Added capability to show obsolete members in diff with message

Data/ApiDiff.cs

@@ -31,8 +31,9 @@ public class NamespaceDiffInfo : DiffInfo
         {
             public string Namespace;
             public List<TypeDiffInfo> Types = new List<TypeDiffInfo> ();
-            public int NumAdditions => Types.Sum(x => x.NumAdditions);
-            public int NumRemovals => Types.Sum(x => x.NumRemovals);
+            public int NumAdditions => Types.Sum (x => x.NumAdditions);
+            public int NumRemovals => Types.Sum (x => x.NumRemovals);
+            public int NumObsolete => Types.Sum (x => x.NumObsolete);
         }
 
         public class TypeDiffInfo : DiffInfo
@@ -43,18 +44,37 @@ public class TypeDiffInfo : DiffInfo
             public int NumAdditions {
                 get {
                     switch (Action) {
-                        case ListDiffActionType.Remove: return 0;
-                        case ListDiffActionType.Update: return Members.Sum(x => x.NumAdditions);
-                        default: return 1 + Members.Sum(x => x.NumAdditions);
+                        case ListDiffActionType.Remove:
+                            return 0;
+                        case ListDiffActionType.Update:
+                            return Members.Sum (x => x.NumAdditions);
+                        default:
+                            return 1 + Members.Sum (x => x.NumAdditions);
                     }
                 }
             }
             public int NumRemovals {
                 get {
                     switch (Action) {
-                        case ListDiffActionType.Remove: return 1;
-                        case ListDiffActionType.Update: return Members.Sum(x => x.NumRemovals);
-                        default: return 0;
+                        case ListDiffActionType.Remove:
+                            return 1;
+                        case ListDiffActionType.Update:
+                            return Members.Sum (x => x.NumRemovals);
+                        default:
+                            return 0;
+                    }
+                }
+            }
+
+            public int NumObsolete {
+                get {
+                    switch (Action) {
+                        case ListDiffActionType.Remove:
+                            return 0;
+                        case ListDiffActionType.Update:
+                            return Members.Sum (x => x.NumObsolete);
+                        default:
+                            return 0;
                     }
                 }
             }
@@ -65,6 +85,8 @@ public class MemberDiffInfo : DiffInfo
             public IMemberDefinition Member;
             public int NumAdditions => Action == ListDiffActionType.Add ? 1 : 0;
             public int NumRemovals => Action == ListDiffActionType.Remove ? 1 : 0;
+            public int NumObsolete;
+            public string ObsoleteMessage;
         }
 
         public ApiDiff (PackageData package, PackageTargetFramework framework, PackageData otherPackage, PackageTargetFramework otherFramework)
@@ -128,6 +150,8 @@ public ApiDiff (PackageData package, PackageTargetFramework framework, PackageDa
                             break;
                     }
 
+
+
                     if (ta.ActionType == ListDiffActionType.Remove) {
                         types.Add (ti);
                         continue;
@@ -146,6 +170,13 @@ public ApiDiff (PackageData package, PackageTargetFramework framework, PackageDa
                                 break;
                             default:
                                 mi.Member = ma.DestinationItem;
+
+                                var (isObsolete, obsoleteMessage) = mi.Member.GetObsoleteMessage ();
+                                if (isObsolete) {
+                                    mi.NumObsolete++;
+                                    mi.ObsoleteMessage = obsoleteMessage;
+                                    ti.Members.Add (mi);
+                                }
                                 break;
                         }
                     }
@@ -175,14 +206,14 @@ public static async Task<ApiDiff> GetAsync (
             var otherVersion = versions.GetVersion (inputOtherVersion);
             var framework = (inputFramework ?? "").ToString ().ToLowerInvariant ().Trim ();
 
-            return await cache.GetAsync(
+            return await cache.GetAsync (
                     Tuple.Create (versions.LowerId, version.ShortVersionString, framework),
                     otherVersion.ShortVersionString,
                     httpClient,
                     token)
                 .ConfigureAwait (false);
         }
-
+        
         class ApiDiffCache : DataCache<Tuple<string, string, string>, string, ApiDiff>
         {
             public ApiDiffCache () : base (TimeSpan.FromDays (1)) { }

Data/AttributeExtensions.cs

@@ -0,0 +1,22 @@
+using System.Linq;
+using Mono.Cecil;
+
+namespace FuGetGallery
+{
+    internal static class AttributeExtensions
+    {
+        internal static (bool, string) GetObsoleteMessage (this ICustomAttributeProvider attributeProvider)
+        {
+            if (!attributeProvider.HasCustomAttributes)
+                return (false, null);
+
+            var obsoleteAttrribute =
+                attributeProvider.CustomAttributes.FirstOrDefault (ca =>
+                    ca.AttributeType.FullName == "System.ObsoleteAttribute");
+
+            return obsoleteAttrribute != null
+                ? (true, obsoleteAttrribute.ConstructorArguments.FirstOrDefault ().Value?.ToString ())
+                : (false, null);
+        }
+    }
+}

Data/CecilExtensions.cs

@@ -65,7 +65,7 @@ public static string GetXmlName (this IMemberDefinition member)
             return Mono.Cecil.Rocks.DocCommentId.GetDocCommentId (member);
         }
 
-        static void WriteEncoded (string s, TextWriter w)
+        public static void WriteEncoded (string s, TextWriter w)
         {
             for (var i = 0; i < s.Length; i++) {
                 switch (s[i]) {

Data/TypeDocumentation.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.IO.Compression;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Text.RegularExpressions;
@@ -13,7 +12,6 @@
 using ICSharpCode.Decompiler.CSharp;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.Decompiler.CSharp.Resolver;
-using ICSharpCode.Decompiler.CSharp.OutputVisitor;
 using System.Xml.Linq;
 using System.Text;
 using ICSharpCode.Decompiler.TypeSystem.Implementation;
@@ -86,10 +84,20 @@ void WriteDocumentation (TextWriter w)
                 var xmlName = m.GetXmlName ();
                 MemberXmlDocs mdocs = null;
                 xmlDocs?.GetLanguage(languageCode).MemberDocs.TryGetValue (xmlName, out mdocs);
+                var (isObsolete, obsoleteMessage) = m.GetObsoleteMessage ();
+                if (isObsolete && obsoleteMessage == null) {
+                    obsoleteMessage = m.Name + " is obsolete";
+                }
 
                 w.WriteLine ("<div class='member-code'>");
                 m.WritePrototypeHtml (w, framework: framework, mdocs, linkToCode: true, isExtensionClass);
                 w.WriteLine ("</div>");
+
+                if (isObsolete) {
+                    w.Write ("<div class='member-obsolete'><b>Obsolete:</b> ");
+                    CecilExtensions.WriteEncoded (obsoleteMessage, w);
+                    w.Write ("</div>");
+                }
 
                 w.WriteLine ("<p>");
                 if (mdocs != null) {

Pages/packages/details.cshtml

@@ -343,12 +343,15 @@
         <p>@diff.Error</p>
     }
     <p>
-        <span class="diff-Add">
+        <span class="diff-Add" style="margin-right:0.5em;">
             <strong>@diff.Namespaces.Sum(ni => ni.NumAdditions)</strong> Additions
         </span>
-        <span class="diff-Remove" style="margin:0.5em;">
+        <span class="diff-Remove"style="margin-right:0.5em;">
             <strong>@diff.Namespaces.Sum(ni => ni.NumRemovals)</strong> Removals
         </span>
+        <span class="diff-Obsolete">
+            <strong>@diff.Namespaces.Sum(ni => ni.NumObsolete)</strong> Obsolete
+        </span>
     </p>
     @foreach (var ni in diff.Namespaces)
     {
@@ -362,7 +365,13 @@
                     <ul class="diff-Members">
                         @foreach (var mi in ti.Members)
                         {
-                            <li class="[email protected] diff-Member"><span class="inline-code">@Html.Raw(mi.Member.GetPrototypeHtml(framework: ti.Framework, null, linkToCode: false, isExtensionClass))</span></li>
+                            <li class="[email protected] diff-Member @(mi.NumObsolete > 0 ? "diff-Obsolete" : "")">
+                                <span class="inline-code">@Html.Raw(mi.Member.GetPrototypeHtml(framework: ti.Framework, null, linkToCode: false, isExtensionClass))</span>
+                                @if (!string.IsNullOrWhiteSpace(mi.ObsoleteMessage))
+                                {
+                                    <p style="margin-top: 1em; margin-bottom: 0em;">@mi.ObsoleteMessage</p>
+                                }
+                            </li>
                         }
                     </ul>
                 </li>

Startup.cs

@@ -23,12 +23,12 @@ public Startup(IConfiguration configuration)
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
-            try {
-                new Database ().MigrateAsync ().Wait ();
-                services.AddScoped<Database, Database> ();
+            try {
+                new Database ().MigrateAsync ().Wait ();
+                services.AddScoped<Database, Database> ();
             }
-            catch (Exception dbex) {
-                Console.WriteLine ($"Failed to open the database: {dbex}");
+            catch (Exception dbex) {
+                Console.WriteLine ($"Failed to open the database: {dbex}");
             }
             services.AddControllers();
             services.AddRazorPages(options =>