A component library is one of the coolest things a web developer can make, but if you don't know how to make one, let me guide you a bit.
Before we begin I would like to tell you, that I am not a pro at making component libraries, it's just from my experience developing a component library before.
Prerequisites
Before you get started, these are the following you should know:
Basics of React
Typescript (Optional but preferred, you can use Javascript too)
Why make a component library?
A react component library can be useful in many ways, you can use it in your projects as you scale and want uniformity or you can make your library open-source for everyone to use and contribute.
Tools Required
React - since, this is a tutorial about a react component library
Typescript - this is optional but recommended
Storybook - it's fine if you haven't heard of it, don't freak out. We will be using this to preview our components
Getting Started
There are a lot of ways we can set up our library, if you want to make several packages in the same organization I would recommend using a monorepo but for the sake of this tutorial we will be setting up a very simple library from scratch.
So, first of all, go ahead and make a package.json file:
npm init
Once, you have initialized the project, we will start installing our dependencies. Unlike, in a normal project where you would just install the dependencies directly with npm i [dep-name]
, here we will be using dev-dependencies and peer-dependencies.
Dev-dependencies are the dependencies that do not get packaged in the bundle and do not contribute to the size of our library, it is a dependency that you only require during development.
Peer dependencies basically tell you that you need to have a certain package installed to use the library, for example, if I have a library named avi-lib
and it has peer dependencies as react
& react-dom
, then if I want to use avi-lib
in my project I need to have react
& react-dom
already installed as dependencies in the project.
Now go ahead and install react
, react-dom
, tyepscript
, & @types/react
, @types/react-dom
as devDependencies.
yarn i -D react react-dom typescript @types/react @types/react-dom
Add react
& react-dom
as peer-dependencies with appropriate versions:
{
...
peerDependencies: {
"react": ">=16.0.0",
"react-dom": ">=16.0.0"
}
...
}
Next, initialize a tsconfig file:
npx tsc --init
In the tsconfig.json
file, go ahead and enable jsx
with "jsx": "react"
option.
Making the Component
Once this is done make a directory src
or whatever you wish to name it. This directory will contain all code.
Inside src
, make another directory components
and create a file Button.tsx
. Now, open the file and write out a simple button:
import React from 'react';
export interface ButtonProps {
children: React.ReactNode;
onClick: () => void;
}
export const Button = ({ children, onClick }: ButtonProps) => {
return <button onClick={onClick}>{children}</button>;
};
Now inside the src
directory, create a index.ts
file, and write out the following:
export { Button, ButtonProps } from "./components/Button"
Storybook
Storybook is an amazing tool that is almost essential for component libraries, it helps you out with previewing your components adding documentation for them, and even lets you host the components for others to test. For the sake of this article, we will be primarily using it for testing our components.
To setup storybook in your library, run the following:
npx storybook --init
Storybook automatically detects that this is a react library and installs it accordingly. After it has done installing you will see a .storybook
directory and a src/stories
directory. You don't really have to do anything with the .storybook
directory, you will use your components in the src/stories
directory.
Inside the src/stories
directory you will see a bunch of stuff, but don't worry about it, it is all just mock data. You can go ahead and empty it leaving only the Button.stories.tsx
. Now you will see a lot of things in this file go ahead and empty it and type in the following:
import React, { useState } from 'react';
import { storiesOf } from '@storybook/react';
import { Button } from '../';
const stories = storiesOf('Button', module);
stories.add('Button', () => {
const [value, setValue] = useState('Hello');
const setChange = () => {
setValue(value === 'Hello' ? 'Bye' : 'Hello');
};
return <Button onClick={setChange}>{value}</Button>;
});
Now go ahead and check it out, run the following in your terminal:
npm run storybook
This will open a browser window on localhost:6006
, and you can see our little button working, its value
changes on being clicked.
That's about it, now go ahead and add your own magic to the button, make more components, and similarly, you can even create hooks.
Documentation
It is a good idea to document things about your components in your library in a README file or on a docs website, it helps out anyone using your library. For the sake of this tutorial, we will not be writing documentation because it only contains a single button component.
Bundling
Once you are done with making your components, let's bundle our library.
It's a good idea to bundle because it helps you produce a single file. Some people prefer dragging and dropping a single file in their projects. A single file can also be used for CDNs.
To bundle your component you will have to use a bundler. There are a lot of options out there but here we will be using tsup because tsup doesn't require a configuration for our use case.
To install tsup, do the following:
yarn add -D tsup
This installs tsup as a dev-dependency, now inside your package.json
file add a script:
{
...
scripts: {
...
"build": "tsup src/index.ts --dts"
}
...
}
Now, go ahead and run yarn build
, this will create a index.js
file inside the dist
directory. If you observe, we added a --dts
in our build script, this will generate the type definitions for our project in index.d.ts
.
Publishing
Now that all is done, it's time to show what you have built to the world (or not if it's for personal use). Before publishing, go to your package.json
and you will find a few things, choose a name for your library and add an appropriate version (you can use semantic versioning if you don't know how to), a description of what it does, and a few keywords to make your library discoverable.
Now add a .npmignore
file, this is very similar to .gitignore
, this file will contain what you don't want to publish along with your library, for example, node_modules
. Though this file is optional even if you don't include it, the .gitignore
file will be used instead.
If you are not logged in to your npm account do npm login
and you will have to enter your username and password. In the case, you don't have an npm account you can go to https://www.npmjs.com/ and register for one.
Once you have done that just simply run this command in the terminal:
npm publish
Once it finishes without any errors, Congrats! Your library has been published. Now you (and others too) can use your library in your projects.
Tips
Try to use typescript
Add documentation in your README & if you want, a docs website
I have not done it in the article but use git and make changes on a different branch than
main
Read more on Storybook, its templates, and documentation
More Resources
Hope you enjoyed the read and learned something from it. In the case, you want to add something or find a mistake and wish to point it out, please feel free to do so in the comments.
Top comments (29)
Do be careful when creating a component library that is going to be used within a company. Some general tips: Make sure you follow React design patterns like composition and read up on the open/closed principle, otherwise you're going to create a lot of frustration for your fellow dev. If you're extending an existing UI component library, make sure you follow the same pattern and dont create black boxes for the components that you're extending.
Thanks for adding that!
Hi, at the time of posting this comment,
npx storybook --init
doesn't work and based on the documentation, it's because a project creation framework wasn't used. So simply usingnpx sb init
worked fine.Thanks for pointing that out!
Hey, thanks for putting this article together, I'm just looking into this now. I'm using CSS modules. It would've been good to have seen use of tsup with some css support as that appears to be one of its limiting factors and the documentation is a little thin around that area. Have you tried it in this context?
I haven't tried using CSS modules with tsup so I don't have much knowledge on that, however you can try using rollup, it has a wide range of plugins and more configurable, you will just have to spend a little more time on its config than tsup. You can look at one of my old projects: github.com/AviAvinav/aloria-ui, I have used CSS modules with rollup here, you should look into the docs if anything's changed, since the project is old.
Why do you strongly recommend typescript over JavaScript ?
Specifically for a component library, I would recommend using typescript because it provides sort of a built-in documentation.
Let's say the
Button
component that we used in the article also had asize
prop which is only supposed to accept values:lg
,md
, orsm
(standing for large, medium and small respectively), then I can just define my component's props like this:This way when the user actually uses our component inside their project if they put any other value for the
size
prop besideslg
,md
, orsm
, they will recieve a warning. If you would notice, I also added a comment above thesize
prop, this helps as sort of a documentation. You can see this happening in the image below:As you can see, my editor shows me there's a problem because
large
is not an acceptable value for thesize
prop. Also you can see when I hover over thesize
prop it shows me the acceptable values and the comment we wrote before.This also provides better intellisense as you can see in the image below:
By default all the props you give to your components (in typescript) will be complusory, to make them optional you can just add a
?
, like this:This makes the
onClick
prop optional so now it won't cause an error ifonClick
is not specified during usage, but if you don't specify thesize
prop or addchildren
during usage it will show a warning as they are compulsory (do not have a?
).An alternative to TypeScript is PropTypes npmjs.com/package/prop-types
I have heard of it but haven't tried it
thanks, it helps me a lot. Can I translate it into Chinese and share it to more people on juejin.im ?
Sure, go ahead, just mention the original article too. Let me know once you have done it. Thanks!
juejin.cn/post/7145001624288067615
Awesome! Thanks!
Hey, there's a typo in your article title. It should be 'Library' but you've written 'Librabry'
Thanks for pointing that out, I was so focused on looking at the body of the post that I forgot to check the typo in the title.
check out this - TSDX - Zero-config CLI for TypeScript package development tsdx.io/
I did know about it and have tried it in the past but from what I know it's no longer being maintained, so I wouldn't recommend using it.
oh..okay. make sense.
That was a nice read! Liked, bookmarked and followed, keep the good work! 🙌
Thanks!
This is good.
Thanks!
Nice article. I wrote a similar article recently
Btw, nx is also an option for managing monorepos
Haven't tried nx before, but will try it out