wrangler test helpers can disable persistence
Introduced 2026-03-13 · score 0.95
HOW TO USE IT
When tests need clean state on each run, set `persist: false` in `unstable_dev()` options or in the `dev` options passed to `unstable_startWorker()`.
const worker = await unstable_dev("./src/worker.ts", { persist: false });const worker = await unstable_startWorker({ entrypoint: "./src/worker.ts", dev: { persist: false } });WHY THIS HELPS
Run a Worker in tests that need a clean state on every run.
REQUIREMENTS AND LIMITATIONS
- Version: 4.73.0
- unstable_dev(script, options) — `script` (required): Worker script path, relative to the project root.
- unstable_dev options — `persist`: Set to `false` to prevent binding data from being read from or written to the filesystem.
- unstable_startWorker options — `entrypoint` (required): Worker entrypoint path, as shown in the v4.73.0 release example.
- unstable_startWorker options — `dev.persist`: Set to `false` in the `dev` options to disable persistence.
- Docs conflict: Current Wrangler API docs mark both unstable APIs as deprecated and recommend `createTestHarness()`; that is newer-version guidance and does not change the v4.73.0 release-note examples.
FIRST-PARTY EVIDENCE
- https://github.com/cloudflare/workers-sdk/releases/tag/wrangler%404.73.0
- https://github.com/cloudflare/workers-sdk/blob/wrangler@4.73.0/packages/wrangler/src/api/dev.ts
- https://developers.cloudflare.com/workers/wrangler/api/
Check the installed version and the source before using it. Entry JSON