🥜 goober, a less than 1KB css-in-js solution.

Motivation

I always wondered, if you can get a working solution for css-in-js with a smaller footprint. I started a project and wanted a to use styled-components. Looking at their sizes, it seems that I would rather not include ~12kB(styled-components) or ~11kB(emotion) just so I can use the styled paradigm. So, I embarked in a mission to create a smaller alternative for these well established apis.

Table of contents

• Usage
• Examples
• SSR
• Benchmarks
  • Browser
  • SSR
• API
  • styled
  • setup
  • css
  • targets
  • extractCss
  • glob
• Integrations
  • Babel Plugin
  • Gatsby
• Features
  • Sharing Style
  • Autoprefixer
• Browser Support
• Contributing

Usage

The API is inspired by emotion, styled function. Meaning, you call it with your tagName and returns a vDOM component for that tag. Note, setup is needed to be run before the styled function is used.

import { h } from 'preact';
import { styled, setup } from 'goober';

// Should be called here, and just once
setup(h);

const Icon = styled('span')`
    display: flex;
    flex: 1;
    color: red;
`;

const Button = styled('button')`
    background: dodgerblue;
    color: white;
    border: ${Math.random()}px solid white;

    &:focus,
    &:hover {
        padding: 1em;
    }

    .otherClass {
        margin: 0;
    }

    ${Icon} {
        color: black;
    }
`;

Examples

• Vanilla
• React
• Preact
• SSR with Preact
• Fre

SSR

You can get the critical CSS for SSR, via extractCss. Take a look at this example: CodeSandbox: SSR with Preact and goober and read the full explanation for extractCSS and targets below.

Benchmarks

You results are included inside the build output as well.

Browser

These are not yet measured. Need some time.

SSR

The benchmark is testing the following scenario:

import styled from 'package';

// Create the dynamic styled component
const Foo = styled('div')((props) => ({
    opacity: props.counter > 0.5 ? 1 : 0,
    '@media (min-width: 1px)': {
        rule: 'all'
    },
    '&:hover': {
        another: 1,
        display: 'space'
    }
}));

// Serialize the component
renderToString(<Foo counter={Math.random()} />);

The results are:

goober x 39,348 ops/sec ±1.67% (87 runs sampled)
styled-components x 21,469 ops/sec ±3.60% (85 runs sampled)
emotion x 46,504 ops/sec ±4.67% (85 runs sampled)

Fastest is: emotion

API

As you can see it supports most of the syntaxes of CSS. If you find any issues, please submit a ticket or even a PR with a fix.

styled(tagName: String | Function, forwardRef?: Function)

• @param {String|Function} tagName The name of the dom element you'd like the styled to be applied to
• @param {Function} forwardRef Forward ref function. Usually React.forwardRef
• @returns {Function} Returns the tag template function.

import { styled } from 'goober';

const Btn = styled('button')`
    border-radius: 4px;
`;

Different ways of customizing the styles

Tagged templates functions

import { styled } from 'goober';

const Btn = styled('button')`
    border-radius: ${(props) => props.size}px;
`;

<Btn size={20} />;

Function that returns a string

import { styled } from 'goober';

const Btn = styled('button')(
    (props) => `
  border-radius: ${props.size}px;
`
);

<Btn size={20} />;

JSON/Object

import { styled } from 'goober';

const Btn = styled('button')((props) => ({
    borderRadius: props.size + 'px'
}));

<Btn size={20} />;

setup(pragma: Function, prefixer?: Function, theme?: Function)

Given the fact that react uses createElement for the transformed elements and preact uses h, setup should be called with the proper pragma function. This was added to reduce the bundled size and being able to bundle esmodule version. At the moment I think it's the best tradeoff we can have.

import React from 'react';
import { setup } from 'goober';

setup(React.createElement);

css(taggedTemplate)

• @returns {String} Returns the className.

To create a className, you need to call css with your style rules in a tagged template.

import { css } from "goober";

const BtnClassName = css`
  border-radius: 4px;
`;

// vanilla JS
const btn = document.querySelector("#btn");
// BtnClassName === 'g016232'
btn.classList.add(BtnClassName);

// JSX
// BtnClassName === 'g016232'
const App => <button className={BtnClassName}>click</button>

Different ways of customizing css

Passing props to css tagged templates

import { css } from 'goober';

// JSX
const CustomButton = (props) => (
    <button
        className={css`
            border-radius: ${props.size}px;
        `}
    >
        click
    </button>
);

Using css with JSON/Object

import { css } from 'goober';
const BtnClassName = props => css({
    background: props.color,
    borderRadius: props.radius + 'px'
});

Notice: using css with object can reduce your bundle size.

We also can declare the styles at the top of the file by wrapping css into a function that we call to get the className.

import { css } from 'goober';

const BtnClassName = (props) => css`
    border-radius: ${props.size}px;
`;

// vanilla JS
// BtnClassName({size:20}) -> g016360
const btn = document.querySelector('#btn');
btn.classList.add(BtnClassName({ size: 20 }));

// JSX
// BtnClassName({size:20}) -> g016360
const App = () => <button className={BtnClassName({ size: 20 })}>click</button>;

targets

By default, goober will append a style tag to the <head> of a document. You might want to target a different node, for instance, when you want to use goober with web components (so you'd want it to append style tags to individual shadowRoots). For this purpose, you can .bind a new target to the styled and css methods:

import * as goober from 'goober';
const target = document.getElementById('target');
const css = goober.css.bind({ target: target });
const styled = goober.styled.bind({ target: target });

If you don't provide a target, goober always defaults to <head> and in environments without a DOM (think certain SSR solutions), it will just use a plain string cache to store generated styles which you can extract with extractCSS(see below).

extractCss(target?)

• @returns {String}

Returns the <style> tag that is rendered in a target and clears the style sheet. Defaults to <head>.

const { extractCss } = require('goober');

// After your app has rendered, just call it:
const styleTag = `<style id="_goober">${extractCss()}</style>`;

// Note: To be able to `hydrate` the styles you should use the proper `id` so `goober` can pick it up and use it as the target from now on

glob

To create a global style, you need to call glob with your global tagged template. Usually here's a good idea to place document wide styles.

import { glob } from 'goober';

glob`
  html,
  body {
    background: light;
  }

  * {
    box-sizing: border-box;
  }
`;

Integrations

Babel plugin

You're in love with the styled.div syntax? Fear no more! We got you covered with a babel plugin that will take your lovely syntax from styled.tag and translate it to goober's styled("tag") call.

npm i --save-dev babel-plugin-transform-goober
# or
yarn add --dev babel-plugin-transform-goober

Visit the package in here for more info (https://github.com/cristianbote/goober/tree/master/packages/babel-plugin-transform-goober)

Gatsby

Want to use goober with Gatsby? We've got you covered! We have our own plugin to deal with styling your Gatsby projects.

npm i --save gatsby-plugin-goober
# or
yarn add gatsby-plugin-goober

Features

• Basic CSS parsing
• Nested rules with pseudo selectors
• Nested styled components
• Extending Styles
• Media queries (@media)
• Keyframes (@keyframes)
• Smart(lazy) client-side hydration
• Styling any component
  • via const Btn = ({className}) => {...}; const TomatoBtn = styled(Btn)`color: tomato;`
• Vanilla(via css function)
• globalStyle(via glob) so one would be able to create global styles
• target/extract from elements other than <head>
• vendor prefixing

Sharing style

There are a couple of ways to effectly share/extend styles across components.

Extending

One can simply extend the desired component that needs to be enrich or overwriten with another set of css rules.

import { styled } from 'goober';

// Let's declare a primitive for our styled component
const Primitive = styled('span')`
    margin: 0;
    padding: 0;
`;

// Later on we could get the primitive shared styles and also add our owns
const Container = styled(Primitive)`
    padding: 1em;
`;

Using as prop

Another helpful way to extend a certain component is with the as property. Given our example above we could modify it like:

import { styled } from 'goober';

// Our primitive element
const Primitive = styled('span')`
    margin: 0;
    padding: 0;
`;

const Container = styled('div')`
    padding: 1em;
`;

// At composition/render time
<Primitive as={'div'} /> // <div class="go01234" />

// Or using the `Container`
<Primitive as={Container} /> // <div class="go01234 go56789" />

Autoprefixer

Autoprefixing is a helpful way to make sure the generated css will work seamlessly on the whole spectrum of browsers. With that in mind, the core goober package can't hold that logic to determine the autoprefixing needs, so we added a new package that you can choose to address them.

npm install goober-autoprefixer
# or
yarn add goober-autoprefixer

After the above package is installed it's time to bootstrap goober with it:

import { setup } from 'goober';
import { prefix } from 'goober-autoprefixer';

// Bootstrap goober
setup(React.createElement, prefix);

And voila! It is done!

Browser support

goober uses microbundle to bundle and transpile it's src into code that browsers can leverage. As you might figure it out, until now, Internet Explorer was the buggiest of them all. goober works on IE9, as we've successfully test it.

IE 9
iOS 9.3
Chrome 42
FF 34
Safari 9

Contributing

Feel free to try it out and checkout the examples. If you wanna fix something feel free to open a issue or a PR.

Backers

Thank you to all our backers! 🙏

Sponsors

Support this project by becoming a sponsor. Your logo will show up here with a link to your website.