co-pg

library2.0.2jsnpmunverified

A wrapper for node-postgres (pg) that provides promise-based methods (e.g., connectPromise, queryPromise) compatible with the co generator-based control flow library and async/await. Current version 2.0.2, last updated in 2022. It allows using PostgreSQL connections and queries with yield or await instead of callbacks, without altering the original pg API. Supports pg, pg-native, and pg-pure backends. The library is in maintenance mode; newer projects should prefer native async/await with pg directly.

database

npm install co-pg

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · CO-PG

co-pg

databasejavascriptv2.0.2

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.

co-pg

✓ const pg = require('co-pg')(require('pg'));

✗ const pg = require('co-pg');

CommonJS only. The library must be called as a function with the pg module as argument. Not available as ESM import.

Client

✓ const client = new pg.Client(connectionString); yield client.connectPromise();

✗ const { Client } = require('co-pg')(require('pg'));

Access Client via the wrapped pg object, not destructured from the wrapper directly.

queryPromise

✓ yield client.queryPromise('SELECT NOW()');

✗ yield client.query('SELECT NOW()');

query is the original callback-based method; queryPromise returns a promise for use with co or async/await.

Demonstrates connecting to PostgreSQL using co-pg with co, querying, and closing connection.

const co = require('co'); const pg = require('co-pg')(require('pg')); co(function*() { const client = new pg.Client(process.env.DATABASE_URL ?? 'postgres://postgres:1234@localhost/postgres'); yield client.connectPromise(); const result = yield client.queryPromise('SELECT NOW() as now'); console.log(result.rows[0].now); client.end(); }).catch(err => console.error(err));

Debug

Known issues

deprecatedco-pg is not actively maintained; favors callback-based pg patterns converted to promises. For new projects, use pg's built-in async/await support with pg.Pool.

fix

Replace co-pg with native pg promises: const { Pool } = require('pg'); const pool = new Pool(); await pool.query(...);

affects: >=2.0.0

gotchaThe library requires an older version of co (4.x) and may not work with modern async/await without co.

fix

Upgrade to 2.0.0 or later, or use async/await directly with co-pg (though co itself is outdated).

affects: <2.0.0

gotchaco-pg wraps pg, but does not automatically handle connection pooling; you must explicitly call done() after using a pooled client.

fix

Always call the done function returned from connectPromise after finishing with the client.

affects: >=0.0.0

breakingVersion 2.0.0 changed the API to be a function that takes the pg module, instead of direct require. Old code like require('co-pg').Client will break.

fix

Use const pg = require('co-pg')(require('pg')); then access pg.Client.

affects: >=2.0.0

Errors

Common errors & fixes

Error: Cannot find module 'co-pg'

Package not installed or missing from package.json.

fix

Run 'npm install co-pg'

TypeError: require(...) is not a function

Calling require('co-pg') without passing the pg module; in v2, co-pg exports a function that must be called.

fix

Use const pg = require('co-pg')(require('pg'));

TypeError: client.queryPromise is not a function

Client was not created from the wrapped pg object, or the wrapper was not correctly initialized.

fix

Ensure pg = require('co-pg')(require('pg')) and use new pg.Client(...).

Upgrade

Version history

2.0.2latest on npm

Audit

Dependencies

pgrequiredPeer dependency: wraps pg API with promise helpers. Must be provided by user.

Agent activity

11 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/basicdays/co-pg ↗

packageco-pg ↗

homepagehttps://github.com/basicdays/co-pg ↗