ci: add pinned source-link checker

package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "docs:dev": "vitepress dev docs",
     "docs:build": "vitepress build docs",
-    "docs:preview": "vitepress preview docs"
+    "docs:preview": "vitepress preview docs",
+    "check:links": "node scripts/check-source-links.mjs"
   },
   "devDependencies": {
     "vitepress": "^1.6.4"

scripts/check-source-links.mjs

@@ -0,0 +1,121 @@
+#!/usr/bin/env node
+// Verify that every pinned GitHub source link in docs/ still resolves.
+//
+// Docs snippets carry a source link pinned to a full commit hash, e.g.
+//   https://github.com/<owner>/<repo>/blob/<hash>/<path>#L20-L31
+// (see CLAUDE.md). This script checks each such link exists via the GitHub
+// contents API with ref=<hash>. It is an HTTP existence check only: it does
+// not compare line ranges or snippet content against the file.
+//
+// Set GITHUB_TOKEN or GH_TOKEN in the environment so private repos resolve
+// and the unauthenticated rate limit (60 req/hour) is lifted.
+
+import { readdir, readFile } from "node:fs/promises";
+import { join, dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const DOCS_DIR = join(dirname(fileURLToPath(import.meta.url)), "..", "docs");
+
+// owner / repo / 7-40 hex hash / path, stopping the path at # (line fragment)
+// or any character that would end the link in markdown/HTML.
+const LINK_RE =
+  /https:\/\/github\.com\/([^/\s)"'<>]+)\/([^/\s)"'<>]+)\/blob\/([0-9a-fA-F]{7,40})\/([^\s)"'<>#]+)/g;
+
+async function collectFiles(dir) {
+  const entries = await readdir(dir, { withFileTypes: true });
+  const files = [];
+  for (const entry of entries) {
+    const full = join(dir, entry.name);
+    if (entry.isDirectory()) {
+      files.push(...(await collectFiles(full)));
+    } else if (entry.isFile()) {
+      files.push(full);
+    }
+  }
+  return files;
+}
+
+// The path in a blob URL is percent-encoded (e.g. %28app%29, %2Bpage.svelte).
+// Decode each segment, then re-encode for the API path so characters like
+// "+" survive as %2B rather than being read as a space.
+function apiPath(rawPath) {
+  return rawPath
+    .split("/")
+    .map((seg) => encodeURIComponent(decodeURIComponent(seg)))
+    .join("/");
+}
+
+async function main() {
+  const files = await collectFiles(DOCS_DIR);
+  const links = new Map(); // url -> {owner, repo, hash, path}
+  for (const file of files) {
+    const text = await readFile(file, "utf8");
+    for (const m of text.matchAll(LINK_RE)) {
+      const [url, owner, repo, hash, path] = m;
+      if (!links.has(url)) links.set(url, { owner, repo, hash, path });
+    }
+  }
+
+  if (links.size === 0) {
+    console.log("No pinned source links found in docs/.");
+    return;
+  }
+
+  const token = process.env.GITHUB_TOKEN || process.env.GH_TOKEN;
+  if (!token) {
+    console.warn(
+      "Warning: no GITHUB_TOKEN/GH_TOKEN set. Private repos will 404 and the " +
+        "unauthenticated rate limit (60 req/hour) may be hit.",
+    );
+  }
+  const headers = {
+    Accept: "application/vnd.github+json",
+    "User-Agent": "postguard-docs-link-checker",
+    "X-GitHub-Api-Version": "2022-11-28",
+  };
+  if (token) headers.Authorization = `Bearer ${token}`;
+
+  console.log(`Checking ${links.size} pinned source link(s)...`);
+
+  const broken = []; // link is gone (404)
+  const unverified = []; // could not confirm (rate limit, auth, network, 5xx)
+
+  for (const [url, { owner, repo, hash, path }] of links) {
+    const api = `https://api.github.com/repos/${owner}/${repo}/contents/${apiPath(path)}?ref=${hash}`;
+    let status;
+    try {
+      const res = await fetch(api, { headers });
+      status = res.status;
+    } catch (err) {
+      unverified.push({ url, reason: `network error: ${err.message}` });
+      continue;
+    }
+    if (status === 200) continue;
+    if (status === 404) {
+      broken.push({ url });
+    } else {
+      unverified.push({ url, reason: `HTTP ${status}` });
+    }
+  }
+
+  if (broken.length > 0) {
+    console.error(`\n${broken.length} broken source link(s) (404):`);
+    for (const { url } of broken) console.error(`  ${url}`);
+  }
+  if (unverified.length > 0) {
+    console.error(`\n${unverified.length} link(s) could not be verified:`);
+    for (const { url, reason } of unverified)
+      console.error(`  ${url} (${reason})`);
+  }
+
+  if (broken.length > 0 || unverified.length > 0) {
+    process.exitCode = 1;
+    return;
+  }
+  console.log("All pinned source links resolve.");
+}
+
+main().catch((err) => {
+  console.error(err);
+  process.exitCode = 1;
+});