Category: JavaScript

When AWS Lambda functions fail with exceptions, you can have alarms setup to let you know. The problem is the Alarms don’t tell you what the error is, just that a Lambda crashed a bunch of times in a short time frame. Is it something you should keep an eye on? Did something catastrophic happen? Is it something you can ignore? Who knows 🤷🏻‍♂️.

Enter Lambda error parse from CloudWatch filter pattern subscriptions. In this article, we’ll show 2 languages used to do that in a Functional Programming style. Specifically ReScript and Python. While subjective, we’ll do our best to compare and contrast the different approaches. I don’t specifically recommend either language for the task, I just find it interesting to compare and contrast and hope you do too. I’ll cover each function, what it does, and how it fits into the larger whole.

Code – ReScript & Python on Github

I’ve attempted this, like it, and it seems to work if:

• you use Git.
• fast, then good CICD build
• ability to pair program with colleagues

I had the opportunity to build some components and quickly found many needed a lot of parameters. Below is a strategy on how to make them less verbose, type safe regardless of order, and it won’t cause existing code to break when you add new features.

Primitive Obsession is problem where you have a function with multiple parameters of the same type. This causes a risk that you’ll get them in the wrong order, it causes readability problems, and can cause compiled languages to “compile” but still result in incorrect code when it runs.