Better GOG ID parsing

Author: erri120

CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com) and this p
 ## [4.7.3](https://github.com/erri120/GameFinder/compare/v4.7.2...v4.7.3) - 2025-06-16
 
 - Heroic: fix parser exception when `buildID` is empty
+- GOG: Better ID parsing
 
 ## [4.7.2](https://github.com/erri120/GameFinder/compare/v4.7.1...v4.7.2) - 2025-05-21
 

src/GameFinder.StoreHandlers.GOG/GOGHandler.cs

@@ -97,15 +97,8 @@ private OneOf<GOGGame, ErrorMessage> ParseSubKey(IRegistryKey gogKey, string sub
                 return new ErrorMessage($"Unable to open {gogKey}\\{subKeyName}");
             }
 
-            if (!subKey.TryGetString("gameID", out var sId))
-            {
-                return new ErrorMessage($"{subKey.GetName()} doesn't have a string value \"gameID\"");
-            }
-
-            if (!long.TryParse(sId, NumberStyles.Integer, CultureInfo.InvariantCulture, out var id))
-            {
-                return new ErrorMessage($"The value \"gameID\" of {subKey.GetName()} is not a number: \"{sId}\"");
-            }
+            var idResult = GetId(subKey, subKeyName);
+            if (idResult.IsT1) return idResult.AsT1;
 
             if (!subKey.TryGetString("gameName", out var name))
             {
@@ -128,7 +121,7 @@ private OneOf<GOGGame, ErrorMessage> ParseSubKey(IRegistryKey gogKey, string sub
             }
 
             var game = new GOGGame(
-                GOGGameId.From(id),
+                GOGGameId.From(idResult.AsT0),
                 name,
                 _fileSystem.FromUnsanitizedFullPath(path),
                 buildId
@@ -141,4 +134,37 @@ private OneOf<GOGGame, ErrorMessage> ParseSubKey(IRegistryKey gogKey, string sub
             return new ErrorMessage(e, $"Exception while parsing registry key {gogKey}\\{subKeyName}");
         }
     }
+
+    private static OneOf<long, ErrorMessage> GetId(IRegistryKey subKey, string subKeyName)
+    {
+        ErrorMessage? subKeyError = null;
+        ErrorMessage? idError = null;
+
+        if (!long.TryParse(subKeyName, CultureInfo.InvariantCulture, out var subKeyId))
+        {
+            subKeyError = new ErrorMessage($"`{subKeyName}` of `{subKey.GetName()}` is not a number!");
+        }
+
+        long id = -1;
+        if (subKey.TryGetString("gameID", out var sID))
+        {
+            if (!long.TryParse(sID, CultureInfo.InvariantCulture, out id))
+            {
+                idError = new ErrorMessage($"The value \"gameID\" of {subKey.GetName()} is not a number: \"{sID}\"");
+            }
+        }
+        else
+        {
+            idError = new ErrorMessage($"{subKey.GetName()} doesn't have a string value \"gameID\"");
+        }
+
+        if (subKeyError.HasValue && idError.HasValue)
+        {
+            return new ErrorMessage($"{subKeyError.Value} | {idError.Value}");
+        }
+
+        if (subKeyError.HasValue && !idError.HasValue) return id;
+        if (!subKeyError.HasValue && idError.HasValue) return subKeyId;
+        return id;
+    }
 }

tests/GameFinder.StoreHandlers.GOG.Tests/Test_ShouldError_InvalidValues.cs

@@ -16,6 +16,6 @@ public void Test_ShouldError_InvalidGameId(IFileSystem fileSystem, InMemoryRegis
         invalidKey.AddValue("gameId", gameId);
 
         var error = handler.ShouldOnlyBeOneError();
-        error.Should().Be($"The value \"gameID\" of {invalidKey.GetName()} is not a number: \"{gameId}\"");
+        error.Message.Should().EndWith($"The value \"gameID\" of {invalidKey.GetName()} is not a number: \"{gameId}\"");
     }
 }

tests/GameFinder.StoreHandlers.GOG.Tests/Test_ShouldError_MissingValues.cs

@@ -8,17 +8,6 @@ namespace GameFinder.StoreHandlers.GOG.Tests;
 
 public partial class GOGTests
 {
-    [Theory, AutoFileSystem]
-    public void Test_ShouldError_MissingGameId(IFileSystem fileSystem, InMemoryRegistry registry, string keyName)
-    {
-        var (handler, gogKey) = SetupHandler(fileSystem, registry);
-
-        var invalidKey = gogKey.AddSubKey(keyName);
-
-        var error = handler.ShouldOnlyBeOneError();
-        error.Should().Be($"{invalidKey.GetName()} doesn't have a string value \"gameID\"");
-    }
-
     [Theory, AutoFileSystem]
     public void Test_ShouldError_MissingGameName(IFileSystem fileSystem, InMemoryRegistry registry, string keyName, long gameId)
     {