Improvements

frontmatter/runes.go

@@ -0,0 +1,24 @@
+package frontmatter
+
+import "strings"
+
+// HasRune checks if the file has the frontmatter rune
+func HasRune(file []byte) bool {
+	return strings.HasPrefix(string(file), "---") ||
+		strings.HasPrefix(string(file), "+++") ||
+		strings.HasPrefix(string(file), "{")
+}
+
+// AppendRune appends the frontmatter rune to a file
+func AppendRune(frontmatter []byte, language string) []byte {
+	switch language {
+	case "yaml":
+		return []byte("---\n" + string(frontmatter) + "\n---")
+	case "toml":
+		return []byte("+++\n" + string(frontmatter) + "\n+++")
+	case "json":
+		return frontmatter
+	}
+
+	return frontmatter
+}