jfmengels' blog

Written by Jeroen Engels, author of elm-review. If you like what you read, you can follow me on Twitter or sponsor me.

There, fixed the docs for you

Hi all 👋 Today, I’m going to be talking about the new major version (v2) of . It contains new rules that will help you fix mistakes in your…

Package releases (August 2021)

I recently spent some time going through the existing issues and features ideas I had for some of my packages. It’s a lot of individual…

What if ESLint's configuration worked like elm-review?

I have used extensively in the past. As a user, as the “ESLint configurator” for my teams, and as a rule author. Since then, I have had…

Easier automatic fixes in elm-review

Some weeks ago I released version of the . It adds a feature allowing to get a portion of the source code as a string. I’ll explain what it…

Measuring cognitive complexity with elm-review

I just published a new package and rule: , which lets you know about functions that are too complex. Cyclomatic complexity Before…

How disable comments make static analysis tools worse

Seeing disable comments in code has always made me feel uneasy. Whenever I encounter one, a bunch of questions pop into my head. What kind…

Tail-call optimization in Elm

…or if you prefer a clickbaity title: “Tail-call optimization, what it is, why it’s tricky, and why you won’t need to worry about it anymore…

Simplify

Today, I’m releasing a new version (1.1.9) of , and releasing a very exciting new package! Highlights: Unused dependencies get removed…

Global and configuration errors

I just released version of the , and of the CLI. The release of the Elm package contains some missing features that could be considered…

You thought you had no dead code?

Today I’m releasing a big patch release (v1.1.5) for , ’s main package to detect and remove unused code from Elm code. I wrote previously…

Great compiler messages? Great test failure messages!

If you’ve written a little bit of Elm code, I hope you’ve tried out which allows you to write and run tests for your Elm code (if you never…

Safe dead code removal in a pure functional language

A few months ago, a colleague of mine wrote this on Slack: Thanks to elm-review I was able to remove ~7300 lines of code in the front end in…

Test-only values

Opaque types is a great technique in Elm. It prevents misuse of a custom type by restricting the possible operations you can apply to it…

1 year of elm-review. What lies ahead?

elm-review v1 was released on September 29th 2019. Today therefore marks the first anniversary of its release! 🥳🎉 Ambitions I have pretty…

Hacktoberfest 2020

Hacktoberfest will be starting in two days, and it’s a good opportunity to get started in open-source and help out the projects you like or…

2.3.0 - Just try it out

This is going to be another simultaneous release for both the CLI and the Elm package. Both bring what I think are very exciting features…

What has happened since elm-review v2?

I am in the final preparations for a new (and exciting) release of , and I noticed I didn’t communicate all the changes that happened since…

Single out elements using phantom types

Today, I will showcase a technique to single out elements from a type, through the medium of a puzzle (which you can try to solve or ignore…

Safe unsafe operations in Elm

In Elm, we often have modules around a data type which needs a validation when you initially create it. For instance, the package defines a…

elm-review v2!

Today I am very excited to release 2.0.0 and to share its new features! tl;dr: Here is the list of the introduced features: New review…

Announcing elm-review

I am happy to announce the release of and its CLI. What is elm-review? is a tool that analyzes your project’s Elm code, and reports…

The API of a water tap

Let’s say we wanted to represent a water tap. This tap will have two knobs, one to control cold water output and another one for warm water…