Snippets5000: Fix case where file deleted and folder contains 1 code file (#535)

* Fix case where file del and folder contains 1 code file

* Add test case

Author: adegeo

snippets5000/PullRequestSimulations/data.json

@@ -59,6 +59,21 @@
       }
     ]
   },
+  {
+    "Name": "Delete - Single file remains no project - Compile",
+    "ExpectedResults": [
+      {
+        "ResultCode": 0,
+        "DiscoveredProject": "snippets/good/normal/single_code_file/Now.cs"
+      }
+    ],
+    "Items": [
+      {
+        "ItemType": "Delete",
+        "Path": "snippets/good/normal/single_code_file/OtherFile.cs"
+      }
+    ]
+  },
   {
     "Name": "Delete - Files from diff projs, find sln",
     "ExpectedResults": [

snippets5000/Snippets5000/PullRequestProcessor.cs

@@ -131,7 +131,7 @@ private async IAsyncEnumerable<DiscoveryResult> FindAllSolutionsAndProjects(stri
             /* SLN found no projs      */ (not null,    1,     0,     _,     _, false, _,         _)    => new DiscoveryResult(DiscoveryResult.RETURN_SLN_NOPROJ, item, project),
             /* SLN found no projs, del */ (not null,    1,     0,     _,     _,  true, _,         _)    => new DiscoveryResult(DiscoveryResult.RETURN_GOOD, item, project),
             /* Project found           */ (not null,    0,     1,     _,     _,     _, _,         _)    => new DiscoveryResult(DiscoveryResult.RETURN_GOOD, item, project),
-            /* Single .cs file compile */ (null,        0,     0,     1,     _,     _, _,         true) => new DiscoveryResult(DiscoveryResult.RETURN_GOOD, item, item),
+            /* Single .cs file compile */ (not null,    0,     0,     1,     _,     _, _,         true) => new DiscoveryResult(DiscoveryResult.RETURN_GOOD, item, project),
             /* Code no proj            */ (null,        0,     0,   > 0,     _,     _, _,         _)    => new DiscoveryResult(DiscoveryResult.RETURN_NOPROJ, item, ""),
             /* Code no proj            */ (null,        0,     0,     _,   > 0,     _, _,         _)    => new DiscoveryResult(DiscoveryResult.RETURN_NOPROJ, item, ""),
             /* catch all               */ _                                                             => new DiscoveryResult(DiscoveryResult.RETURN_NOPROJ, item, "CONDITION NOT FOUND"),
@@ -231,8 +231,18 @@ static void ScanFile(string file, ref string? project, ref int countOfSln, ref i
 
             // If a code file
             else if (EnvExtensionsCodeTriggers.Contains(ext, StringComparer.OrdinalIgnoreCase))
+            {
                 countOfCode++;
 
+                // Case for .NET 10 single file app
+                // No solution or projects found, process a C# file
+                if (countOfSln == 0 && countOfProjs == 0 && ext.Equals(".cs", StringComparison.OrdinalIgnoreCase))
+                {
+                    // First code file can be a project, anything else is invalid
+                    project = countOfCode == 1 ? file : null;
+                }
+            }
+
             // If a special trigger file
             else if (EnvFileTriggers.Contains(Path.GetFileName(file), StringComparer.OrdinalIgnoreCase))
                 countOfSpecial++;