Initial commit

src/index.ts

@@ -0,0 +1,61 @@
+import YAML from "yaml";
+const FRONTMATTER_REGEX = /^---[\s\S]*?---/gm;
+
+/**
+ * Parse a markdown document with optional YAML frontmatter into an object
+ * with the markdown content and any frontmatter as keys.
+ * @param content The raw markdown content
+ * @param markdownKey The key to use for the markdown content
+ * @returns The parsed markdown content and frontmatter
+ */
+function parse(
+  content: string,
+  markdownKey = "content",
+): Record<string, unknown> {
+  const markdown = content.trim().replace(FRONTMATTER_REGEX, "").trim();
+  let frontmatter: Record<string, unknown> = {};
+
+  if (FRONTMATTER_REGEX.test(content)) {
+    const frontmatterString = content.match(FRONTMATTER_REGEX)?.[0] ?? "";
+    const cleanFrontmatter = frontmatterString.replaceAll("---", "").trim();
+    frontmatter = YAML.parse(cleanFrontmatter);
+  }
+
+  return {
+    [markdownKey]: markdown,
+    ...frontmatter,
+  };
+}
+
+/**
+ * Serialize an object with markdown content and optional frontmatter into a
+ * Markdown document. Uses the `content` key for the markdown content by default.
+ * @param data The object to serialize
+ * @param markdownKey The key to use for the markdown content
+ * @returns The parsed markdown content and frontmatter
+ */
+function stringify(
+  data: Record<string, unknown>,
+  markdownKey = "content",
+): string {
+  const markdown = String(data[markdownKey] ?? "");
+  const frontmatter = { ...data };
+  delete frontmatter[markdownKey];
+
+  const remainingKeys = Object.keys(frontmatter).length;
+
+  if (remainingKeys === 0) {
+    return markdown;
+  }
+
+  const stringifiedFrontmatter = YAML.stringify(frontmatter).trim();
+
+  return `---\n${stringifiedFrontmatter}\n---\n${markdown}`;
+}
+
+const EMDY = {
+  parse,
+  stringify,
+} as const;
+
+export default EMDY;