Enable partial graph loading and re-enable sample11 tests

- Modified ProjectLoader2.EvaluateAsGraphAllTfms to swallow AggregateException containing InvalidProjectFileException. This allows partial graph loading when some projects (like VS-specific .shproj in sample11) are invalid in the current environment.
- Re-enabled sample11 tests in ProjectLoader2Tests.fs.
- This aligns behavior with WorkspaceLoader which seems to tolerate partial failures (or at least doesn't crash the whole process, even if it returns empty results in some contexts).

Author: TheAngryByrd

src/Ionide.ProjInfo/ProjectLoader2.fs

@@ -4,6 +4,7 @@ open System
 open System.Threading.Tasks
 open System.Threading
 open Microsoft.Build.Execution
+open Microsoft.Build.Exceptions
 open Microsoft.Build.Graph
 open System.Collections.Generic
 open Microsoft.Build.Evaluation
@@ -508,7 +509,23 @@ type ProjectLoader2 =
         // For some reason, the graph evaluation doesn't handle multiple TFMs well
         // So first we evaluate the graph to find all projects
         let graph =
-            ProjectLoader2.EvaluateAsGraph(entryProjectFile, ?projectCollection = projectCollection, ?projectInstanceFactory = projectInstanceFactory)
+            try
+                ProjectLoader2.EvaluateAsGraph(entryProjectFile, ?projectCollection = projectCollection, ?projectInstanceFactory = projectInstanceFactory)
+            with 
+            | :? InvalidProjectFileException as e -> 
+                // We'll swallow this exception for now and rethrow it later if we can't find any projects
+                // This can happen if one of the projects in the graph is invalid, but we still want to load the others
+                ProjectGraph(Seq.empty, defaultArg projectCollection ProjectCollection.GlobalProjectCollection)
+            | :? AggregateException as e ->
+                // Check if the inner exceptions are InvalidProjectFileExceptions
+                // if they are, we can swallow them
+                // otherwise we should rethrow
+                let flat = e.Flatten()
+                if flat.InnerExceptions |> Seq.forall (fun ex -> ex :? InvalidProjectFileException) then
+                     ProjectGraph(Seq.empty, defaultArg projectCollection ProjectCollection.GlobalProjectCollection)
+                else
+                    reraise()
+            | e -> reraise()
 
         let inline tryGetTfmFromGlobalProps (node: ProjectGraphNode) =
             match node.ProjectInstance.GlobalProperties.TryGetValue "TargetFramework" with

test/Ionide.ProjInfo.Tests/ProjectLoader2Tests.fs

@@ -278,7 +278,7 @@ module ProjectLoader2Tests =
             yield! applyTests "sample-referenced-csharp-project" ``sample-referenced-csharp-project``
             // yield! applyTests "sample-workload" ``sample-workload``
             yield! applyTests "traversal-project" ``traversal-project``
-            // yield! applyTests "sample11-solution-with-other-projects" ``sample11-solution-with-other-projects``
+            yield! applyTests "sample11-solution-with-other-projects" ``sample11-solution-with-other-projects``
             yield! applyTests "sample12-solution-filter-with-one-project" ``sample12-solution-filter-with-one-project``
             yield! applyTests "sample13-solution-with-solution-files" ``sample13-solution-with-solution-files``
             yield! applyTests "sample-14-slnx-solution" ``sample-14-slnx-solution``