Validate that GAP directories only contain allowed files (#35)

Adds a file allowlist check to `validate-structure.js` — GAP directories
may now only contain `*.md` files and `metadata.yml`. Rejects unexpected
files or subdirectories with a message pointing contributors to
@graphql/gaps-editors.

Motivation: prevent files like `.nvmrc` from being merged that could
inadvertently affect developer environments.

Author: magicmark

package-lock.json

@@ -12,11 +12,15 @@
     "suggest:format": "echo \"\nTo resolve this, run: $(tput bold)npm run format$(tput sgr0)\" && exit 1",
     "test:format": "prettier --check . || npm run suggest:format",
     "test:spelling": "cspell \"spec/**/*.md\" README.md LICENSE.md",
-    "test:structure": "find ./gaps -maxdepth 1 -type d -name 'GAP-*' | xargs -I{} ./scripts/validate-structure.js {}",
-    "sync:codeowners": "node scripts/sync-codeowners.js"
+    "test:structure": "node scripts/validate-structure.ts",
+    "sync:codeowners": "node scripts/sync-codeowners.ts"
   },
   "devDependencies": {
     "@mlarah/spec-md": "^3.1.0",
+    "@tsconfig/node-ts": "^23.6.4",
+    "@tsconfig/node24": "^24.0.4",
+    "@types/node": "^24.13.2",
+    "@types/validator": "^13.15.10",
     "ajv": "^8.17.1",
     "cspell": "5.9.1",
     "handlebars": "^4.7.9",
@@ -25,6 +29,7 @@
     "nodemon": "2.0.20",
     "p-limit": "^7.3.0",
     "prettier": "^3.8.1",
+    "typescript": "^6.0.3",
     "validator": "^13.12.0",
     "yaml": "^2.7.0"
   }

package.json

@@ -1,28 +1,33 @@
 #!/usr/bin/env node
 
 import { readdir, readFile, writeFile } from "node:fs/promises";
-import { join, dirname } from "node:path";
-import { fileURLToPath } from "node:url";
+import { join } from "node:path";
 import { parse as parseYaml } from "yaml";
 
-const __dirname = dirname(fileURLToPath(import.meta.url));
-const rootDir = join(__dirname, "..");
+const rootDir = join(import.meta.dirname, "..");
 const gapsDir = join(rootDir, "gaps");
 
 async function getGapDirs() {
   const entries = await readdir(gapsDir, { withFileTypes: true });
-  return entries.filter((d) => d.isDirectory() && /^GAP-[1-9]\d*$/.test(d.name));
+  return entries.filter(
+    (d) => d.isDirectory() && /^GAP-[1-9]\d*$/.test(d.name),
+  );
 }
 
 async function main() {
   const dirs = await getGapDirs();
-  dirs.sort((a, b) => parseInt(a.name.split("-")[1], 10) - parseInt(b.name.split("-")[1], 10));
+  dirs.sort(
+    (a, b) =>
+      parseInt(a.name.split("-")[1], 10) - parseInt(b.name.split("-")[1], 10),
+  );
 
   const lines = await Promise.all(
     dirs.map(async (dir) => {
       const metadataPath = join(gapsDir, dir.name, "metadata.yml");
       const metadata = parseYaml(await readFile(metadataPath, "utf8"));
-      const owners = metadata.authors.map((a) => a.githubUsername.replace(/^@/, ""));
+      const owners = metadata.authors.map((a) =>
+        a.githubUsername.replace(/^@/, ""),
+      );
       const ownerList = owners.map((o) => `@${o}`).join(" ");
       return `/gaps/${dir.name}/ ${ownerList}`;
     }),