Split #r commands to improve error handling

src/Interactive/EditorFeatures/Core/Extensibility/Interactive/ResetInteractive.cs

@@ -104,11 +104,12 @@ internal Task Execute(IInteractiveWindow interactiveWindow, string title)
                 await interactiveEvaluator.SetPathsAsync(referenceSearchPaths, sourceSearchPaths, projectDirectory).ConfigureAwait(true);
             }
 
-            await interactiveWindow.SubmitAsync(new[]
+            var importReferencesCommand = referencePaths.Select(_createReference);
+            var importNamespacesCommand = namespacesToImport.Select(_createImport).Join("\r\n");
+            await interactiveWindow.SubmitAsync(importReferencesCommand.Concat(new[]
             {
-                referencePaths.Select(_createReference).Join("\r\n"),
-                namespacesToImport.Select(_createImport).Join("\r\n")
-            }).ConfigureAwait(true);
+                importNamespacesCommand
+            })).ConfigureAwait(true);
         }
 
         /// <summary>

src/VisualStudio/CSharp/Test/Interactive/Commands/ResetInteractiveTests.cs

@@ -37,9 +37,9 @@ public async void TestResetREPLWithProjectContext()
                 Assert.True(replReferenceCommands.Any(rc => rc.EndsWith(@"ResetInteractiveTestsAssembly.dll""")));
                 Assert.True(replReferenceCommands.Any(rc => rc.EndsWith(@"ResetInteractiveVisualBasicSubproject.dll""")));
 
-                var expectedSubmissions = new List<string> {
-                    string.Join("\r\n", replReferenceCommands) + "\r\n",
-                    string.Join("\r\n", @"using ""ns1"";", @"using ""ns2"";") + "\r\n"};
+                var expectedSubmissions = new List<string>();
+                expectedSubmissions.AddRange(replReferenceCommands.Select(r => r + "\r\n"));
+                expectedSubmissions.Add(string.Join("\r\n", @"using ""ns1"";", @"using ""ns2"";") + "\r\n");
                 AssertResetInteractive(workspace, project, buildSucceeds: true, expectedSubmissions: expectedSubmissions);
 
                 // Test that no submissions are executed if the build fails.