@mostlyworks/prisma-rewind

Framework-agnostic transaction isolation for PostgreSQL tests using Prisma 8.

npm install --save-dev @mostlyworks/prisma-rewind

Prisma 8 is currently available as a release candidate. Development is pinned to @prisma/[email protected]; the package peer range supports that release candidate and subsequent Prisma 8 releases (>=8.0.0-rc.8 <9).

Usage

import { createTransactionalTestHelper } from '@mostlyworks/prisma-rewind';
import { db } from './prisma/db.js';

const testDb = createTransactionalTestHelper(db);

await testDb.startNewTransaction();
try {
  await testDb.client.orm.public.User.create({ email: '[email protected]' });
  // Run assertions using the same stable testDb.client proxy.
} finally {
  await testDb.rollbackCurrentTransaction();
}

Database operations through client require an active test transaction. Starting a second root transaction on the same helper also fails. Use a separate Prisma client and helper for each concurrently active test transaction.

Application code can call client.transaction() while the root test transaction is active. Successful nested work remains visible to the outer transaction, while a thrown error rolls nested work back to a PostgreSQL savepoint and leaves the outer transaction usable. Nested work is still removed by rollbackCurrentTransaction().

The proxy exposes Prisma's non-query raw, enums, and nativeEnums utilities without requiring a transaction. Client lifecycle methods (connect, close, and async disposal) delegate to the original client when no test transaction exists and fail clearly while one is active. The proxied connect() resolves to undefined instead of exposing Prisma's query-capable runtime. Unknown operations remain transaction-bound so a query-capable API can never silently fall back to the original client. Raw transaction-control statements such as COMMIT, ROLLBACK, and SAVEPOINT are rejected when executed through the proxy because they could escape the helper's root rollback or interfere with nested savepoints.

Development

npm install
npm test
npm run tc
npm run lint

PostgreSQL integration tests run when TEST_DATABASE_URL is set:

TEST_DATABASE_URL=postgresql://localhost/postgres npm test