fix: improve frontmatter parsing

package.json

@@ -179,6 +179,7 @@
     "tslog": "^4.10.2",
     "undici": "^7.18.2",
     "ws": "^8.19.0",
+    "yaml": "^2.8.2",
     "zod": "^4.3.5"
   },
   "optionalDependencies": {

pnpm-lock.yaml

@@ -148,6 +148,9 @@ importers:
       ws:
         specifier: ^8.19.0
         version: 8.19.0
+      yaml:
+        specifier: ^2.8.2
+        version: 2.8.2
       zod:
         specifier: ^4.3.5
         version: 4.3.5

src/agents/skills/frontmatter.ts

@@ -1,5 +1,7 @@
+import JSON5 from "json5";
 import type { Skill } from "@mariozechner/pi-coding-agent";
 
+import { parseFrontmatterBlock } from "../../markdown/frontmatter.js";
 import type {
   ClawdbotSkillMetadata,
   ParsedSkillFrontmatter,
@@ -8,32 +10,8 @@ import type {
   SkillInvocationPolicy,
 } from "./types.js";
 
-function stripQuotes(value: string): string {
-  if (
-    (value.startsWith('"') && value.endsWith('"')) ||
-    (value.startsWith("'") && value.endsWith("'"))
-  ) {
-    return value.slice(1, -1);
-  }
-  return value;
-}
-
 export function parseFrontmatter(content: string): ParsedSkillFrontmatter {
-  const frontmatter: ParsedSkillFrontmatter = {};
+  return parseFrontmatterBlock(content);
-  const normalized = content.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
-  if (!normalized.startsWith("---")) return frontmatter;
-  const endIndex = normalized.indexOf("\n---", 3);
-  if (endIndex === -1) return frontmatter;
-  const block = normalized.slice(4, endIndex);
-  for (const line of block.split("\n")) {
-    const match = line.match(/^([\w-]+):\s*(.*)$/);
-    if (!match) continue;
-    const key = match[1];
-    const value = stripQuotes(match[2].trim());
-    if (!key || !value) continue;
-    frontmatter[key] = value;
-  }
-  return frontmatter;
 }
 
 function normalizeStringList(input: unknown): string[] {
@@ -99,7 +77,7 @@ export function resolveClawdbotMetadata(
   const raw = getFrontmatterValue(frontmatter, "metadata");
   if (!raw) return undefined;
   try {
-    const parsed = JSON.parse(raw) as { clawdbot?: unknown };
+    const parsed = JSON5.parse(raw) as { clawdbot?: unknown };
     if (!parsed || typeof parsed !== "object") return undefined;
     const clawdbot = (parsed as { clawdbot?: unknown }).clawdbot;
     if (!clawdbot || typeof clawdbot !== "object") return undefined;

src/hooks/frontmatter.ts

@@ -1,4 +1,6 @@
 import JSON5 from "json5";
+
+import { parseFrontmatterBlock } from "../markdown/frontmatter.js";
 import type {
   ClawdbotHookMetadata,
   HookEntry,
@@ -7,107 +9,8 @@ import type {
   ParsedHookFrontmatter,
 } from "./types.js";
 
-function stripQuotes(value: string): string {
-  if (
-    (value.startsWith('"') && value.endsWith('"')) ||
-    (value.startsWith("'") && value.endsWith("'"))
-  ) {
-    return value.slice(1, -1);
-  }
-  return value;
-}
-
-/**
- * Extract a multi-line block value from frontmatter lines.
- * Handles indented continuation lines (YAML-style multi-line values).
- *
- * @param lines - All lines in the frontmatter block
- * @param startIndex - Index of the line containing the key
- * @returns The combined multi-line value and the number of lines consumed
- */
-function extractMultiLineValue(
-  lines: string[],
-  startIndex: number,
-): { value: string; linesConsumed: number } {
-  const startLine = lines[startIndex];
-  const match = startLine.match(/^([\w-]+):\s*(.*)$/);
-  if (!match) return { value: "", linesConsumed: 1 };
-
-  const inlineValue = match[2].trim();
-
-  // If there's a value on the same line, return it (single-line case)
-  if (inlineValue) {
-    return { value: inlineValue, linesConsumed: 1 };
-  }
-
-  // Multi-line case: collect indented continuation lines
-  const valueLines: string[] = [];
-  let i = startIndex + 1;
-
-  while (i < lines.length) {
-    const line = lines[i];
-    // Stop if we hit a non-indented line (new key or empty line without indent)
-    if (line.length > 0 && !line.startsWith(" ") && !line.startsWith("\t")) {
-      break;
-    }
-    valueLines.push(line);
-    i++;
-  }
-
-  // Join and trim the multi-line value
-  const combined = valueLines.join("\n").trim();
-  return { value: combined, linesConsumed: i - startIndex };
-}
-
 export function parseFrontmatter(content: string): ParsedHookFrontmatter {
-  const frontmatter: ParsedHookFrontmatter = {};
+  return parseFrontmatterBlock(content);
-  const normalized = content.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
-  if (!normalized.startsWith("---")) return frontmatter;
-  const endIndex = normalized.indexOf("\n---", 3);
-  if (endIndex === -1) return frontmatter;
-  const block = normalized.slice(4, endIndex);
-  const lines = block.split("\n");
-
-  let i = 0;
-  while (i < lines.length) {
-    const line = lines[i];
-    const match = line.match(/^([\w-]+):\s*(.*)$/);
-    if (!match) {
-      i++;
-      continue;
-    }
-
-    const key = match[1];
-    const inlineValue = match[2].trim();
-
-    if (!key) {
-      i++;
-      continue;
-    }
-
-    // Check if this is a multi-line value (no inline value and next line is indented)
-    if (!inlineValue && i + 1 < lines.length) {
-      const nextLine = lines[i + 1];
-      if (nextLine.startsWith(" ") || nextLine.startsWith("\t")) {
-        // Multi-line value
-        const { value, linesConsumed } = extractMultiLineValue(lines, i);
-        if (value) {
-          frontmatter[key] = value;
-        }
-        i += linesConsumed;
-        continue;
-      }
-    }
-
-    // Single-line value
-    const value = stripQuotes(inlineValue);
-    if (value) {
-      frontmatter[key] = value;
-    }
-    i++;
-  }
-
-  return frontmatter;
 }
 
 function normalizeStringList(input: unknown): string[] {
@@ -172,7 +75,6 @@ export function resolveClawdbotMetadata(
   const raw = getFrontmatterValue(frontmatter, "metadata");
   if (!raw) return undefined;
   try {
-    // Use JSON5 to handle trailing commas and other relaxed JSON syntax
     const parsed = JSON5.parse(raw) as { clawdbot?: unknown };
     if (!parsed || typeof parsed !== "object") return undefined;
     const clawdbot = (parsed as { clawdbot?: unknown }).clawdbot;

src/markdown/frontmatter.test.ts

@@ -0,0 +1,44 @@
+import JSON5 from "json5";
+import { describe, expect, it } from "vitest";
+
+import { parseFrontmatterBlock } from "./frontmatter.js";
+
+describe("parseFrontmatterBlock", () => {
+  it("parses YAML block scalars", () => {
+    const content = `---
+name: yaml-hook
+description: |
+  line one
+  line two
+---
+`;
+    const result = parseFrontmatterBlock(content);
+    expect(result.name).toBe("yaml-hook");
+    expect(result.description).toBe("line one\nline two");
+  });
+
+  it("handles JSON5-style multi-line metadata", () => {
+    const content = `---
+name: session-memory
+metadata:
+  {
+    "clawdbot":
+      {
+        "emoji": "disk",
+        "events": ["command:new"],
+      },
+  }
+---
+`;
+    const result = parseFrontmatterBlock(content);
+    expect(result.metadata).toBeDefined();
+
+    const parsed = JSON5.parse(result.metadata ?? "") as { clawdbot?: { emoji?: string } };
+    expect(parsed.clawdbot?.emoji).toBe("disk");
+  });
+
+  it("returns empty when frontmatter is missing", () => {
+    const content = "# No frontmatter";
+    expect(parseFrontmatterBlock(content)).toEqual({});
+  });
+});

src/markdown/frontmatter.ts

@@ -0,0 +1,129 @@
+import YAML from "yaml";
+
+export type ParsedFrontmatter = Record<string, string>;
+
+function stripQuotes(value: string): string {
+  if (
+    (value.startsWith('"') && value.endsWith('"')) ||
+    (value.startsWith("'") && value.endsWith("'"))
+  ) {
+    return value.slice(1, -1);
+  }
+  return value;
+}
+
+function coerceFrontmatterValue(value: unknown): string | undefined {
+  if (value === null || value === undefined) return undefined;
+  if (typeof value === "string") return value.trim();
+  if (typeof value === "number" || typeof value === "boolean") return String(value);
+  if (typeof value === "object") {
+    try {
+      return JSON.stringify(value);
+    } catch {
+      return undefined;
+    }
+  }
+  return undefined;
+}
+
+function parseYamlFrontmatter(block: string): ParsedFrontmatter | null {
+  try {
+    const parsed = YAML.parse(block) as unknown;
+    if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) return null;
+    const result: ParsedFrontmatter = {};
+    for (const [rawKey, value] of Object.entries(parsed as Record<string, unknown>)) {
+      const key = rawKey.trim();
+      if (!key) continue;
+      const coerced = coerceFrontmatterValue(value);
+      if (coerced === undefined) continue;
+      result[key] = coerced;
+    }
+    return result;
+  } catch {
+    return null;
+  }
+}
+
+function extractMultiLineValue(
+  lines: string[],
+  startIndex: number,
+): { value: string; linesConsumed: number } {
+  const startLine = lines[startIndex];
+  const match = startLine.match(/^([\w-]+):\s*(.*)$/);
+  if (!match) return { value: "", linesConsumed: 1 };
+
+  const inlineValue = match[2].trim();
+  if (inlineValue) {
+    return { value: inlineValue, linesConsumed: 1 };
+  }
+
+  const valueLines: string[] = [];
+  let i = startIndex + 1;
+
+  while (i < lines.length) {
+    const line = lines[i];
+    if (line.length > 0 && !line.startsWith(" ") && !line.startsWith("\t")) {
+      break;
+    }
+    valueLines.push(line);
+    i++;
+  }
+
+  const combined = valueLines.join("\n").trim();
+  return { value: combined, linesConsumed: i - startIndex };
+}
+
+function parseLineFrontmatter(block: string): ParsedFrontmatter {
+  const frontmatter: ParsedFrontmatter = {};
+  const lines = block.split("\n");
+  let i = 0;
+
+  while (i < lines.length) {
+    const line = lines[i];
+    const match = line.match(/^([\w-]+):\s*(.*)$/);
+    if (!match) {
+      i++;
+      continue;
+    }
+
+    const key = match[1];
+    const inlineValue = match[2].trim();
+
+    if (!key) {
+      i++;
+      continue;
+    }
+
+    if (!inlineValue && i + 1 < lines.length) {
+      const nextLine = lines[i + 1];
+      if (nextLine.startsWith(" ") || nextLine.startsWith("\t")) {
+        const { value, linesConsumed } = extractMultiLineValue(lines, i);
+        if (value) {
+          frontmatter[key] = value;
+        }
+        i += linesConsumed;
+        continue;
+      }
+    }
+
+    const value = stripQuotes(inlineValue);
+    if (value) {
+      frontmatter[key] = value;
+    }
+    i++;
+  }
+
+  return frontmatter;
+}
+
+export function parseFrontmatterBlock(content: string): ParsedFrontmatter {
+  const normalized = content.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
+  if (!normalized.startsWith("---")) return {};
+  const endIndex = normalized.indexOf("\n---", 3);
+  if (endIndex === -1) return {};
+  const block = normalized.slice(4, endIndex);
+
+  const yamlParsed = parseYamlFrontmatter(block);
+  if (yamlParsed !== null) return yamlParsed;
+  return parseLineFrontmatter(block);
+}