Here's how to set up multiple Jest configs for different test suites.Different needsWe have different kinds of tests that we might put in different test suites. Here are potentially two categories:Unit testsIntegration testsWe want to run them separately, at different times. Let's say that we coloca...

Here's how to load .env file in Jest tests..env FileA test suite that relies on real systems, say external APIs, might require sensitive information like API keys in order to interact with them. But as with the source code, we don't want to commit sensitive information to the test code. So, we'll re...

Getting your code organized is challenging. But when it feels as clean as your room after organizing it Saturday morning, it'll feel worth it, and you can go watch cartoons. A key to clean code is clean dependencies.Modules and dependenciesA module knows stuff and does stuff. Getting the contents of...

Here's how to see all the TODOs introduced in a branch.See TODO contentsTwo steps: Diff your PR branch compared to the master branch and then grep for TODOs. For instance:git diff master..my-branch | rg TODO -// TODO: use formatPrimaryErrorMessage in constructors -// TODO: move errors into own modul...

Here's how to run RabbitMQ in a local dev environment.First, install Docker Desktop.Then start dockersystemctl --user start docker-desktopThen get the RabbitMQ image from Docker Hub:docker pull rabbitmq:3-managementThen create a container:docker run -d --name some-rabbit -e RABBITMQ_DEFAULT_USER=gue...

Here's how to make the elixir formatter not add parens to certain functions.Run formatterCode formatting in Elixir can be accomplished with:mix formatCustomize formatTo control how the formatter works, you can edit a .formatter.exs file. This file usually goes in the root of your project.There aren'...

Here are some ways to find the specs for your system via the Linux terminal.High LevelCheck out all the high-level stuff at once.sudo apt install neofetchAnd then run neofetch and get something like this:❯ neofetch ///////////// jaketrent@pop-os ///////////////////// ---------------- ///////*767////...

Here's how to define a type for a declared function.Declare a functionIt's straightforward to type a function signature -- that is, its parameters and return value. For example, string in, number out:function parseItBoom(input: string): number { return parseInt(input, 10); }Define a function typeBut...

We're often called Software Engineers. But sometimes creating software feels more like artistry than engineering.Forming the MalleableWhen Michaelangelo created his David statue, he revealed the image of David in the stone. From a block of nothing, he chiseled away until he was satisfied that he had...

Here's how to redirect in middleware in Next.js 14.Redirect exampleHere's a simple example of src/middleware.ts that does a redirect:import { NextRequest, NextResponse } from 'next/server' export default function middleware(req: NextRequest) { return requireLogin() ?? NextResponse.next() } function ...

Here's how to encode and decode base64 in Node.js.Encode and decode functionsThis is reliable in Node.js. I've read that you can use atob and btoa now, because they're native in later versions of node. But in my experience, I didn't get them working correctly.function encode(data) { return Buffer.fr...

Here's how to store a JSON secret in Vault and parse it out.JSON SecretsSome secrets have more than a single value. An example would be a service account for Google Cloud. They give you a JSON file with a private key, client email, and other value.The pkey.json looks something like this:{ "type": "s...

Here's how to create a file on Google Drive using Promises in TypeScript.Upload a FileMy goal is to upload a file to Google Drive using the JavaScript lib googleapis. I'm on Next.js 14, in TypeScript.ClientOn the client, we've created a file drop zone. On file drop, we're capturing the file and pass...

Here's how to test localhost on your mobile device via ngrok.ScenarioYou have a website that you've been developing on your desktop, and it looks great. And you've been using the device toolbar in browser devtools to test on mobile-sized screens. But it's just not the same. You want to flick the gla...

Here's how to log to DataDog from Next.js.You could use this approach to do most any JSON logging from Next.js, but some of the tips here are specific to DataDog.Why JSON LogYou want logging on your app for visibility when debugging. You want JSON logging because it provides more structure to your l...

Here's how to block websites by editing your /etc/hosts file./etc/hosts is a file where you can make custom DNS (domain name server) entries. In other words, point this name (domain/url) to this IP address. Without a functioning DNS server, typing a url into a browser address bar won't connect to th...

Here's how to format an NTFS Drive in Linux.Use caseYou have a new HDD or SSD, and you want to be able to share it amongst some Linux, Windows or MacOs hosts.You might choose to format it with the NTFS filesystem. It is probably one of the better options for cross-platform support.To make this happe...

Here's how to play a list of songs with mpv.Make Your PlaylistCreate a file with the path of each track on a separate line. You can create your playlist with cmus.It'll look something like this:/mnt/mynas/music/Whitney Houston - Singles/01 I Wanna Dance With Somebody (Who Loves Me).m4a /mnt/mynas/mu...

Here's how to generate both a TypeScript interface and a validator function with a schema with a tool called ajv.Importance of ValidationTypeScript is going to provide type definitions that allow build-time static analysis of your code. It helps you detect if you've written code-level errors.After y...

It's tricky to make a forgiving validator and a unforgiving type definition with AJV's JTDDataType. Here's a method to the madness.I've previously gone over the happy path to generate typedefs from AJV schemas. Let's build off of that example.Additional PropertiesLet's say that we have person REST e...

Error handling with Result types is an improvement upon error throwing.Failures in the Real WorldWriting code that only considers the happy path is relatively easy. But what happens when things go wrong? How do we react? How do we recover? How do we avoid inconsistent state with reverts or retries? ...

This is a way to use Vault to provide app secrets for local dev.Why Use Vault LocallyYou want to use Vault in your local dev environment for a couple main reasons:You'll have a secure way to share secrets.It'll be easier to keep secrets up to date.It'll make your local env match your production envi...

It's a losing proposition to think one can make the final, best decision for all development going forward.To centralize all dev decisions in time and space is folly. 3 main factors are too variable: devs, time and products.Different DevsThe quip is that if you ask 2 devs a question, you'll get 2 di...

Here's a way to trigger caps lock on or off using a command in the terminal.Why on EarthBecause I have the caps lock key remapped usually. But there's some rando key combination that I hit periodically that turns it back on. Some weird keyboard or OS thing, I'm really not sure. But when it happens, ...

Here's how to connect to the AWS VPN from i3, or other non-desktop Linux environments.The ProblemAWS has a VPN client for connecting to AWS VPNs. And they have a build for Linux. ...Good. But it can only be run from a desktop environment, like Gnome. What's an i3 user to do?One option: Patch a versi...

Don't worry, everyone else is making it up too.Magic or Marketing?When you're younger, you look at some of the feats we've accomplished as a human race, and it sometimes feels fantastic. These people become idols, and their accomplishments become world wonders!Then you get a peek behind the curtain:...

Here's how to get your Authy seeds exported so you can use a new time-based one-time password (TOTP) generator.Props to gboudreau, who has done the heavy lifting, figuring out how this is possible, in his gist. For my own sake, what follows is the subset, slightly-modified instructions that worked f...

Sometimes you need to quickly test your client libraries to make sure that you can connect to Postgres with your tech stack, network and credentials combination.Here are a couple of examples of the simplest connection tests. No previous database migrations are required. The query uses the default po...

I had a long, meandering journey to get Postgres to properly connect. I was using an Elixir client, Postgrex, but this advice will probably apply generally. Here's how to avoid a particular problem in getting your postgres clients to connect with tcp/ip on localhost.Defining TCP/IPBy default, if you...

Narrowing input over time will lead to more efficient decision-making and shipped software.In the BeginningIn the beginning of a project or development of a feature, you want as much input as you can get. You have brainstorming sessions. No ideas are off the table. And everyone who might have an int...