claude-code with OpenAI mode fix

tests/mocks/file-system.ts

@@ -0,0 +1,32 @@
+import { mkdtemp, rm, writeFile, mkdir } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+export async function createTempDir(
+  prefix = "claude-test-",
+): Promise<string> {
+  return mkdtemp(join(tmpdir(), prefix));
+}
+
+export async function cleanupTempDir(dir: string): Promise<void> {
+  await rm(dir, { recursive: true, force: true });
+}
+
+export async function writeTempFile(
+  dir: string,
+  name: string,
+  content: string,
+): Promise<string> {
+  const path = join(dir, name);
+  await writeFile(path, content, "utf-8");
+  return path;
+}
+
+export async function createTempSubdir(
+  dir: string,
+  name: string,
+): Promise<string> {
+  const path = join(dir, name);
+  await mkdir(path, { recursive: true });
+  return path;
+}