Registry / testing / postgres-memory-server

postgres-memory-server

library0.2.2jsnpmunverified

Spin up a real, disposable PostgreSQL or ParadeDB instance programmatically from Node.js (v20+) for testing — no Docker required. Version 0.2.2 uses embedded-postgres to bundle PostgreSQL binaries (~10MB) and auto-downloads pg_search and pgvector extensions from official releases. Unlike ephemeral Docker containers, this library avoids daemon dependency, supports snapshot/restore via template databases, and caches extension binaries in ~/.cache. It is inspired by mongodb-memory-server / redisjson-memory-server but tailored for Postgres extension-heavy workloads. Release cadence is active and frequent as of early 2025. Key differentiators: no system Postgres, no Docker, ParadeDB + pgvector support, zero-copy test isolation, cross-platform binaries (macOS arm64/x64, Linux arm64/x64, Windows x64 with limitations).

testing database

npm install postgres-memory-server

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · POSTGRES-MEMORY-SE

postgres-memory-server

testingjavascriptv0.2.2

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

PostgresMemoryServer

✓ import { PostgresMemoryServer } from 'postgres-memory-server'

✗ const { PostgresMemoryServer } = require('postgres-memory-server')

ESM-only package (Node >=20). Use import syntax; require() will fail with ERR_REQUIRE_ESM.

PostgresMemoryServer.create()

✓ const db = await PostgresMemoryServer.create()

✗ const db = new PostgresMemoryServer()

create() is a static async factory. 'new PostgresMemoryServer()' does not exist and throws TypeError.

Client from 'pg'

✓ import { Client } from 'pg'

✗ import { PostgresMemoryServer } from 'pg'

'pg' is a separate peer dependency. You must import Client from the 'pg' package to connect.

Creates a disposable PostgreSQL instance, connects with pg client, runs a query, and stops the server.

import { PostgresMemoryServer } from 'postgres-memory-server'; import { Client } from 'pg'; async function run() { const db = await PostgresMemoryServer.create(); console.log('URI:', db.getUri()); const client = new Client({ connectionString: db.getUri() }); await client.connect(); const res = await client.query('SELECT version()'); console.log(res.rows[0].version); await client.end(); await db.stop(); } run().catch(console.error);

Debug

Known issues

breakingRequires Node.js >= 20. Older versions (18, 19) are not supported and will throw engine error.

fix

Upgrade Node.js to v20 or later.

affects: >=0.0.0

gotchaParallel instances may conflict on port if you don't pass explicit ports. Default port is dynamic but sharing a port across instances causes EADDRINUSE.

fix

Use getPort() or pass a unique port in options: PostgresMemoryServer.create({ port: 0 }) to auto-assign.

affects: >=0.0.0

gotchaExtension downloads use GitHub releases and Homebrew bottles. Network failures or rate limiting will cause timeout errors during first run.

fix

Check network connectivity. Use a caching proxy or pre-download extensions manually to ~/.cache/postgres-memory-server/.

affects: >=0.0.0

deprecatedNo deprecated APIs known in current version (0.2.2).

fix

N/A

affects: >=0.0.0

Errors

Common errors & fixes

Error [ERR_MODULE_NOT_FOUND]: Cannot find module 'postgres-memory-server'

Package not installed or import path incorrect.

fix

Run 'npm install -D postgres-memory-server' and ensure you use 'import { PostgresMemoryServer } from 'postgres-memory-server''.

TypeError: PostgresMemoryServer is not a constructor

Using 'new PostgresMemoryServer()' instead of static factory.

fix

Use 'PostgresMemoryServer.create()' (async) instead.

Error: listen EADDRINUSE: address already in use :::5432

Default or specified port is already occupied.

fix

Use 'getPort()' to find a free port or pass 'port: 0' to auto-assign.

Error: Cannot read properties of undefined (reading 'rows')

Client not connected or query failed silently.

fix

Ensure 'await client.connect()' before querying; check for connection errors.

Upgrade

Version history

0.2.2latest on npm

Audit

Dependencies

embedded-postgresrequiredProvides bundled PostgreSQL binaries used to start the database process.

pgrequiredNode.js PostgreSQL client used internally for queries and connection management.

Agent activity

14 hits · last 30 days

node

Resources

githubhttps://github.com/amanthegreatone/postgres-memory-server ↗

packagepostgres-memory-server ↗

homepagehttps://github.com/amanthegreatone/postgres-memory-server#readme ↗