From 9031a7d5d50f303d5a7016cab7a40e7782ca7cdb Mon Sep 17 00:00:00 2001
From: Runxi Yu <me@runxiyu.org>
Date: Thu, 03 Apr 2025 16:02:30 +0800
Subject: [PATCH] HTTP: Make README rendering more composable

---
 readme_to_html.go | 67 +++++++++++++++++++++++++----------------------------

diff --git a/readme_to_html.go b/readme_to_html.go
index 6d7bbbcd3a5bcd88ff6445ce8001c4f344468c3e..e0212e92dcbc0423819c8bac2adb96e8d03d2587 100644
--- a/readme_to_html.go
+++ b/readme_to_html.go
@@ -18,51 +18,46 @@ )
 
 var markdownConverter = goldmark.New(goldmark.WithExtensions(extension.GFM))
 
+// escapeHTML just escapes a string and wraps it in [template.HTML].
+func escapeHTML(s string) template.HTML {
+	return template.HTML(html.EscapeString(s)) //#nosec G203
+}
+
 // renderReadmeAtTree looks for README files in the supplied Git tree and
 // returns its filename and rendered (and sanitized) HTML.
-func renderReadmeAtTree(tree *object.Tree) (readmeFilename string, readmeRenderedSafeHTML template.HTML) {
-	var readmeRenderedUnsafe bytes.Buffer
-	var readmeFile *object.File
-	var readmeFileContents string
-	var err error
-
-	if readmeFile, err = tree.File("README"); err == nil {
-		if readmeFileContents, err = readmeFile.Contents(); err != nil {
-			return "Error fetching README", escapeHTML("Unable to fetch contents of README: " + err.Error())
+func renderReadmeAtTree(tree *object.Tree) (string, template.HTML) {
+	for _, name := range []string{"README", "README.md", "README.org"} {
+		file, err := tree.File(name)
+		if err != nil {
+			continue
 		}
-
-		return "README", template.HTML("<pre>" + html.EscapeString(readmeFileContents) + "</pre>") //#nosec G203
+		contents, err := file.Contents()
+		if err != nil {
+			return "Error fetching README", escapeHTML("Unable to fetch contents of " + name + ": " + err.Error())
+		}
+		return renderReadme([]byte(contents), name)
 	}
+	return "", ""
+}
 
-	if readmeFile, err = tree.File("README.md"); err == nil {
-		if readmeFileContents, err = readmeFile.Contents(); err != nil {
-			return "Error fetching README", escapeHTML("Unable to fetch contents of README: " + err.Error())
-		}
-
-		if err = markdownConverter.Convert(stringToBytes(readmeFileContents), &readmeRenderedUnsafe); err != nil {
+// renderReadme renders and sanitizes README content from a byte slice and filename.
+func renderReadme(data []byte, filename string) (string, template.HTML) {
+	switch strings.ToLower(filename) {
+	case "readme":
+		return "README", template.HTML("<pre>" + html.EscapeString(string(data)) + "</pre>") //#nosec G203
+	case "readme.md":
+		var buf bytes.Buffer
+		if err := markdownConverter.Convert(data, &buf); err != nil {
 			return "Error fetching README", escapeHTML("Unable to render README: " + err.Error())
 		}
-
-		return "README.md", template.HTML(bluemonday.UGCPolicy().SanitizeBytes(readmeRenderedUnsafe.Bytes())) //#nosec G203
-	}
-
-	if readmeFile, err = tree.File("README.org"); err == nil {
-		if readmeFileContents, err = readmeFile.Contents(); err != nil {
-			return "Error fetching README", escapeHTML("Unable to fetch contents of README: " + err.Error())
-		}
-
-		orgHTML, err := org.New().Parse(strings.NewReader(readmeFileContents), readmeFilename).Write(org.NewHTMLWriter())
+		return "README.md", template.HTML(bluemonday.UGCPolicy().SanitizeBytes(buf.Bytes())) //#nosec G203
+	case "readme.org":
+		htmlStr, err := org.New().Parse(strings.NewReader(string(data)), filename).Write(org.NewHTMLWriter())
 		if err != nil {
 			return "Error fetching README", escapeHTML("Unable to render README: " + err.Error())
 		}
-
-		return "README.org", template.HTML(bluemonday.UGCPolicy().Sanitize(orgHTML)) //#nosec G203
+		return "README.org", template.HTML(bluemonday.UGCPolicy().Sanitize(htmlStr)) //#nosec G203
+	default:
+		return filename, template.HTML("<pre>" + html.EscapeString(string(data)) + "</pre>") //#nosec G203
 	}
-
-	return "", ""
-}
-
-// escapeHTML just escapes a string and wraps it in [template.HTML].
-func escapeHTML(s string) template.HTML {
-	return template.HTML(html.EscapeString(s)) //#nosec G203
 }

-- 
2.48.1