Setting Up an Nx Monorepo: A Step-by-Step Guide

In the world of software development, managing multiple projects efficiently is critical to maintaining productivity and code quality. Monorepos, or single repositories that host multiple projects, have become a popular solution for this challenge. Nx, a powerful toolkit by Nrwl, is designed to make managing monorepos easier and more efficient. In this blog post, we'll walk you through the process of setting up an Nx monorepo from scratch.

Why Choose Nx for Your Monorepo?

Nx offers a range of features that make it an ideal choice for managing monorepos:

• Project Graph: Visualize and manage dependencies between projects.
• Code Generation: Quickly scaffold new components, services, and more.
• Task Orchestration: Run tasks in parallel to optimize CI/CD pipelines.
• Integrated Testing: Easily set up and run unit tests, end-to-end tests, and more.
• Advanced Dependency Management: Maintain consistent and conflict-free dependencies across projects.

Prerequisites

Before you begin, make sure you have the following installed on your machine:

• Node.js (version 12 or higher)
• npm or Yarn

Step 1: Install Nx

First, you'll need to install Nx globally on your machine. You can do this using npm or Yarn:

npm install -g nx
# or
yarn global add nx

Step 2: Create a New Nx Workspace

Next, create a new Nx workspace. This will be the root directory where all your projects and libraries will reside:

npx create-nx-workspace@latest my-workspace
cd my-workspace

Follow the prompts to set up your workspace. Nx will ask you to choose a preset configuration. For this guide, we'll choose the React preset, but you can select any other preset that suits your needs (e.g., Angular, Next.js, etc.).

Step 3: Adding Projects

Once your workspace is set up, you can start adding projects. For this example, let's create two React applications:

nx generate @nrwl/react:application app1
nx generate @nrwl/react:application app2

These commands will scaffold two new React applications within your monorepo.

Step 4: Creating and Sharing Libraries

One of the biggest advantages of a monorepo is the ability to share code between projects. Nx makes it easy to create reusable libraries. Let’s create a shared utility library:

nx generate @nrwl/workspace:lib shared-utils

You can now import and use this library in both app1 and app2.

Step 5: Running Tasks

Nx provides powerful task orchestration capabilities. You can run tasks like build, test, and lint across multiple projects. For example, to build both applications simultaneously, use the following command:

nx run-many --target=build --projects=app1,app2

Step 6: Visualizing Dependencies

Nx includes a Project Graph tool that allows you to visualize the dependencies between your projects and libraries. To generate and view the project graph, run:

nx graph

This will open a visual representation of your monorepo’s structure in your browser.

Step 7: Setting Up CI/CD

Efficient CI/CD pipelines are crucial for maintaining code quality and deployment speed. Nx supports various CI/CD platforms like GitHub Actions, CircleCI, and Jenkins. Here’s a basic example of a GitHub Actions workflow for an Nx workspace:

Create a .github/workflows/ci.yml file in your repository with the following content:

name: CI

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        node-version: [14, 16]

    steps:
      - uses: actions/checkout@v2
      - name: Use Node.js ${{ matrix.node-version }}
        uses: actions/setup-node@v2
        with:
          node-version: ${{ matrix.node-version }}
      - run: npm install
      - run: nx run-many --target=build --all
      - run: nx run-many --target=test --all

This workflow will build and test your projects on every push or pull request to the main branch.

Conclusion

Setting up an Nx monorepo can significantly enhance your development workflow, making it easier to manage multiple projects, share code, and maintain consistency. With features like code generation, task orchestration, and advanced dependency management, Nx provides a robust solution for modern software development.

By following this guide, you should now have a basic Nx monorepo setup with multiple applications and shared libraries. From here, you can explore