TLDR

When using database transactions with Strapi, use the query API, NOT the services API.

Explaination

I started using Strapi few month ago to code our backend at Burrowvest.com, a platform we built with my cofounder to buy slices of high yield Real Estate in 3 clics.

Strapi is a headless CMS developed by the eponymous French company that offers an easy-to-use API on top of Koa. It's plugin system makes development fast as it proposes an admin interface out-of-the-box, a customizable file upload system and a straight-forward database configuration (among others). The main drawback to me was the lack of support of typescript since I got used to it for some years now. Static typing systems efficiency to catch bugs before deployment has been proven over the past decades and was essential to me. But I still decided to give Strapi a try to expand my horizon beyond Express, Koa and Nestjs.

I have to say, coming from Nestjs, Strapi is a breath of fresh air. I felt freed from the strong opinionated architecture principles of Nestjs and rediscovered the joy of developing with bare simple JavaScript. With good practices and project configuration, it is possible to write scalable JavaScript application. Strapi is still under intense development and a first typescript support has been announced with version 4.0.2. It sounds promising and I will pay close attention to it.

That being said, with version 3.6.8, I ran into an issue when developing our system at Burrowvest.com. To ensure the integrity of our data, our endpoint to buy slices of Real Estate is implemented using database transactions. If an issue occurs during the sell, the transaction is rolled back and our system stays in a consistent state. Since we use a Postgres database, database transactions are usable. At first we implemented them this way:

The Strapi services API offers a simple way to query the database in a transaction manner.

But during testing, it didn't work as expected. When an issue occured, the database transaction wasn't rolled back. The data stayed in an inconsistent state as if the database transaction wasn't even taken into account. By digging into Strapi's implementation, I found the cause of the issue:

When querying the database with the services API, Strapi calls the query API under the hood but doesn't pass all the parameters down. The database transaction gets lost and the query is actually made instead of awaiting to be committed. So I used the query API directly instead:

And it worked as expected. The fire was extinguished, at least for now.

Strapi lets developers query the database using the query and services APIs, but the services API is incomplete. That is misleading and error prone, and it won't be long since a developer introduces the bug again. I want developers to be enforced to use the query API when they need to query the database. Since I can't rely on typescript, I will explain in another blogpost how I made use of the eslint rule no-restricted-syntax to tackle the issue once for all.