macaron

comptime-css is now called macaron!

macaron is a zero-runtime and type-safe CSS-in-JS library made with performance in mind

Powered by vanilla-extract
Allows defining styles in the same file as components
Zero runtime builds
Supports both styled-components API and plain styling api that returns classes.
Stitches-like variants
First class typescript support
Out of box support for react and solidjs
Supports esbuild and vite (with hmr)

Example

Styled API

import { styled } from '@macaron-css/solid';

const StyledButton = styled('button', {
  base: {
    borderRadius: 6,
  },
  variants: {
    color: {
      neutral: { background: 'whitesmoke' },
      brand: { background: 'blueviolet' },
      accent: { background: 'slateblue' },
    },
    size: {
      small: { padding: 12 },
      medium: { padding: 16 },
      large: { padding: 24 },
    },
    rounded: {
      true: { borderRadius: 999 },
    },
  },
  compoundVariants: [
    {
      variants: {
        color: 'neutral',
        size: 'large',
      },
      style: {
        background: 'ghostwhite',
      },
    },
  ],

  defaultVariants: {
    color: 'accent',
    size: 'medium',
  },
});

// Use it like a regular solidjs component
function App() {
  return (
    <StyledButton color="accent" size="small" rounded={true}>
      Click me!
    </StyledButton>
  );
}

Styling API

The styling API is the same api is vanilla-extract, but allows styles to be defined in the same file, increasing the authoring experience.

Check out vanilla-extract docs

Limitations

The style declarations should preferably be at the top level and not inside a function.
All the properties passed to them should be evaluatable at build time and should not use any of the browser specific APIs (window, document)
Each style declaration should be it’s own variable declaration

How it works

The esbuild/vite plugin loads every ts and js file and runs @macaron-css/babel plugin on it.

The babel plugin looks for variable declarations in your code and checks if they are of macarons’s API like styled or recipe etc.

It finds the styles defined in the currently processed file, looks for all their referenced identifiers, gets all their declarations and repeats this cycle until no more are found and constructs a new babel program of these statements.

It then converts that AST to string and generates a virtual file from it and returns the contents of this virtual file along with the metadata.

It also generates unique filename for these css files based on murmurhash.

It also adds imports for those extracted styles in the current file.

It tags all these extracted files in a namespace and pre evaluates them at build time using vanilla-extract

For example, the plugin will transpile:

// main.ts
import { styled } from '@macaron-css/solid';

const StyledButton = styled('button', {
  base: {
    borderRadius: 6,
  },
  variants: {
    color: {
      neutral: { background: 'whitesmoke' },
      brand: { background: 'blueviolet' },
      accent: { background: 'slateblue' },
    },
  },
  defaultVariants: {
    color: 'accent',
  },
});

To This:

// main.ts
import { _StyledButton } from 'extracted_1747103777.css.ts';
import { $$styled as _$$styled } from '@macaron-css/solid/runtime';

const StyledButton = _$$styled('button', _StyledButton);

and

// extracted_1747103777.css.ts
import { recipe as _recipe } from '@macaron-css/core';

const _StyledButton = _recipe({
  base: {
    borderRadius: 6,
  },
  variants: {
    color: {
      neutral: { background: 'whitesmoke' },
      brand: { background: 'blueviolet' },
      accent: { background: 'slateblue' },
    },
  },
  defaultVariants: {
    color: 'accent',
  },
});

module.exports = { _StyledButton };

Which gets further compiled to:

// extracted_1747103777.css.ts
import 'extracted_1747103777.vanilla.css';
import { createRuntimeFn } from '@macaron-css/core/create-runtime-fn';

const _StyledButton = createRuntimeFn({
  defaultClassName: 'extracted_1747103777__1g7h5za0',
  variantClassNames: {
    color: {
      neutral: 'extracted_1747103777_color_neutral__1g7h5za1',
      brand: 'extracted_1747103777_color_brand__1g7h5za2',
      accent: 'extracted_1747103777_color_accent__1g7h5za3',
    },
  },
  defaultVariants: {
    color: 'accent',
  },
});

module.exports = { _StyledButton };

The extracted css will look something like this:

/* extracted_1747103777.vanilla.css */
.extracted_1747103777__1g7h5za0 {
  border-radius: 6px;
}
.extracted_1747103777_color_neutral__1g7h5za1 {
  background: whitesmoke;
}
.extracted_1747103777_color_brand__1g7h5za2 {
  background: blueviolet;
}
.extracted_1747103777_color_accent__1g7h5za3 {
  background: slateblue;
}

GitHub

View Github