Fix markdown link replacement: use raw URLs, preserve tooltips, and handle absolute URLs correctly

src/NuGetizer.Tasks/CreatePackage.cs

@@ -237,16 +237,30 @@ void GeneratePackage(Stream output = null)
                     Uri.TryCreate(manifest.Metadata.Repository.Url, UriKind.Absolute, out var uri) &&
                     uri.Host.EndsWith("github.com"))
                 {
-                    // expr to match markdown links. use named groups to capture the link text and url.
-                    linkExpr ??= new Regex(@"\[(?<text>[^\]]+)\]\((?<url>[^)]+)\)", RegexOptions.None);
+                    // expr to match markdown links with optional title. use named groups to capture the link text, url and optional title.
+                    linkExpr ??= new Regex(@"\[(?<text>[^\]]+)\]\((?<url>[^\s)]+)(?:\s+""(?<title>[^""]*)"")?\)", RegexOptions.None);
                     var repoUrl = manifest.Metadata.Repository.Url.TrimEnd('/');
+
+                    // Extract owner and repo from URL for raw.githubusercontent.com format
+                    var repoPath = uri.AbsolutePath.TrimStart('/');
+                    var rawBaseUrl = $"https://raw.githubusercontent.com/{repoPath}";
+
                     replaced = linkExpr.Replace(replaced, match =>
                     {
                         var url = match.Groups["url"].Value;
+                        var title = match.Groups["title"].Value;
+
+                        // Check if the URL is already absolute
                         if (Uri.IsWellFormedUriString(url, UriKind.Absolute))
                             return match.Value;
 
-                        var newUrl = $"{repoUrl}/blob/{manifest.Metadata.Repository.Commit}/{url.TrimStart('/')}";
+                        // Use raw.githubusercontent.com format for proper image display on nuget.org
+                        var newUrl = $"{rawBaseUrl}/{manifest.Metadata.Repository.Commit}/{url.TrimStart('/')}";
+
+                        // Preserve the title if present
+                        if (!string.IsNullOrEmpty(title))
+                            return $"[{match.Groups["text"].Value}]({newUrl} \"{title}\")";
+
                         return $"[{match.Groups["text"].Value}]({newUrl})";
                     });
                 }

src/NuGetizer.Tests/CreatePackageTests.cs

@@ -333,7 +333,114 @@ public void when_readme_has_relativeurl_then_expands_github_url()
 
             var readme = File.ReadAllText(file.Source);
 
-            Assert.Contains("[license](https://github.com/devlooped/nugetizer/blob/9dc2cb5de/license.txt)", readme);
+            Assert.Contains("[license](https://raw.githubusercontent.com/devlooped/nugetizer/9dc2cb5de/license.txt)", readme);
+        }
+
+        [Fact]
+        public void when_readme_has_link_with_tooltip_then_preserves_tooltip()
+        {
+            var content = Path.GetTempFileName();
+            File.WriteAllText(content, "See ![avatar](avatars/user.png \"User Avatar\").");
+            task.Contents = new[]
+            {
+                new TaskItem(content, new Metadata
+                {
+                    { MetadataName.PackageId, task.Manifest.GetMetadata("Id") },
+                    { MetadataName.PackFolder, PackFolderKind.None },
+                    { MetadataName.PackagePath, "readme.md" }
+                }),
+            };
+
+            task.Manifest.SetMetadata("Readme", "readme.md");
+            task.Manifest.SetMetadata("RepositoryType", "git");
+            task.Manifest.SetMetadata("RepositoryUrl", "https://github.com/devlooped/nugetizer");
+            task.Manifest.SetMetadata("RepositorySha", "abc123def");
+
+            createPackage = true;
+            ExecuteTask(out var manifest);
+
+            Assert.NotNull(manifest);
+
+            var file = manifest.Files.FirstOrDefault(f => Path.GetFileName(f.Target) == manifest.Metadata.Readme);
+            Assert.NotNull(file);
+            Assert.True(File.Exists(file.Source));
+
+            var readme = File.ReadAllText(file.Source);
+
+            Assert.Contains("[avatar](https://raw.githubusercontent.com/devlooped/nugetizer/abc123def/avatars/user.png \"User Avatar\")", readme);
+        }
+
+        [Fact]
+        public void when_readme_has_absolute_url_then_does_not_replace()
+        {
+            var content = Path.GetTempFileName();
+            File.WriteAllText(content, "[![badge](https://raw.githubusercontent.com/devlooped/sponsors/main/.github/avatars/user.png \"User\")](https://github.com/user)");
+            task.Contents = new[]
+            {
+                new TaskItem(content, new Metadata
+                {
+                    { MetadataName.PackageId, task.Manifest.GetMetadata("Id") },
+                    { MetadataName.PackFolder, PackFolderKind.None },
+                    { MetadataName.PackagePath, "readme.md" }
+                }),
+            };
+
+            task.Manifest.SetMetadata("Readme", "readme.md");
+            task.Manifest.SetMetadata("RepositoryType", "git");
+            task.Manifest.SetMetadata("RepositoryUrl", "https://github.com/devlooped/nugetizer");
+            task.Manifest.SetMetadata("RepositorySha", "abc123def");
+
+            createPackage = true;
+            ExecuteTask(out var manifest);
+
+            Assert.NotNull(manifest);
+
+            var file = manifest.Files.FirstOrDefault(f => Path.GetFileName(f.Target) == manifest.Metadata.Readme);
+            Assert.NotNull(file);
+            Assert.True(File.Exists(file.Source));
+
+            var readme = File.ReadAllText(file.Source);
+
+            // Should NOT prepend repository URL to absolute URLs
+            Assert.DoesNotContain("https://raw.githubusercontent.com/devlooped/nugetizer/abc123def/https://raw.githubusercontent.com", readme);
+            // Should preserve the original absolute URL
+            Assert.Contains("https://raw.githubusercontent.com/devlooped/sponsors/main/.github/avatars/user.png", readme);
+        }
+
+        [Fact]
+        public void when_readme_has_image_link_then_uses_raw_url()
+        {
+            var content = Path.GetTempFileName();
+            File.WriteAllText(content, "![Image](img/logo.png)");
+            task.Contents = new[]
+            {
+                new TaskItem(content, new Metadata
+                {
+                    { MetadataName.PackageId, task.Manifest.GetMetadata("Id") },
+                    { MetadataName.PackFolder, PackFolderKind.None },
+                    { MetadataName.PackagePath, "readme.md" }
+                }),
+            };
+
+            task.Manifest.SetMetadata("Readme", "readme.md");
+            task.Manifest.SetMetadata("RepositoryType", "git");
+            task.Manifest.SetMetadata("RepositoryUrl", "https://github.com/devlooped/nugetizer");
+            task.Manifest.SetMetadata("RepositorySha", "abc123def");
+
+            createPackage = true;
+            ExecuteTask(out var manifest);
+
+            Assert.NotNull(manifest);
+
+            var file = manifest.Files.FirstOrDefault(f => Path.GetFileName(f.Target) == manifest.Metadata.Readme);
+            Assert.NotNull(file);
+            Assert.True(File.Exists(file.Source));
+
+            var readme = File.ReadAllText(file.Source);
+
+            // Should use raw.githubusercontent.com format for proper image display
+            Assert.Contains("https://raw.githubusercontent.com/devlooped/nugetizer/abc123def/img/logo.png", readme);
+            Assert.DoesNotContain("/blob/", readme);
         }
 
         [Fact]