knex-transact

transact function that provides a simple mechanism to translate SQL transactions into code

NPM Package

npm install @cdellacqua/knex-transact

How to configure

To use this function you must first assign config.knex to your knex instance. For example:

    import { config } from '@cdellacqua/knex-transact';

    import { knex } from 'knex';
    
    const myKnexInstance = knex({
        // your database configuration
    });

    config.knexInstance = myKnexInstance;

How to use

This package exposes a function called transact. It accepts two arguments: an array of functions (or a single function) that return a Promise, and an optional Transaction.

If a function needs to process data with and without having an already initialized transaction, one can easily end up writing some boilerplate code like this:

    
async function aFunctionThatReceivesAnOptionalTransaction(trx?: Transaction) {
    const db = trx || knex.transaction();
    try {
        const tempResult = await db('table').where('property', 'value').select();
        await someOtherFunction(tempResult, db);

        if (!trx) {
            db.commit();
        }
    } catch (err) {
        if (!trx) {
            db.rollback();
        }

        throw err;
    }
}

This library takes care of that boilerplate, thus reducing noise and allowing to write less and cleaner code:

function aFunctionThatReceivesAnOptionalTransaction(trx?: Transaction) {
    return transact([
        (db) => db('table').where('property', 'value').select(),
        (db, tempResult) => someOtherFunction(tempResult, db),
    ], trx);
}