From e50e24d4545f8c9c918423812131ea0f9b67cd20 Mon Sep 17 00:00:00 2001
From: George Vanburgh <1670176+georgevanburgh@users.noreply.github.com>
Date: Fri, 24 Jun 2022 08:37:05 +0100
Subject: [PATCH] Add some more Roslyn generated file suffixes (#1352)

Add some more Roslyn generated file suffixes
---
 .../Helpers/InstrumentationHelper.cs          | 32 ++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/coverlet.core/Helpers/InstrumentationHelper.cs b/src/coverlet.core/Helpers/InstrumentationHelper.cs
index 70dd7b6..a953273 100644
--- a/src/coverlet.core/Helpers/InstrumentationHelper.cs
+++ b/src/coverlet.core/Helpers/InstrumentationHelper.cs
@@ -178,12 +178,13 @@ namespace Coverlet.Core.Helpers
                 Document document = metadataReader.GetDocument(docHandle);
                 string docName = _sourceRootTranslator.ResolveFilePath(metadataReader.GetString(document.Name));
                 Guid languageGuid = metadataReader.GetGuid(document.Language);
+
                 // We verify all docs and return false if not all are present in local
                 // We could have false negative if doc is not a source
                 // Btw check for all possible extension could be weak approach
                 // We exlude from the check the autogenerated source file(i.e. source generators)
                 // We exclude special F# construct https://github.com/coverlet-coverage/coverlet/issues/1145
-                if (!_fileSystem.Exists(docName) && !docName.EndsWith(".g.cs") &&
+                if (!_fileSystem.Exists(docName) && !IsGeneratedDocumentName(docName) &&
                     !IsUnknownModuleInFSharpAssembly(languageGuid, docName))
                 {
                     return (false, docName);
@@ -449,6 +450,35 @@ namespace Coverlet.Core.Helpers
             }
         }
 
+        // Follow the same rules that exist in Microsoft.CodeAnalysis
+        // https://sourceroslyn.io/#Microsoft.CodeAnalysis/InternalUtilities/GeneratedCodeUtilities.cs,55bff725ec9f1338,references
+        private static bool IsGeneratedDocumentName(string docPath)
+        {
+            if (!string.IsNullOrEmpty(docPath))
+            {
+                string fileName = Path.GetFileName(docPath);
+                if (fileName.StartsWith("TemporaryGeneratedFile_", StringComparison.OrdinalIgnoreCase))
+                {
+                    return true;
+                }
+
+                string extension = Path.GetExtension(fileName);
+                if (!string.IsNullOrEmpty(extension))
+                {
+                    string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(docPath);
+                    if (fileNameWithoutExtension.EndsWith(".designer", StringComparison.OrdinalIgnoreCase) ||
+                        fileNameWithoutExtension.EndsWith(".generated", StringComparison.OrdinalIgnoreCase) ||
+                        fileNameWithoutExtension.EndsWith(".g", StringComparison.OrdinalIgnoreCase) ||
+                        fileNameWithoutExtension.EndsWith(".g.i", StringComparison.OrdinalIgnoreCase))
+                    {
+                        return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+
         private static bool IsUnknownModuleInFSharpAssembly(Guid languageGuid, string docName)
         {
             // https://github.com/dotnet/runtime/blob/main/docs/design/specs/PortablePdb-Metadata.md#document-table-0x30