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Set up freeCodeCamp on Windows Subsystem for Linux (WSL)

This guide covers some common steps with the setup of WSL2. Once some of the common issues with WSL2 are addressed, you should be able to follow this local setup guide to work with freeCodeCamp on Windows running a WSL distro like Ubuntu.

Enable WSL

Follow the instructions on the official documentation to install WSL2.

Install Ubuntu

  1. We recommended using Ubuntu-18.04 or above with WSL2.

As of November 2023, Ubuntu and Debian are the only Linux distributions officially supported by Playwright, the end-to-end testing library used by freeCodeCamp.

  1. Update the dependencies for the OS

    Terminal window
    sudo apt update
    sudo apt upgrade -y
    

    # cleanup
    sudo apt autoremove -y

Set up Git

Git comes pre-installed with Ubuntu 18.04, verify your Git version with git --version.

~
❯ git --version
git version 2.25.1

(Optional but recommended) You can now proceed to setting up your ssh keys with GitHub.

Installing a Code Editor

We highly recommend installing Visual Studio Code on Windows 10. It has great support for WSL and automatically installs all the necessary extensions on your WSL distribution.

Essentially, you will edit and store your code on Ubuntu-18.04 with VS Code installed on Windows.

If you use IntelliJ Idea, you may need to update your Node interpreter and npm package manager to what is installed on your WSL distro.

You can check these settings by going to Settings > Languages & Frameworks > Node.js and npm.

Installing Docker Desktop

Docker Desktop for Windows allows you to install and run databases like MongoDB and other services like NGINX and more. This is useful to avoid common pitfalls with installing MongoDB or other services directly on Windows or WSL2.

Follow the instructions on the official documentation and install Docker Desktop for your Windows distribution.

There are some minimum hardware requirements for the best experience.

Configure Docker Desktop for WSL

Once Docker Desktop is installed, follow these instructions and configure it to use the Ubuntu-18.04 installation as a backend.

This makes it so that the containers run on the WSL side instead of running on Windows. You will be able to access the services over http://localhost on both Windows and Ubuntu.

Install MongoDB from Docker Hub

Once you have configured Docker Desktop to work with WSL2, follow these steps to start a MongoDB service:

  1. Launch a new Ubuntu terminal

  2. Pull MongoDB from Docker Hub. Please refer to the Prerequisites table for the current version of MongoDB used by freeCodeCamp. For example, if the version number is 5.0.x, replace <x.y> with 5.0 in the following two code snippets.

    Terminal window
    docker pull mongo:<x.y>

  3. Start the MongoDB service at port 27017, and configure it to run automatically on system restarts

    Terminal window
    docker run -it \
      -v mongodata:/data/db \
      -p 27017:27017 \
      --name mongodb \
      --restart unless-stopped \
      -d mongo:<x.y>

  4. You can now access the service from both Windows or Ubuntu at mongodb://localhost:27017.

Installing Node.js and pnpm

We recommend you install the LTS release for Node.js with a node version manager - nvm.

Once installed use this command to install and use the latest Node.js LTS version:

Terminal window
nvm install --lts

For instructions on installing and using a different version of Node.js, please refer to the nvm docs.

Node.js comes bundled with npm, which you can use to install pnpm:

Terminal window
npm install -g pnpm

Set up freeCodeCamp Locally

Now that you have installed the pre-requisites, follow our local setup guide to clone, install and set up freeCodeCamp locally on your machine.

Optimize Windows and WSL

Adjust processor scheduling for background services

This may reduce incidents of Docker containers crashing due to lack of resources.

Open the System Properties control panel by pressing Win + R and entering sysdm.cpl

Enter sysdm.cpl in the Run dialog (screenshot)
Enter `sysdm.cpl` in the Run dialog

Go to Advanced -> Performance -> Settings…

Performance Settings button under Advanced tab in System Properties (screenshot)
Performance Settings button under Advanced tab in System Properties

Under Advanced -> Processor scheduling, choose “Background services”. Do not close the window. Continue to the next tip.

Background services radio button under Advanced tab in Performance Options (screenshot)
Background services radio button under Advanced tab in Performance Options

Increase the size of Windows paging file for the system drive

Under Advanced -> Virtual memory, click “Change…”

Change virtual memory button under Advanced tab in Performance Options (screenshot)
Change virtual memory button under Advanced tab in Performance Options

Choose “Custom size”. Set the initial size to 1.5x and the maximum size to 3x of your physical memory. Then click “Set”.

Set custom size button in Virtual Memory window (screenshot)
Set custom size button in Virtual Memory window

Increase the size of memory allocated to WSL

Create a .wslconfig file in your %UserProfile% directory (typically C:\Users\<UserName>\.wslconfig). Please read the WSL documentation carefully and replace x with values that suit your own needs:

# Settings apply across all Linux distros running on WSL 2
[wsl2]


# How much memory to assign to the WSL 2 VM. The default value might not be enough
memory=xGB


# How much swap space to add to the WSL 2 VM, default is 25% of available RAM
swap=xGB

Increase Node.js max old space size

This fixes the “JavaScript heap out of memory” error with ESLint. Add the following to your ~/.bashrc or ~/.zshrc:

Terminal window
export NODE_OPTIONS="--max-old-space-size=4096"

Avoid pnpm run test

Instead, use the script appropriate to your PR; either pnpm run test:api, pnpm run test:curriculum, or pnpm run test-client.