initial commit

lib/paths.ts

@@ -0,0 +1,26 @@
+import path from "node:path";
+import { HttpError } from "./errors";
+
+/** The portfolio checkout. In Docker it is bind-mounted at /repo; for local
+ *  `npm run dev` it defaults to the sibling ../portfolio folder. */
+export const REPO_DIR = path.resolve(/*turbopackIgnore: true*/
+  process.env.REPO_DIR ?? path.join(/*turbopackIgnore: true*/ process.cwd(), "..", "portfolio")
+);
+
+/** Repo-relative paths the manager owns. Publishing commits only these. */
+export const POSTS_REL = "data/blog-posts.json";
+export const IMG_REL = "public/img/blog";
+
+export const POSTS_FILE = path.join(REPO_DIR, POSTS_REL);
+export const PUBLIC_DIR = path.join(REPO_DIR, "public");
+export const IMG_ROOT = path.join(REPO_DIR, IMG_REL);
+
+/** path.resolve(root, ...segments), refusing anything that escapes root. */
+export function safeJoin(root: string, ...segments: string[]): string {
+  const resolved = path.resolve(/*turbopackIgnore: true*/ root, ...segments);
+  const rel = path.relative(root, resolved);
+  if (rel.startsWith("..") || path.isAbsolute(rel)) {
+    throw new HttpError(400, "path escapes its root");
+  }
+  return resolved;
+}