Package Exports

babel-plugin-emotion
babel-plugin-emotion/lib/macro
babel-plugin-emotion/lib/macro-styled

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (babel-plugin-emotion) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

babel-plugin-emotion

Babel plugin for the minification and optimization of emotion styles.

The Babel Plugin is highly recommended, but not required in version 8 and above.

Feature table

Feature/Syntax	Native	Babel Plugin Required	Notes
css``	✅
`css(...)`	✅		Generally used for object styles.
styled('div')`` syntax	✅		Both string and object styles work without this plugin.
styled.div`` syntax		✅	Supporting the shortcut syntax without the Babel plugin requires a large list of valid elements to be included in the bundle.
Minification		✅	Any leading/trailing space between properties in your `css` and `styled` blocks is removed. This can reduce the size of your final bundle.
Dead Code Elimination		✅	Uglifyjs will use the injected `/#__PURE__/` flag comments to mark your `css` and `styled` blocks as candidates for dead code elimination.
Static Extraction		✅	Generated CSS that is eligible for extraction can be moved to an external css file.
Source Maps		✅	When enabled, navigate directly to the style declaration in your javascript file.
`css` as Prop		✅	Convenient helper for calling `css` and appending the generated className during compile time.

Example

const myStyles = css`
  font-size: 20px;
  @media(min-width: 420px) {
    color: blue;
    ${css`width: 96px; height: 96px;`};
    line-height: 26px;
  }
  background: green;
  ${{ backgroundColor: "hotpink" }};
`

Out

const myStyles = /* #__PURE__ */css(
  'font-size:20px;@media(min-width:420px){color:blue;',
  /* #__PURE__ */ css('width:96px;height:96px;'),
  ';line-height:26px;}background:green;',
  { backgroundColor: 'hotpink' },
  ';'
)

Installation

npm install --save-dev babel-plugin-emotion

Usage

Via `.babelrc` (Recommended)

.babelrc

Without options:

{
  "plugins": ["emotion"]
}

With options:

Defaults Shown

{
  "plugins": [
    ["emotion", { 
      "hoist": false,
      "sourceMap": false,
      "extractStatic": false,
      "importedNames": {
        "styled": "styled",
        "css": "css",
        "keyframes": "keyframes",
        "injectGlobal": "injectGlobal",
        "fontFace": "fontFace",
        "merge": "merge"
      }
    }]
  ]
}

Recommended Setup

Use Babel's env property

.babelrc

{
  "env": {
    "production": {
      "plugins": [["emotion", { "sourceMap": false, "hoist": true }]]
    },
    "development": {
      "plugins": [["emotion", { "sourceMap": true, "hoist": false  }]]
    }
  }
}

Via CLI

babel --plugins babel-plugin-emotion script.js

Via Node API

require("@babel/core").transform("code", {
  plugins: ["babel-plugin-emotion"]
});

Options

`hoist`

boolean, defaults to false.

This option enables the following:

Any argument supplied to css or styled is hoisted.

By hoisting the argument, or assigning the value to a variable, emotion is able to leverage the use of a WeakMap cache to increase performance. Users of object styles will benefit the most from enabling this option.

css({ color: 'brown' });

Out

var _ref = { color: 'brown' };
css(_ref);

`sourceMap`

boolean, defaults to false.

This option enables the following:

Injected source maps for use in browser dev tools

Documentation

`extractStatic`

boolean, defaults to

This option enables the following:

Extract static styles into CSS files.

Documentation

`importedNames`

object, defaults to

{
  "styled": "styled",
  "css": "css",
  "keyframes": "keyframes",
  "injectGlobal": "injectGlobal",
  "fontFace": "fontFace",
  "merge": "merge"
}

This option enables the following:

Configurable import names

Documentation