afv-library/scripts/validate-skills.ts
Jasmine Kaur a95d0d3f82
fix: allow nested YAML lists in metadata sub-keys (sync with internal) @W-23173617@ (#298)
fix: allow nested YAML lists in metadata sub-keys (sync with internal)

The validator incorrectly rejected skills with list-type fields (e.g.
cliTools) nested under metadata sub-keys. This syncs the
parseMetadataBlock() fix from sf-skills-internal that distinguishes
direct-child lists from nested ones.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-06-25 20:33:56 +05:30

628 lines
22 KiB
TypeScript

#!/usr/bin/env tsx
// Validates the skills/ directory structure and SKILL.md format.
// Exits with code 1 if any violations are found.
//
// Usage:
// npm run validate:skills # validate all skills
// npm run validate:skills -- --changed --base=origin/main # validate only skills changed vs base
import { execSync } from "child_process"
import fs from "fs"
import path from "path"
import { parseArgs } from "util"
import yaml from "js-yaml"
const SKILLS_DIR = path.join(__dirname, "..", "skills")
/** Parsed context for a single skill directory, built before content checks run. */
interface SkillContext {
dirName: string
dirPath: string
content: string
/** YAML source between `---` lines; `null` if the block is missing. */
rawFrontmatter: string | null
frontmatter: Record<string, string> | null
body: string
}
/** Return value of every check function. */
interface CheckResult {
errors: string[]
/** When true and errors is non-empty, skip remaining checks for this entry. */
fatal?: boolean
/** Defaults to "error". Warnings are printed but do not cause a non-zero exit code. */
severity?: "error" | "warning"
}
/** Collected results for a single skill entry. */
interface SkillResult {
errors: string[]
warnings: string[]
}
/** Runs before SKILL.md is read — validates directory layout. */
interface StructureCheck {
description: string
run(dirName: string, dirPath: string): CheckResult
}
/** Runs after SKILL.md is read — validates file content. */
interface ContentCheck {
description: string
run(ctx: SkillContext): CheckResult
}
/**
* Structure checks run on every entry in `skills/` before SKILL.md is read.
* A fatal error aborts content checks for that entry.
*/
const STRUCTURE_CHECKS: StructureCheck[] = [
{
description: "Entry must be a directory (no loose files in skills/)",
run(dirName, dirPath) {
if (!fs.statSync(dirPath).isDirectory()) {
return { errors: [`Loose file in skills/: ${dirName} (expected only directories)`], fatal: true }
}
return { errors: [] }
},
},
{
description: "Skill directory must contain SKILL.md",
run(dirName, dirPath) {
if (!fs.existsSync(path.join(dirPath, "SKILL.md"))) {
return { errors: [`Missing SKILL.md in skills/${dirName}/`], fatal: true }
}
return { errors: [] }
},
},
{
description: "Name must be kebab-case (lowercase letters, digits, and hyphens only)",
run(dirName) {
if (!/^[a-z0-9]+(-[a-z0-9]+)*$/.test(dirName)) {
return { errors: [`skills/${dirName}: name must be kebab-case (only lowercase letters, digits, and hyphens)`] }
}
return { errors: [] }
},
},
{
description: "Name must be at most 64 characters",
run(dirName) {
if (dirName.length > 64) {
return { errors: [`skills/${dirName}: name is ${dirName.length} characters (maximum 64)`] }
}
return { errors: [] }
},
},
{
description: "Name should use gerund form — first word should end in -ing (e.g. generating-apex-tests)",
run(dirName) {
if (!dirName.split("-")[0].endsWith("ing")) {
return {
errors: [`skills/${dirName}: name should use gerund form (e.g. generating-apex-tests, refactoring-triggers)`],
severity: "warning",
}
}
return { errors: [] }
},
},
{
description: "Skills must be exactly one level deep (no nested category directories)",
run(dirName, dirPath) {
const errors: string[] = []
for (const sub of fs.readdirSync(dirPath)) {
const subPath = path.join(dirPath, sub)
if (fs.statSync(subPath).isDirectory() && fs.existsSync(path.join(subPath, "SKILL.md"))) {
errors.push(
`Nested skill detected: skills/${dirName}/${sub}/SKILL.md — skill directories must be exactly one level deep under skills/`
)
}
}
return { errors }
},
},
]
/**
* Content checks run only on entries that have a valid SKILL.md.
* A fatal error aborts remaining content checks for that entry.
*/
const CONTENT_CHECKS: ContentCheck[] = [
{
description: "SKILL.md must have a valid YAML frontmatter block (--- ... ---)",
run({ dirName, frontmatter }) {
if (!frontmatter) {
return {
errors: [`skills/${dirName}/SKILL.md: missing or malformed YAML frontmatter (expected --- ... --- block at top)`],
fatal: true,
}
}
return { errors: [] }
},
},
{
description:
"Frontmatter must parse as JSON-compatible YAML (js-yaml JSON_SCHEMA); unquoted colons in values break strict parsers",
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
try {
yaml.load(rawFrontmatter, { schema: yaml.JSON_SCHEMA })
} catch (e) {
if (e instanceof yaml.YAMLException) {
const detail = formatYamlFrontmatterParseError(e)
return {
errors: [
`skills/${dirName}/SKILL.md: frontmatter is not valid YAML.
${detail}
Wrap values that contain \`: \` (colon + space), such as long descriptions with parenthetical hints, in single or double quotes.`,
],
}
}
throw e
}
return { errors: [] }
},
},
{
description: 'Frontmatter "name" must be present and match the directory name',
run({ dirName, frontmatter }) {
if (!frontmatter) return { errors: [] }
if (!frontmatter.name) {
return { errors: [`skills/${dirName}/SKILL.md: missing "name" field in frontmatter`] }
}
if (frontmatter.name !== dirName) {
return {
errors: [
`skills/${dirName}/SKILL.md: "name" value ("${frontmatter.name}") does not match directory name ("${dirName}")`,
],
}
}
return { errors: [] }
},
},
{
description: 'Frontmatter "description" must be present and non-empty',
run({ dirName, frontmatter }) {
if (!frontmatter) return { errors: [] }
if (!frontmatter.description?.trim()) {
return { errors: [`skills/${dirName}/SKILL.md: missing or empty "description" field in frontmatter`] }
}
return { errors: [] }
},
},
{
description: 'Frontmatter "description" value must be wrapped in double quotes',
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
const descLine = rawFrontmatter.split(/\r?\n/).find((l) => l.startsWith("description:"))
if (!descLine) return { errors: [] }
const rawValue = descLine.slice(descLine.indexOf(":") + 1).trim()
if (!rawValue.startsWith('"') || !rawValue.endsWith('"')) {
return {
errors: [
`skills/${dirName}/SKILL.md: description value must be wrapped in double quotes — got: ${rawValue.slice(0, 60)}${rawValue.length > 60 ? "…" : ""}`,
],
}
}
return { errors: [] }
},
},
{
description:
'Special characters in description must be escaped (\\\\ and \\")',
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
const descLine = rawFrontmatter.split(/\r?\n/).find((l) => l.startsWith("description:"))
if (!descLine) return { errors: [] }
const rawValue = descLine.slice(descLine.indexOf(":") + 1).trim()
if (!rawValue.startsWith('"') || !rawValue.endsWith('"')) return { errors: [] }
const inner = rawValue.slice(1, -1)
const issues: string[] = []
// Strip valid escape sequences (\\, \") then check for remaining backslashes or unescaped quotes
const stripped = inner.replace(/\\\\|\\"/g, "")
if (stripped.includes('"')) {
issues.push('unescaped " (use \\")')
}
if (stripped.includes("\\")) {
issues.push("unescaped \\ (use \\\\)")
}
if (issues.length > 0) {
return {
errors: [
`skills/${dirName}/SKILL.md: description contains ${issues.join(", ")}`,
],
}
}
return { errors: [] }
},
},
{
description: "SKILL.md must have a non-empty body (instructions after the frontmatter block)",
run({ dirName, body }) {
if (!body.trim()) {
return { errors: [`skills/${dirName}/SKILL.md: body (instructions after frontmatter) is empty`] }
}
return { errors: [] }
},
},
{
description: "Description must be at least 20 words to be information-rich",
run({ dirName, frontmatter }) {
if (!frontmatter) return { errors: [] }
const words = frontmatter.description?.trim().split(/\s+/) ?? []
if (words.length < 20) {
return {
errors: [`skills/${dirName}/SKILL.md: description too short (${words.length} word(s), minimum 20)`],
}
}
return { errors: [] }
},
},
{
description: "Description must be at most 1024 characters",
run({ dirName, frontmatter }) {
if (!frontmatter) return { errors: [] }
const len = frontmatter.description?.length ?? 0
if (len > 1024) {
return { errors: [`skills/${dirName}/SKILL.md: description is ${len} characters (maximum 1024)`] }
}
return { errors: [] }
},
},
{
description: 'Description must include trigger/activation language (contain "use")',
run({ dirName, frontmatter }) {
if (!frontmatter) return { errors: [] }
if (!frontmatter.description?.toLowerCase().includes("use")) {
return {
errors: [
`skills/${dirName}/SKILL.md: description must include trigger context (e.g. "Use this skill when...")`,
],
}
}
return { errors: [] }
},
},
{
description: "Metadata field must be a key-value map (not scalar or array)",
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
const meta = parseMetadataBlock(rawFrontmatter)
if (meta === null) return { errors: [] }
if (meta === "scalar") {
return {
errors: [
`skills/${dirName}/SKILL.md: "metadata" must be a key-value map, not an inline scalar — use indented sub-keys (e.g. metadata:\\n version: "1.0")`,
],
}
}
if (meta === "list") {
return {
errors: [
`skills/${dirName}/SKILL.md: "metadata" must be a key-value map, not a YAML list — use indented key-value pairs instead of "- " list items`,
],
}
}
return { errors: [] }
},
},
{
description: 'Frontmatter must include a metadata block with a "version" field',
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
const meta = parseMetadataBlock(rawFrontmatter)
// Fail if no metadata block exists
if (meta === null) {
return {
errors: [
`skills/${dirName}/SKILL.md: frontmatter must include a "metadata:" block with a "version" field (e.g. metadata:\\n version: "1.0")`,
],
}
}
// Fail if metadata is a scalar (inline value)
if (typeof meta === "string") {
return {
errors: [
`skills/${dirName}/SKILL.md: metadata must be a key-value block, not an inline scalar — use indented sub-keys (e.g. metadata:\\n version: "1.0")`,
],
}
}
// Fail if version is missing inside metadata
if (!meta.version) {
return {
errors: [
`skills/${dirName}/SKILL.md: metadata is missing required "version" field (e.g. version: "1.0")`,
],
}
}
return { errors: [] }
},
},
{
description: 'Version must follow x.y format (e.g. "1.0", "2.5")',
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
const meta = parseMetadataBlock(rawFrontmatter)
if (meta === null || typeof meta === "string") return { errors: [] }
if (!meta.version) return { errors: [] }
const versionPattern = /^\d+\.\d+$/
if (!versionPattern.test(meta.version)) {
return {
errors: [
`skills/${dirName}/SKILL.md: version must follow x.y format (e.g. "1.0", "2.5") — got: "${meta.version}"`,
],
}
}
return { errors: [] }
},
},
{
description: "Compatibility field (if present) must be at most 500 characters",
run({ dirName, frontmatter }) {
if (!frontmatter) return { errors: [] }
if (!("compatibility" in frontmatter)) return { errors: [] }
const len = frontmatter.compatibility?.length ?? 0
if (len > 500) {
return {
errors: [`skills/${dirName}/SKILL.md: compatibility is ${len} characters (maximum 500)`],
}
}
return { errors: [] }
},
},
{
description: "Allowed-tools field (if present) must be a string (not array or object)",
run({ dirName, rawFrontmatter }) {
if (rawFrontmatter === null) return { errors: [] }
const line = rawFrontmatter.split(/\r?\n/).find((l) => l.startsWith("allowed-tools:"))
if (!line) return { errors: [] }
const rawValue = line.slice(line.indexOf(":") + 1).trim()
if (rawValue.startsWith("[") || rawValue.startsWith("{")) {
return {
errors: [
`skills/${dirName}/SKILL.md: "allowed-tools" must be a plain string (space-separated tool names), not a YAML array or object — got: ${rawValue.slice(0, 60)}`,
],
}
}
const nextLineIdx = rawFrontmatter.split(/\r?\n/).indexOf(line) + 1
const lines = rawFrontmatter.split(/\r?\n/)
if (nextLineIdx < lines.length) {
const nextLine = lines[nextLineIdx]
if (nextLine.match(/^\s+- /)) {
return {
errors: [
`skills/${dirName}/SKILL.md: "allowed-tools" must be a plain string, not a YAML list — use space-separated tool names (e.g. "Bash Read Write")`,
],
}
}
}
return { errors: [] }
},
},
{
description: "Skill body should be under 500 lines for context efficiency",
run({ dirName, body }) {
const lines = body.split("\n").length
if (lines > 500) {
return {
errors: [`skills/${dirName}/SKILL.md: body is ${lines} lines (recommended maximum is 500)`],
severity: "warning",
}
}
return { errors: [] }
},
},
]
/**
* Extracts nested key-value pairs from the `metadata:` block in raw frontmatter.
* Returns `null` if no metadata block, `"scalar"` if metadata has an inline value,
* `"list"` if direct children are YAML list items, or a `Record` of sub-keys.
* Nested lists under sub-keys (e.g. cliTools: [{tool:"sf"}]) are allowed.
*/
function parseMetadataBlock(rawFrontmatter: string): Record<string, string> | "scalar" | "list" | null {
const lines = rawFrontmatter.split(/\r?\n/)
const metaIdx = lines.findIndex((l) => /^metadata\s*:/.test(l))
if (metaIdx === -1) return null
const metaLine = lines[metaIdx]
const inlineValue = metaLine.slice(metaLine.indexOf(":") + 1).trim()
if (inlineValue && !inlineValue.startsWith("#")) return "scalar"
let directIndent: number | null = null
const result: Record<string, string> = {}
for (let i = metaIdx + 1; i < lines.length; i++) {
const line = lines[i]
if (!line.startsWith(" ") && !line.startsWith("\t")) break
const indent = line.length - line.trimStart().length
if (directIndent === null) directIndent = indent
const trimmed = line.trim()
if (indent === directIndent && trimmed.startsWith("- ")) return "list"
if (indent !== directIndent) continue
const colonIdx = trimmed.indexOf(":")
if (colonIdx === -1) continue
const key = trimmed.slice(0, colonIdx).trim()
const raw = trimmed.slice(colonIdx + 1).trim()
result[key] = raw.replace(/^(['"])([\s\S]*)\1$/, "$2")
}
return result
}
/**
* Returns the deduplicated list of top-level skill directory names that have
* changed relative to `base` (e.g. `origin/main`) and still exist on disk.
* Deleted skill directories are intentionally excluded — removing a skill is
* valid and requires no structural validation.
*/
function getChangedSkillDirs(base: string): string[] {
const output = execSync(`git diff --name-only ${base}...HEAD`, { encoding: "utf8" })
return [
...new Set(
output
.split("\n")
.filter((f) => f.startsWith("skills/"))
.map((f) => f.split("/")[1])
.filter(Boolean)
),
].filter((dir) => fs.existsSync(path.join(SKILLS_DIR, dir)))
}
/** Formats js-yaml YAMLException with guarded mark fields and optional snippet. */
function formatYamlFrontmatterParseError(e: yaml.YAMLException): string {
const reason =
typeof e.reason === "string" && e.reason.trim() !== "" ? e.reason : "YAML parse error"
const m = e.mark
if (!m) return reason
const line = typeof m.line === "number" ? m.line + 1 : "?"
const col = typeof m.column === "number" ? m.column + 1 : "?"
const index = typeof m.position === "number" ? m.position + 1 : "?"
const head = `${reason} — line ${line}, column ${col} (1-based), character index ${index} in frontmatter YAML`
const snippet = typeof m.snippet === "string" && m.snippet.trim() !== "" ? m.snippet.trimEnd() : ""
return snippet ? `${head}\n${snippet}` : head
}
/**
* Raw YAML between the opening and closing `---` lines (no delimiters).
* `null` if the block is missing.
*/
function parseFrontmatterBlock(content: string): { raw: string; fullMatchLen: number } | null {
const match = content.match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n?/)
if (!match) return null
return { raw: match[1], fullMatchLen: match[0].length }
}
/**
* Parses a SKILL.md file into its frontmatter fields and body.
* `frontmatter` is `null` if the `--- ... ---` block is missing or malformed.
* Wrapping quotes on frontmatter values are stripped.
*/
function parseSkillMd(content: string): {
rawFrontmatter: string | null
frontmatter: Record<string, string> | null
body: string
} {
const block = parseFrontmatterBlock(content)
if (!block) return { rawFrontmatter: null, frontmatter: null, body: content }
const frontmatter: Record<string, string> = {}
for (const line of block.raw.split(/\r?\n/)) {
const colonIdx = line.indexOf(":")
if (colonIdx === -1) continue
const key = line.slice(0, colonIdx).trim()
const raw = line.slice(colonIdx + 1).trim()
// Strip wrapping single or double quotes to match how consumers read values
frontmatter[key] = raw.replace(/^(['"])([\s\S]*)\1$/, "$2")
}
return {
rawFrontmatter: block.raw,
frontmatter,
body: content.slice(block.fullMatchLen),
}
}
/**
* Runs all structure and content checks for a single skill directory.
* Returns errors (block CI) and warnings (advisory, printed but exit 0) separately.
*/
function validateSkill(dirName: string, dirPath: string): SkillResult {
if (!fs.existsSync(dirPath)) {
return { errors: [`skills/${dirName}: directory not found`], warnings: [] }
}
const errors: string[] = []
const warnings: string[] = []
const collectIssues = (result: CheckResult): boolean => {
if (result.errors.length === 0) return false
if (result.severity === "warning") {
warnings.push(...result.errors)
} else {
errors.push(...result.errors)
}
return result.fatal === true && result.severity !== "warning"
}
for (const check of STRUCTURE_CHECKS) {
if (collectIssues(check.run(dirName, dirPath))) return { errors, warnings }
}
const content = fs.readFileSync(path.join(dirPath, "SKILL.md"), "utf8")
const { rawFrontmatter, frontmatter, body } = parseSkillMd(content)
const ctx: SkillContext = { dirName, dirPath, content, rawFrontmatter, frontmatter, body }
for (const check of CONTENT_CHECKS) {
if (collectIssues(check.run(ctx))) return { errors, warnings }
}
return { errors, warnings }
}
/** CLI entry point. Parses flags, resolves the list of skills to check, and reports results. */
function main(): void {
const { values } = parseArgs({
args: process.argv.slice(2),
options: {
/** Validate only skill dirs touched in this branch vs the given base ref. */
changed: { type: "boolean", default: false },
/** Base ref for --changed (e.g. origin/main). Defaults to origin/HEAD. */
base: { type: "string", default: "origin/HEAD" },
},
})
let entries: string[]
if (values.changed) {
entries = getChangedSkillDirs(values.base!)
if (entries.length === 0) {
console.log("No skill directories changed — nothing to validate.")
return
}
console.log(`Validating ${entries.length} changed skill(s): ${entries.join(", ")}`)
} else {
entries = fs.readdirSync(SKILLS_DIR)
}
const allErrors: string[] = []
const allWarnings: string[] = []
let passed = 0
for (const entry of entries) {
const { errors, warnings } = validateSkill(entry, path.join(SKILLS_DIR, entry))
allErrors.push(...errors)
allWarnings.push(...warnings)
if (errors.length === 0) passed++
}
const hasIssues = allErrors.length > 0 || allWarnings.length > 0
const footer = "Spec: https://agentskills.io/specification · Authoring guide: https://github.com/forcedotcom/sf-skills#readme"
if (allWarnings.length > 0) {
console.warn(`\n${allWarnings.length} warning(s):\n`)
for (const w of allWarnings) {
console.warn(`${w}`)
}
console.warn("")
}
if (allErrors.length > 0) {
console.error(`\nSkill validation failed with ${allErrors.length} error(s):\n`)
for (const err of allErrors) {
console.error(`${err}`)
}
console.error("")
console.error(footer)
console.error("")
process.exit(1)
} else {
console.log(`Skill validation passed: ${passed} of ${entries.length} skill(s) checked.`)
if (hasIssues) console.warn(footer)
}
}
main()