chore: establish learning module baseline

OpenMAIC/lib/courseware-repo/identity.ts

@@ -0,0 +1,36 @@
+import path from 'path';
+
+const COURSEWARE_ID_PATTERN = /^[a-zA-Z0-9_-]+$/;
+
+export function isValidCoursewareId(value: unknown): value is string {
+  return typeof value === 'string' && COURSEWARE_ID_PATTERN.test(value);
+}
+
+export function assertCoursewareId(value: unknown): asserts value is string {
+  if (!isValidCoursewareId(value)) {
+    throw new Error('Invalid coursewareId');
+  }
+}
+
+export function isValidCoursewareVersion(value: unknown): value is number {
+  return typeof value === 'number' && Number.isSafeInteger(value) && value >= 1;
+}
+
+export function assertCoursewareVersion(value: unknown): asserts value is number {
+  if (!isValidCoursewareVersion(value)) {
+    throw new Error('Invalid courseware version');
+  }
+}
+
+/** Resolve exactly one direct child without allowing absolute paths or traversal. */
+export function resolveDirectChildPath(rootDir: string, childName: string): string {
+  if (!childName || path.basename(childName) !== childName) {
+    throw new Error('Invalid courseware storage path');
+  }
+  const root = path.resolve(rootDir);
+  const child = path.resolve(root, childName);
+  if (path.dirname(child) !== root) {
+    throw new Error('Invalid courseware storage path');
+  }
+  return child;
+}