Fix release notes that stay empty after a repository change, rel_ tags and npm author parsing

src/backend/PkgDiff.Application/Services/PackageCacheService.cs

@@ -233,11 +233,27 @@ private async Task<PackageMetadata> BuildMetadataFromCache(CachedPackage cached,
         };
     }
 
+    private async Task ForgetEmptyReleaseNotesAsync(int cachedPackageId, string registry, string packageId)
+    {
+        var emptyNotes = (await _unitOfWork.CachedReleaseNotes
+            .FindAsync(rn => rn.CachedPackageId == cachedPackageId && rn.IsEmpty && rn.ReleaseNotesSource != null))
+            .ToList();
+        if (emptyNotes.Count == 0)
+            return;
+
+        foreach (var note in emptyNotes)
+            note.ReleaseNotesSource = null;
+        await _unitOfWork.SaveChangesAsync();
+
+        _jobs.Enqueue<IPackageAnalysisService>(service => service.ScrapePackageReleaseNotesAsync(packageId, registry));
+    }
+
     private async Task SaveFreshMetadataToCache(
         CachedPackage? cached, PackageMetadata metadata, string registry, string packageId)
     {
         var registryId = await ResolveRegistryIdAsync(registry);
 
+        var repositoryChanged = false;
         if (cached == null)
         {
             cached = new CachedPackage
@@ -263,6 +279,8 @@ private async Task SaveFreshMetadataToCache(
             cached.Authors = metadata.Authors;
             cached.IconUrl = metadata.IconUrl;
             cached.ProjectUrl = metadata.ProjectUrl;
+            repositoryChanged = metadata.GitHubRepositoryUrl != null
+                && !string.Equals(metadata.GitHubRepositoryUrl, cached.GitHubRepositoryUrl, StringComparison.OrdinalIgnoreCase);
             // A repository found while scraping release notes is kept when the registry names none
             cached.GitHubRepositoryUrl = metadata.GitHubRepositoryUrl ?? cached.GitHubRepositoryUrl;
             cached.AllVersionsJson = JsonSerializer.Serialize(metadata.Versions.Select(v => v.Version));
@@ -273,6 +291,9 @@ private async Task SaveFreshMetadataToCache(
 
         await _unitOfWork.SaveChangesAsync();
 
+        if (repositoryChanged)
+            await ForgetEmptyReleaseNotesAsync(cached.Id, registry.ToLowerInvariant(), packageId);
+
         var latestVersion = metadata.LatestVersion ?? string.Empty;
         var latestPublished = metadata.Versions.FirstOrDefault(v => v.Version == latestVersion)?.PublishedDate;
         await _liveUpdates.RecordLatestVersionAsync(cached, registry, latestVersion, latestPublished, authoritative: true);

src/backend/PkgDiff.Infrastructure/Services/GitHubScraperService.cs

@@ -336,6 +336,7 @@ private static IEnumerable<string> TagCandidates(string? packageId, string versi
         }
         yield return $"release-{version}";
         yield return $"release/{version}";
+        yield return $"rel_{version.Replace('.', '_')}";
     }
 
     [System.Text.RegularExpressions.GeneratedRegex(@"^[vV]?\d")]

src/backend/PkgDiff.Infrastructure/Services/NpmService.cs

@@ -265,7 +265,7 @@ private class NpmAuthorConverter : JsonConverter<NpmAuthor>
                         var propName = reader.GetString();
                         reader.Read();
                         if (propName == "name") author.Name = reader.GetString();
-                        else reader.Skip();
+                        else reader.TrySkip();
                     }
                 }
                 return author;
@@ -299,7 +299,7 @@ private class NpmRepositoryConverter : JsonConverter<NpmRepository>
                 return new NpmRepository { Url = reader.GetString() };
             if (reader.TokenType != JsonTokenType.StartObject)
             {
-                reader.Skip();
+                reader.TrySkip();
                 return null;
             }
 
@@ -312,7 +312,7 @@ private class NpmRepositoryConverter : JsonConverter<NpmRepository>
                 reader.Read();
                 var value = reader.TokenType == JsonTokenType.String ? reader.GetString() : null;
                 if (reader.TokenType is JsonTokenType.StartObject or JsonTokenType.StartArray)
-                    reader.Skip();
+                    reader.TrySkip();
                 switch (propName)
                 {
                     case "type": repository.Type = value; break;
@@ -349,11 +349,11 @@ private class LooseStringConverter : JsonConverter<string?>
                         if (reader.TokenType == JsonTokenType.String)
                             first ??= reader.GetString();
                         else if (reader.TokenType is JsonTokenType.StartObject or JsonTokenType.StartArray)
-                            reader.Skip();
+                            reader.TrySkip();
                     }
                     return first;
                 case JsonTokenType.StartObject:
-                    reader.Skip();
+                    reader.TrySkip();
                     return null;
                 default:
                     return null;