manipulative

A React devtool for live-updating Emotion styles in the browser. When the styles look good, write them to your source files with one click.

manipulative is currently alpha-quality software. If manipulative is not working for your use case, please file an issue and I'll try my best to help.

Requirements

• You're using @emotion/react with css prop
• You're using React Fast Refresh (included w/ create-react-app 4+)

Installation

npm install --dev manipulative
# or
yarn add --dev manipulative

Usage

Run server

The server writes changes to your source files.

npx manipulative-server

Invoke manipulative

Use one of these two approaches.

• useCssPlaceholder() - quickest but not ideal

If you have a create-react-app, you can use the Babel macro without any setup. Add calls to useCssPlaceholder() on elements you want to style.

import { useCssPlaceholder } from "manipulative/macro";

function MyComponent() {
  return (
    <div css={useCssPlaceholder()}>
      <p css={useCssPlaceholder()}>...</p>
    </div>
  );
}

• css__ prop

This more convenient approach requires a little Babel setup (see below).

// no need to import anything
function MyComponent() {
  return (
    <div css__>
      <p css__>...</p>
    </div>
  );
}

Modify and commit styles

In the browser, you should see the manipulative inspector with an input for each useCssPlaceholder() or css__ prop. Type CSS in the textarea to see styles update live. Click "commit" to write changes back to the source files, replacing useCssPlaceholder() and css__ props.

Be sure to remove any imports from manipulative when building for production!

Recommended Babel setup

If you want to use the more convenient css__ syntax, you'll need to install a Babel plugin that runs before React Fast Refresh.

If you have access to the Webpack config (e.g. you ejected CRA), add manipulative/babel to the list of Babel plugins. This plugin needs to run before react-refresh/babel.

{
  loader: 'babel-loader',
  plugins: [
    'manipulative/babel',
    'react-refresh/babel',
  ],
  ...
}

If you have not ejected CRA, you can still use this plugin with something like react-app-rewired. Here is an example config-overrides.js with react-app-rewired.

const { getBabelLoader } = require("customize-cra");

module.exports = function override(config) {
  getBabelLoader(config).options.plugins.unshift(
    require.resolve("manipulative/babel")
  );
  return config;
};

Known Limitations

• manipulative only supports static styles. It does not handle functions or JS variables.
• css__ cannot be used with css prop on the same element

• css__ is transformed to css={...}. Therefore, one will override the other. There may be support for modifying existing styles in the future.