@aibulat/indexeddb-impl

IndexedDB, implemented in plain JavaScript, in memory. Import it and code that expects a browser database runs in Node or Bun — no browser, no jsdom, no disk, and a clean database every process.

It is a fork of fake-indexeddb by Jeremy Scheff at v6.2.5, with the API unchanged apart from an added installGlobals(). Apache-2.0, and the only package here that is.

Install

npm install --save-dev @aibulat/indexeddb-impl

Use

import "@aibulat/indexeddb-impl/auto";

const request = indexedDB.open("my-db", 1);

That installs indexedDB and every IDB* constructor onto globalThis. To avoid touching globals, take the pieces directly:

import { indexedDB, IDBKeyRange } from "@aibulat/indexeddb-impl";

Pairing with the wrapper

@aibulat/indexeddb is a promise wrapper over the IndexedDB API; this is an implementation of the API itself. Together they give you a typed, promise-based database in a test process:

import "@aibulat/indexeddb-impl/auto";
import { openDB } from "@aibulat/indexeddb";

const db = await openDB("my-db", 1, {
    upgrade(db) {
        db.createObjectStore("keyval");
    },
});

await db.put("keyval", "hello", "greeting");

installGlobals()

The callable form of /auto, for when a side-effect import will not do:

import { installGlobals } from "@aibulat/indexeddb-impl";

installGlobals();

A side-effect import runs once per module registry. Under a runner that shares one process across test files — bun test does, node --test does not — that means it cannot reinstall after a test has replaced or deleted the globals. installGlobals() can, and it also accepts a target other than globalThis.

Behaviour

Storage	In memory, for the life of the process. Nothing is written to disk and there is nothing to clean up.
Scheduling	Tasks are queued with setImmediate where it exists, because IndexedDB requires a transaction to go inactive when the event loop turns. A microtask would run database operations too early.
Runtimes	Node >= 26 and Bun >= 1.3. Built platform: "neutral", so it also runs in a browser or a worker.
Conformance	1,536 of the W3C web-platform-tests IndexedDB tests pass; 3 are recorded as known failures.

Gotchas

• It is not a browser. Three conformance tests are recorded as known failures — one microtask-between-listeners timing that an event-loop emulation cannot express, one that needs a proxy detector, one that needs a browsing context to tear down. The authoritative list is test/wpt/manifests/ in the repository.
• State persists across tests in one process. Databases live in the module, so under a shared-process runner one test's database is visible to the next. Delete what you create, or use a unique database name per test.
• Import /auto before the code under test. The globals have to exist before anything reads indexedDB, which in an ES module means the import has to come first — imports are hoisted, so ordering within a file is by import position.