Testing in ReScript

• rescript-schema

  2 117 8.5 ReScript

  The fastest composable parser/serializer for ReScript (and TypeScript)

Hello, I’m Dmitry Zakharov, a Frontend-engineer at Carla and author of rescript-struct. After using ReScript for two years, of which 9 months are in production, I’ve gotten some insights about testing I wanted to share. I use ReScript not only for FE but for different areas, so if you’re a BE engineer or create a CLI tool, this article will also be useful for you.

• rescript-ava

  1 8 1.9 ReScript

  ReScript bindings for Ava

Regarding unit testing, the library you use doesn't really matter. Choose any that works for you. My personal preference is to use bindings for AVA.

• InfluxDB

  www.influxdata.com featured

  Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.

  

• rescript-jest

  2 292 5.4 ReScript

  ReScript bindings for Jest

Another popular option is to use bindings for Jest. However, in my opinion, Jest is a monstrous combine that is slow, has a hacky mock system, bad ESM support, and purely tries to mimic DOM API with JSDOM. AVA literally doesn't have any of these. Also, the available Jest bindings don't allow doing multiple assertions per test, which is often useful to me.

• rescript-test

  3 77 6.0 ReScript

  A lightweight test framework for ReScript

Besides bindings for JavaScript libraries, there is rescript-test - a lightweight test framework written in ReScript for ReScript. I have heard that some people like it, but for me, it lacks coverage output and Wallaby support.

• execa

  20 6,396 9.6 JavaScript

  Process execution for humans

For FE, it’s usually Cypress or Playwright; for BE, it’s to run a server and start sending requests; for CLI, I like the tool called execa.

• rescript-stdlib-vendorer

  2 11 5.5 ReScript

  Tool to support usage of a vendored standard library in ReScript

One problem is that it suggests creating A.res, which is publicly available from other application parts. It’s usually fine for FE apps, but for developing BE and CLIs, I prefer to follow the hexagonal architecture by creating the implementation inside the Main.res and passing it to other modules via function arguments. Once again, an example from rescript-stdlib-vendorer:

• Playwright

  382 61,953 9.9 TypeScript

  Playwright is a framework for Web Testing and Automation. It allows testing Chromium, Firefox and WebKit with a single API.

  

For FE, it’s usually Cypress or Playwright; for BE, it’s to run a server and start sending requests; for CLI, I like the tool called execa.

• SaaSHub

  www.saashub.com featured

  SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives

  

• ESLint

  382 24,341 9.7 JavaScript

  Find and fix problems in your JavaScript code.

  

If you are afraid of test code leaking into the application. You can use eslint to prevent this:

Suggest a related project