chore: import upstream snapshot with attribution

showcase/scripts/__tests__/validate-pins.shared.ts

@@ -0,0 +1,49 @@
+// Shared helpers for validate-pins.*.test.ts files.
+//
+// These tests were originally a single multi-thousand-line file. They
+// were split per describe-category to keep each file comfortably under
+// vitest's hardcoded 60s birpc `onTaskUpdate` RPC window (upstream
+// vitest #6129 — `DEFAULT_TIMEOUT = 6e4` in the bundled birpc). With
+// `pool: 'forks'` (see showcase/scripts/vitest.config.ts) each file
+// gets its own fresh worker + its own fresh 60s RPC budget.
+//
+// This module hosts the tmpdir / write / withTmp helpers and the
+// FIXTURES_DIR / VALIDATE_PINS_SCRIPT path constants so we don't
+// duplicate them across split files.
+
+import fs from "fs";
+import os from "os";
+import path from "path";
+import { fileURLToPath } from "url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+export const FIXTURES_DIR = path.resolve(__dirname, "fixtures", "pins");
+export const VALIDATE_PINS_SCRIPT = path.resolve(
+  __dirname,
+  "..",
+  "validate-pins.ts",
+);
+
+export function tmpdir(prefix = "validate-pins-"): string {
+  return fs.mkdtempSync(path.join(os.tmpdir(), prefix));
+}
+
+export function write(file: string, body: string): void {
+  fs.mkdirSync(path.dirname(file), { recursive: true });
+  fs.writeFileSync(file, body, "utf-8");
+}
+
+/**
+ * Safe-cleanup helper: call body() but always rm -rf tmp in finally so
+ * an assertion failure doesn't leak temp directories into /tmp.
+ */
+export function withTmp<T>(body: (tmp: string) => T): T {
+  const tmp = tmpdir();
+  try {
+    return body(tmp);
+  } finally {
+    fs.rmSync(tmp, { recursive: true, force: true });
+  }
+}