format);
+
+            // skip args[0] because it is the provider name
+            foreach (string arg in files)
+            {
+                if (IsMonodocFile (arg))
+                    ValidateFile (arg);
+
+                if (Directory.Exists (arg))
+                {
+                    RecurseDirectory (arg);
+                }
+            }
+
+            Message (errors == 0 ? TraceLevel.Info : TraceLevel.Error,
+                    "Total validation errors: {0}", errors);
+        }
+
+        public void InitializeSchema (string format, ValidationEventHandler extraHandler = null)
+        {
+            Stream s = null;
+
+            switch (format)
+            {
+                case "ecma":
+                    s = Assembly.GetExecutingAssembly ().GetManifestResourceStream ("monodoc-ecma.xsd");
+                    break;
+
+                default:
+                    throw new NotSupportedException (string.Format ("The format `{0}' is not suppoted.", format));
+            }
+
+            if (s == null)
+                throw new NotSupportedException (string.Format ("The schema for `{0}' was not found.", format));
+
+            settings = new XmlReaderSettings ();
+            settings.Schemas.Add (XmlSchema.Read (s, null));
+            settings.Schemas.Compile ();
+            settings.ValidationType = ValidationType.Schema;
+            settings.ValidationEventHandler += OnValidationEvent;
+            if (extraHandler != null) 
+                settings.ValidationEventHandler += extraHandler;
+        }
+
+        public void ValidateFile (string file)
+        {
+            if (settings == null) InitializeSchema ("ecma");
+
+            try
+            {
+                using (var reader = XmlReader.Create (new XmlTextReader (file), settings))
+                {
+                    while (reader.Read ())
+                    {
+                        // do nothing
+                    }
+                }
+            }
+            catch (Exception e)
+            {
+                Message (TraceLevel.Error, "mdoc: {0}", e.ToString ());
+            }
+        }
+
+        public void ValidateFile (TextReader textReader)
+        {
+            if (settings == null) InitializeSchema ("ecma");
+
+            try 
+            {
+                using (var xmlReader = XmlReader.Create (textReader, settings))
+                    while (xmlReader.Read ()) {}
+            }
+            catch (Exception e)
+            {
+                Message (TraceLevel.Error, "mdoc: {0}", e.ToString ());
+            }
+        }
+
+        void RecurseDirectory (string dir)
+        {
+            string[] files = Directory.GetFiles (dir, "*.xml");
+            foreach (string f in files)
+            {
+                if (IsMonodocFile (f))
+                    ValidateFile (f);
+            }
+
+            string[] dirs = Directory.GetDirectories (dir);
+            foreach (string d in dirs)
+                RecurseDirectory (d);
+        }
+
+        void OnValidationEvent (object sender, ValidationEventArgs a)
+        {
+            errors++;
+            Message (TraceLevel.Error, "mdoc: {0}", a.Message);
+        }
+
+        static bool IsMonodocFile (string file)
+        {
+            var dpath = Path.GetDirectoryName (file);
+            var dname = Path.GetFileName (dpath);
+
+            if (File.Exists (file) && Path.GetExtension (file).ToLower () == ".xml" && !dname.Equals(Consts.FrameworksIndex))
+                return true;
+            else
+                return false;
+
+        }
+    }
+}
+
diff --git a/mdoc/Mono.Documentation/Updater/Frameworks/FrameworkIndex.cs b/mdoc/Mono.Documentation/Updater/Frameworks/FrameworkIndex.cs
index 9d0ae887..e9e19600 100644
--- a/mdoc/Mono.Documentation/Updater/Frameworks/FrameworkIndex.cs
+++ b/mdoc/Mono.Documentation/Updater/Frameworks/FrameworkIndex.cs
@@ -60,7 +60,7 @@ namespace Mono.Documentation.Updater.Frameworks
 			if (string.IsNullOrWhiteSpace (this.path))
 				return;
 			
-			string outputPath = Path.Combine (path, "FrameworksIndex");
+			string outputPath = Path.Combine (path, Consts.FrameworksIndex);
 			if (!Directory.Exists (outputPath))
 				Directory.CreateDirectory (outputPath);
 
diff --git a/mdoc/Mono.Documentation/Updater/XmlSyncer.cs b/mdoc/Mono.Documentation/Updater/XmlSyncer.cs
index 4bc3a40c..dda4cd0e 100644
--- a/mdoc/Mono.Documentation/Updater/XmlSyncer.cs
+++ b/mdoc/Mono.Documentation/Updater/XmlSyncer.cs
@@ -35,7 +35,7 @@ namespace Mono.Documentation.Updater
                 if (addIndex)
                     pe.SetAttribute ("Index", index.ToString ());
                 if (addfx)
-                    pe.SetAttribute ("FrameworkAlternate", fx);
+					pe.SetAttribute (Consts.FrameworkAlternate, fx);
 
                 MakeAttributes (pe, GetCustomAttributes (param.CustomAttributes, ""));
             };
@@ -104,7 +104,7 @@ namespace Mono.Documentation.Updater
 
                                 //-find < parameter where index = currentIndex >
                                 var currentNode = paramNodes[parameterIndex] as XmlElement;
-                                currentNode.SetAttribute ("FrameworkAlternate", fxList);
+                                currentNode.SetAttribute (Consts.FrameworkAlternate, fxList);
 
                                 addParameter (p, parameterNode, ptype, parameterIndex - parameterIndexOffset, true, typeEntry.Framework.Name, true);
                                 parameterIndexOffset++;
@@ -149,7 +149,7 @@ namespace Mono.Documentation.Updater
                 {
                     Element = p,
                     Name = p.GetAttribute ("Name"),
-                    FrameworkAlternate = p.GetAttribute ("FrameworkAlternate")
+                    FrameworkAlternate = p.GetAttribute (Consts.FrameworkAlternate)
                 })
                 .Where (p =>
                         !string.IsNullOrWhiteSpace (p.FrameworkAlternate) &&
@@ -163,11 +163,11 @@ namespace Mono.Documentation.Updater
                     string newValue = FXUtils.RemoveFXFromList (a.FrameworkAlternate, typeEntry.Framework.Name);
                     if (string.IsNullOrWhiteSpace (newValue))
                     {
-                        a.Element.RemoveAttribute ("FrameworkAlternate");
+                        a.Element.RemoveAttribute (Consts.FrameworkAlternate);
                     }
                     else
                     {
-                        a.Element.SetAttribute ("FrameworkAlternate", newValue);
+                        a.Element.SetAttribute (Consts.FrameworkAlternate, newValue);
                     }
                 }
             }
diff --git a/mdoc/Mono.Documentation/validate.cs b/mdoc/Mono.Documentation/validate.cs
deleted file mode 100644
index afaba40f..00000000
--- a/mdoc/Mono.Documentation/validate.cs
+++ /dev/null
@@ -1,123 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO;
-using System.Reflection;
-using System.Xml;
-using System.Xml.Schema;
-
-using Mono.Options;
-
-namespace Mono.Documentation
-{
-	public class MDocValidator : MDocCommand
-	{
-		XmlReaderSettings settings;
-		long errors = 0;
-
-		public override void Run (IEnumerable<string> args)
-		{
-			string[] validFormats = {
-				"ecma",
-			};
-			string format = "ecma";
-			var p = new OptionSet () {
-				{ "f|format=",
-					"The documentation {0:FORMAT} used within PATHS.  " + 
-						"Valid formats include:\n  " +
-						string.Join ("\n  ", validFormats) + "\n" +
-						"If no format provided, `ecma' is used.",
-					v => format = v },
-			};
-			List<string> files = Parse (p, args, "validate", 
-					"[OPTIONS]+ PATHS",
-					"Validate PATHS against the specified format schema.");
-			if (files == null)
-				return;
-			if (Array.IndexOf (validFormats, format) < 0)
-				Error ("Invalid documentation format: {0}.", format);
-			Run (format, files);
-		}
-	
-		public void Run (string format, IEnumerable<string> files)
-		{
-			Stream s = null;
-
-			switch (format) {
-				case "ecma":
-					s = Assembly.GetExecutingAssembly ().GetManifestResourceStream ("monodoc-ecma.xsd");
-					break;
-
-				default:
-					throw new NotSupportedException (string.Format ("The format `{0}' is not suppoted.", format));
-			}
-
-			if (s == null)
-				throw new NotSupportedException (string.Format ("The schema for `{0}' was not found.", format));
-
-			settings = new XmlReaderSettings ();
-			settings.Schemas.Add (XmlSchema.Read (s, null));
-			settings.Schemas.Compile ();
-			settings.ValidationType = ValidationType.Schema;
-			settings.ValidationEventHandler += OnValidationEvent;
-
-			// skip args[0] because it is the provider name
-			foreach (string arg in files) {
-				if (IsMonodocFile (arg))
-					ValidateFile (arg);
-
-				if (Directory.Exists (arg))
-				{
-					RecurseDirectory (arg);
-				}
-			}
-
-			Message (errors == 0 ? TraceLevel.Info : TraceLevel.Error, 
-					"Total validation errors: {0}", errors);
-		}
-
-		void ValidateFile (string file)
-		{
-			try {
-				using (var reader = XmlReader.Create (new XmlTextReader (file), settings)) {
-					while (reader.Read ()) {
-						// do nothing
-					}
-				}
-			}
-			catch (Exception e) {
-				Message (TraceLevel.Error, "mdoc: {0}", e.ToString ());
-			}
-		}
-
-		void RecurseDirectory (string dir)
-		{
-			string[] files = Directory.GetFiles (dir, "*.xml");
-			foreach (string f in files)
-			{
-				if (IsMonodocFile (f))
-					ValidateFile (f);
-			}
-
-			string[] dirs = Directory.GetDirectories (dir);
-			foreach (string d in dirs)
-				RecurseDirectory (d);
-		}
-
-		void OnValidationEvent (object sender, ValidationEventArgs a)
-		{
-			errors ++;
-			Message (TraceLevel.Error, "mdoc: {0}", a.Message);
-		}
-
-		static bool IsMonodocFile (string file)
-		{
-				if (File.Exists (file) && Path.GetExtension (file).ToLower () == ".xml")
-					return true;
-				else
-					return false;
-			
-		}
-	}
-}
-
diff --git a/mdoc/Resources/monodoc-ecma.xsd b/mdoc/Resources/monodoc-ecma.xsd
index 3ae49b62..3a777492 100644
--- a/mdoc/Resources/monodoc-ecma.xsd
+++ b/mdoc/Resources/monodoc-ecma.xsd
@@ -51,6 +51,8 @@ add masterdoc support?
   <xs:attribute name="TypeParamName" type="xs:string" />
   <xs:attribute name="overwrite" type="xs:boolean" />
   <xs:attribute name="supported" type="xs:boolean"/>
+  <xs:attribute name="FrameworkAlternate" type="xs:string"/>
+  <xs:attribute name="Index" type="xs:integer"/>
 
   <!-- define simple elements -->
   <xs:element name="AssemblyName" type="xs:string" />
@@ -116,6 +118,7 @@ add masterdoc support?
         <xs:element ref="ExcludedTypeName" minOccurs="0" />
         <xs:element ref="ExcludedLibraryName" minOccurs="0" />
       </xs:sequence>
+      <xs:attribute name="FrameworkAlternate" use="optional" />
     </xs:complexType>
   </xs:element>
 
@@ -467,6 +470,7 @@ add masterdoc support?
       <xs:attribute ref="Language" />
       <xs:attribute ref="Value" />
       <xs:attribute ref="Usage" />
+      <xs:attribute name="FrameworkAlternate" use="optional" />
     </xs:complexType>
   </xs:element>
 
@@ -622,6 +626,8 @@ add masterdoc support?
       <xs:attribute ref="Name" />
       <xs:attribute ref="Type" />
       <xs:attribute ref="RefType" />
+      <xs:attribute name="Index" use="optional" />
+      <xs:attribute name="FrameworkAlternate" use="optional" />
     </xs:complexType>
   </xs:element>
 
@@ -948,6 +954,8 @@ add masterdoc support?
         <xs:element ref="Constraints" />
       </xs:choice>
       <xs:attribute ref="Name" use="required" />
+      <xs:attribute name="Index" use="optional" />
+      <xs:attribute name="FrameworkAlternate" use="optional" />
     </xs:complexType>
   </xs:element>
 
@@ -967,6 +975,7 @@ add masterdoc support?
       <xs:attribute ref="Value"/>
       <xs:attribute ref="Usage"/>
       <xs:attribute ref="Maintainer" />
+      <xs:attribute name="FrameworkAlternate" use="optional" />
     </xs:complexType>
   </xs:element>
 
diff --git a/mdoc/mdoc.Test/ValidationTests.cs b/mdoc/mdoc.Test/ValidationTests.cs
new file mode 100644
index 00000000..54827d71
--- /dev/null
+++ b/mdoc/mdoc.Test/ValidationTests.cs
@@ -0,0 +1,154 @@
+using Mono.Documentation;

+using NUnit.Framework;
+using System;

+using System.Collections.Generic;

+using System.Linq;

+using System.IO;
+using System.Text;

+using System.Xml;

+
+namespace mdoc.Test
+{
+    [TestFixture ()]
+    public class ValidationTests
+    {

+
+        [Test ()]
+        public void ValidationFailure ()
+        {

+            var context = InitializeTestContext ();

+

+            context.Validator.ValidateFile (new StringReader ("<random></random>"));

+

+            Assert.AreEqual (1, context.Errors.Count);

+            Assert.IsTrue (context.Errors.Any (e => e.Message.Contains ("random")));
+        }

+

+        [Test ()]

+        public void ValidationSuccess ()

+        {

+            var context = InitializeTestContext ();

+

+            context.Validator.ValidateFile (new StringReader ("<Type Name=\"AVKitError\" FullName=\"AVKit.AVKitError\"></Type>"));

+

+            Assert.AreEqual (0, context.Errors.Count);

+        }

+

+        [Test]

+        public void FrameworkAlternate_Attributes_Type ()

+        {

+            string xmlString = @"<Type Name=""AVKitError"" FullName=""AVKit.AVKitError"">

+  <Attributes>

+    <Attribute>

+      <AttributeName>ObjCRuntime.Introduced(ObjCRuntime.PlatformName.iOS, 9, 0, ObjCRuntime.PlatformArchitecture.None, null)</AttributeName>

+    </Attribute>

+    <Attribute FrameworkAlternate=""One;Two"">

+      <AttributeName>ObjCRuntime.Native</AttributeName>

+    </Attribute>

+  </Attributes>

+</Type>";

+

+

+            var context = InitializeTestContext ();

+

+            context.Validator.ValidateFile (new StringReader (xmlString));

+

+

+            Assert.AreEqual (0, context.Errors.Count, context.ErrorText);

+        }

+

+        [Test]

+        public void FrameworkAlternate_MemberSignature ()

+        {

+            string xmlString = @"<Type Name=""blah"" FullName=""blah.blah"">

+            <Members><Member MemberName=""Meth"">

+      <MemberSignature Language=""C#"" Value=""public void Meth (int a, string d, int c);"" FrameworkAlternate=""One;Three"" />

+      <MemberSignature Language=""C#"" Value=""public void Meth (int a, string b, int c);"" FrameworkAlternate=""Two"" />

+      <MemberType>b</MemberType>

+      <Docs></Docs>

+    </Member></Members></Type>";

+

+

+            var context = InitializeTestContext ();

+

+            context.Validator.ValidateFile (new StringReader (xmlString));

+

+

+            Assert.AreEqual (0, context.Errors.Count, context.ErrorText);

+        }

+

+        [Test]

+        public void FrameworkAlternate_TypeSignature ()

+        {

+            string xmlString = @"<Type Name=""blah"" FullName=""blah.blah"">

+      <TypeSignature Language=""C#"" Value=""blah"" FrameworkAlternate=""One;Three"" />

+      <TypeSignature Language=""C#"" Value=""blah2"" FrameworkAlternate=""Two"" />

+</Type>";

+

+

+            var context = InitializeTestContext ();

+

+            context.Validator.ValidateFile (new StringReader (xmlString));

+

+

+            Assert.AreEqual (0, context.Errors.Count, context.ErrorText);

+        }

+

+        [Test]

+        public void FrameworkAlternate_Parameter ()

+        {

+            string xmlString = @"<Member MemberName=""Meth"">

+      <MemberSignature Language=""C#"" Value=""blah"" />

+      <MemberType>Method</MemberType>

+      <Parameters>

+        <Parameter Name = ""a"" Type=""System.Int32"" Index=""0"" FrameworkAlternate=""One"" />

+        <Parameter Name = ""d"" Type=""System.Int32"" Index=""0"" FrameworkAlternate=""Three"" />

+      </Parameters>

+      <Docs></Docs>

+    </Member>";

+

+

+            var context = InitializeTestContext ();

+

+            context.Validator.ValidateFile (new StringReader (xmlString));

+

+

+            Assert.AreEqual (0, context.Errors.Count, context.ErrorText);

+        }

+
+        #region Test Context Stuff

+        struct ValidationContext

+        {

+            public MDocValidator Validator;

+            public List<Exception> Errors;

+            public string ErrorText{

+                get => Errors.Aggregate (

+                    new StringBuilder (),
+                    (sb, e) =>
+                    {
+                        sb.Append (e.Message + ";");
+                        return sb;
+                    }

+                    ).ToString ();

+            }

+        }
+
+        private static ValidationContext InitializeTestContext ()
+        {
+            List<Exception> errors = new List<Exception> ();
+
+            MDocValidator validator = new MDocValidator ();

+            validator.InitializeSchema (

+                "ecma",
+                (a, b) => errors.Add (b.Exception)

+            );

+            ValidationContext context = new ValidationContext

+            {

+                Validator = validator,

+                Errors = errors

+            };
+            return context;
+        }
+        #endregion
+    }
+}
diff --git a/mdoc/mdoc.Test/XmlUpdateTests.cs b/mdoc/mdoc.Test/XmlUpdateTests.cs
index 2ced1283..39f58663 100644
--- a/mdoc/mdoc.Test/XmlUpdateTests.cs
+++ b/mdoc/mdoc.Test/XmlUpdateTests.cs
@@ -443,7 +443,7 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.AreEqual ("Three", attributes[0].GetAttribute ("FrameworkAlternate"));
+            Assert.AreEqual ("Three", attributes[0].GetAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -466,7 +466,7 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsFalse (attributes[0].HasAttribute ("FrameworkAlternate"));
+            Assert.IsFalse (attributes[0].HasAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -492,8 +492,8 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsTrue (attributes[0].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("Three;Two", attributes[0].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[0].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("Three;Two", attributes[0].GetAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -519,8 +519,8 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsTrue (attributes[0].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("One;Three", attributes[0].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[0].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("One;Three", attributes[0].GetAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -558,10 +558,10 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 2);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsFalse (attributes[0].HasAttribute ("FrameworkAlternate"));
+            Assert.IsFalse (attributes[0].HasAttribute (Consts.FrameworkAlternate));
             Assert.AreEqual ("Two", attributes[1].FirstChild.InnerText);
-            Assert.IsTrue (attributes[1].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("Three", attributes[1].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[1].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("Three", attributes[1].GetAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -600,10 +600,10 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 2);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsFalse (attributes[0].HasAttribute ("FrameworkAlternate"));
+            Assert.IsFalse (attributes[0].HasAttribute (Consts.FrameworkAlternate));
             Assert.AreEqual ("Two", attributes[1].FirstChild.InnerText);
-            Assert.IsTrue (attributes[1].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("One", attributes[1].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[1].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("One", attributes[1].GetAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -642,10 +642,10 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 2);
             Assert.AreEqual ("One", attributes[1].FirstChild.InnerText);
-            Assert.IsTrue (attributes[1].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("Two", attributes[1].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[1].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("Two", attributes[1].GetAttribute (Consts.FrameworkAlternate));
             Assert.AreEqual ("Two", attributes[0].FirstChild.InnerText);
-            Assert.IsFalse (attributes[0].HasAttribute ("FrameworkAlternate"));
+            Assert.IsFalse (attributes[0].HasAttribute (Consts.FrameworkAlternate));
 
         }
 
@@ -672,8 +672,8 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsTrue (attributes[0].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("One;Two", attributes[0].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[0].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("One;Two", attributes[0].GetAttribute (Consts.FrameworkAlternate));
         }
 
 
@@ -705,8 +705,8 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsTrue (attributes[0].HasAttribute ("FrameworkAlternate"));
-            Assert.AreEqual ("One;Two", attributes[0].GetAttribute ("FrameworkAlternate"));
+            Assert.IsTrue (attributes[0].HasAttribute (Consts.FrameworkAlternate));
+            Assert.AreEqual ("One;Two", attributes[0].GetAttribute (Consts.FrameworkAlternate));
         }
 
         [Test]
@@ -732,7 +732,7 @@ namespace mdoc.Test
 
             Assert.IsTrue (attributes.Count () == 1);
             Assert.AreEqual ("One", attributes[0].FirstChild.InnerText);
-            Assert.IsFalse (attributes[0].HasAttribute ("FrameworkAlternate"));
+            Assert.IsFalse (attributes[0].HasAttribute (Consts.FrameworkAlternate));
         }
 
         string Normalize(string xml) {
diff --git a/mdoc/mdoc.Test/mdoc.Test.csproj b/mdoc/mdoc.Test/mdoc.Test.csproj
index 9cf223d0..01a8b803 100644
--- a/mdoc/mdoc.Test/mdoc.Test.csproj
+++ b/mdoc/mdoc.Test/mdoc.Test.csproj
@@ -100,6 +100,7 @@
     <Compile Include="VBFormatterTests.cs" />

     <Compile Include="FrameworkAlternateTests.cs" />

     <Compile Include="XmlUpdateTests.cs" />

+    <Compile Include="ValidationTests.cs" />

   </ItemGroup>

   <ItemGroup>

     <None Include="packages.config">

diff --git a/mdoc/mdoc.csproj b/mdoc/mdoc.csproj
index 718bbc07..6c6d229e 100644
--- a/mdoc/mdoc.csproj
+++ b/mdoc/mdoc.csproj
@@ -120,7 +120,7 @@
     <Compile Include="Mono.Documentation\monodocs2slashdoc.cs" />

     <Compile Include="Mono.Documentation\msitomsx.cs" />

     <Compile Include="Mono.Documentation\normalize.cs" />

-    <Compile Include="Mono.Documentation\validate.cs" />

+    <Compile Include="Mono.Documentation\MDocValidator.cs" />

     <Compile Include="Mono.Documentation\webdoc.cs" />

     <Compile Include="Mono.Documentation\XhtmlWriter.cs" />

     <Compile Include="Mono.Documentation\exceptions.cs" />