Improve the API diff logic a bit more

build.cake

@@ -1,9 +1,7 @@
 #addin nuget:?package=Cake.Xamarin&version=2.0.1
 #addin nuget:?package=Cake.XCode&version=3.0.0
 #addin nuget:?package=Cake.FileHelpers&version=2.0.0
-#addin nuget:?package=Cake.MonoApiTools&version=2.0.0
-
-#tool nuget:?package=Cake.MonoApiTools&version=2.0.0
+#addin nuget:https://ci.appveyor.com/nuget/cake-monoapitools-gunq9ba46ljl?package=Cake.MonoApiTools&version=2.0.0-preview2
 
 #reference "tools/SharpCompress/lib/net45/SharpCompress.dll"
 #reference "tools/Newtonsoft.Json/lib/net45/Newtonsoft.Json.dll"
@@ -380,10 +378,18 @@ Task ("nuget")
 Task ("api-diff")
     .Does (() =>
 {
+    var ids = new List<string> {
+        "skiasharp",
+        // "skiasharp.views",
+        // "skiasharp.views.forms",
+        // "harfbuzzsharp",
+        // "skiasharp.harfbuzz",
+    };
+
     try {
 
-    var nuget = "SkiaSharp";
-    var pathToAssembly = "lib/netstandard1.3/SkiaSharp.dll";
+    foreach (var nuget in ids) {
+        Information ($"Comparing the assemblies in '{nuget}'...");
 
         // find the latest version for this id
         var version = "0.0";
@@ -396,7 +402,7 @@ Task ("api-diff")
         }
 
         // download nugets
-        var tempPath = $"./externals/api-diff/{nuget}";
+        var tempPath = $"./externals/api-diff/{nuget}.{version}";
         var oldDest = $"{tempPath}/{nuget}.{version}.nupkg";
         if (!FileExists (oldDest)) {
             CleanDirectories (tempPath);
@@ -407,16 +413,43 @@ Task ("api-diff")
             Unzip (oldDest, tempPath);
         }
 
-        // run the diff
+        // find the dlls
+        var oldDlls = GetFiles ($"{tempPath}/lib/*/*.dll");
+        var newDlls = GetFiles ($"./output/{nuget}/nuget/lib/*/*.dll");
+        var oldPlatforms = oldDlls.Select (p => $"{p.GetDirectory ().GetDirectoryName ()}/{p.GetFilename ()}".ToLower ()).ToArray ();
+        var newPlatforms = newDlls.Select (p => $"{p.GetDirectory ().GetDirectoryName ()}/{p.GetFilename ()}".ToLower ()).ToArray ();
+        var missing = oldPlatforms.Except (newPlatforms);
+        foreach (var miss in missing) {
+            Warning ($"The '{miss}' dll is missing from the new '{nuget}' package.");
+        }
+        var added = newPlatforms.Except (oldPlatforms);
+        foreach (var add in added) {
+            Warning ($"The '{add}' dll was added to the new '{nuget}' package.");
+        }
+        var intersection = newPlatforms.Intersect (oldPlatforms);
+
+        // run the diff on each dll
         var outPath = $"./output/{nuget}/api-diff";
-        var oldApi = $"{outPath}/{nuget}.api-info.old.xml";
-        var newApi = $"{outPath}/{nuget}.api-info.new.xml";
         EnsureDirectoryExists (outPath);
         CleanDirectories (outPath);
-        MonoApiInfo ($"{tempPath}/{pathToAssembly}", oldApi);
-        MonoApiInfo ($"./output/{nuget}/nuget/{pathToAssembly}", newApi);
-        MonoApiDiff (oldApi, newApi, $"{outPath}/{nuget}.api-info.diff.xml");
-        MonoApiHtml (oldApi, newApi, $"{outPath}/{nuget}.api-info.diff.html");
+        foreach (var match in intersection) {
+            Information ($"Comparing the '{match}' assembly...");
+
+            var assembly = (FilePath)$"{outPath}/{match}";
+            EnsureDirectoryExists (assembly.GetDirectory ());
+
+            var oldApi = $"{outPath}/{match}.api-info.old.xml";
+            var newApi = $"{outPath}/{match}.api-info.new.xml";
+
+            var pathToAssembly = $"lib/{match}";
+            MonoApiInfo ($"{tempPath}/{pathToAssembly}", oldApi);
+            MonoApiInfo ($"./output/{nuget}/nuget/{pathToAssembly}", newApi);
+
+            MonoApiDiff (oldApi, newApi, $"{outPath}/{match}.api-info.diff.xml");
+            MonoApiHtmlColorized (oldApi, newApi, $"{outPath}/{match}.api-info.diff.html");
+            MonoApiMarkdownColorized (oldApi, newApi, $"{outPath}/{match}.api-info.diff.md");
+        }
+    }
 
     } catch (AggregateException ex) {
         Error ("{0}", ex.InnerException);