{
  "slug": "wrangler-test-harness-accesses-durable-object-storage-b60bb3910b70",
  "title": "wrangler test harness accesses Durable Object storage",
  "tools": [
    "wrangler"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-07-17T09:23:58.000Z",
  "announced_at": "2026-07-17T09:23:58.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "When a Worker test needs to seed or inspect SQLite-backed Durable Object state, use `worker.getDurableObjectStorage()` with the binding or exported class name and an instance name or ID, then run SQL with `storage.exec()`.",
    "examples": [
      "const server = createTestHarness({ workers: [{ configPath: \"./wrangler.json\" }] });\nawait server.listen();\nconst worker = server.getWorker();\nconst storage = await worker.getDurableObjectStorage(\"COUNTER\", { name: \"user-123\" });\nawait worker.fetch(\"/counter/user-123\");\nconst rows = await storage.exec(\"SELECT value FROM counters WHERE id = ?\", \"user-123\");\nexpect(rows).toEqual([{ value: 1 }]);"
    ],
    "gotchas": [
      "Version: 4.112.0",
      "classNameOrBindingName (required): The Durable Object exported class name or namespace binding name.",
      "options (required): Select the Durable Object instance by `name` or `id`.",
      "storage.exec(sql, ...params) (required): Executes SQL inside the target Durable Object and returns all rows; SQL parameters follow the query string.",
      "Prerequisite: The Durable Object must be SQLite-backed; the method returns its storage handle.",
      "Prerequisite: Configure the test harness with a Worker via Wrangler config or inline config, then start it with `server.listen()`.",
      "The storage access shown is for a SQLite-backed Durable Object."
    ]
  },
  "why_it_matters": "Seed or assert SQLite-backed Durable Object storage state in a Worker test using `createTestHarness()`.",
  "sources": [
    "https://github.com/cloudflare/workers-sdk/releases/tag/wrangler%404.112.0",
    "https://developers.cloudflare.com/workers/testing/test-harness/prepare-test-state/",
    "https://github.com/cloudflare/workers-sdk/blob/cb6c3f9a5c6d67804cd0cb447cc0837a9f75848c/packages/wrangler/src/api/test-harness.ts"
  ],
  "rank": 0.95035,
  "judge": {
    "publish": true,
    "judge_model": "codex-cli/gpt-6-luna+typesafe/jev-1.13.0",
    "prompt_version": "extract-v7+enrich-v1+judge-v2x3+jev-publish-v1"
  },
  "review_state": "approved",
  "provenance": {
    "run_id": "backfill-20261007",
    "verdict_id": "backfill-20261007:backfill-20261007-1dbc005aad797438-1:gate",
    "evidence_hash": "1184dc3c21966d736b6fb5f8c1205667cd4167061448e267c70db00bba8d926f"
  },
  "review": {
    "draft_hash": "7ce3534dd787cb1dafddb961492f05f6cfb13c746e05146db823111ba1bc0a7b",
    "reviewer": "publication-gate",
    "reviewed_at": "2026-10-07T00:00:00.000Z",
    "decision": "backfill-20261007:gate",
    "reason": "3 of 3 judge runs approved with p_yes >= 0.9 (mean 0.95 >= 0.9; 2 needed) and Jev gave 0.78 (>= 0.6 needed)."
  }
}