parseFrontmatter (utils/frontmatter.ts)

Parses and serializes YAML frontmatter in markdown, sanitizing values.

// Source: https://github.com/first-fluke/oh-my-agent | License: MIT | Copyright 2026 Eunkwang Shin, Gahyun Kim
// Provided via justclaw.it.com; keep this notice with the code.
import { parse as parseYaml, stringify as stringifyYaml } from "yaml";
import { isRecord } from "./type-guards.js";

export interface ParsedFrontmatter {
  frontmatter: Record<string, unknown>;
  body: string;
}

function sanitizeFrontmatterValue(value: unknown): unknown {
  if (value === undefined || value === null) return undefined;

  if (Array.isArray(value)) {
    return value
      .map((item) => sanitizeFrontmatterValue(item))
      .filter((item) => item !== undefined);
  }

  if (isRecord(value)) {
    return Object.fromEntries(
      Object.entries(value)
        .map(([key, item]) => [key, sanitizeFrontma

... (truncated -- full source via MCP)