Replace import from css by content transformed by postcss

Input:

import style1 from './style.css';
import style2 from './style.css'; // options: { tagged: ['css', 'lit-element'] }

Output:

var style1 = '/* style.css content */';
import { css } from 'lit-element';
var style2 = css`
    /* style.css content */
`;

1. npm install --save-dev babel-plugin-postcss
2. Add ['babel-plugin-postcss', { options }] to plugins section of babel config.

Regular expression or function which test importee for being parsed as style file (css).
Type: RegExp | Function
Default: /\.css$/
Example: /\.css$/ only .css imports will be parsed

If value is truthy css content will be processed by postcss, postcss config will be loaded by postcss-load-config.
Type: undefined | boolean
Default: undefined

Wrap css content to tagged template, array of two elements. First is tagged function, second is module where import the tagged function from.
Type: undefined | [string, string]
Default: undefined
Example: ['css', 'lit-element']

Input:

import style3 from './style3.css';

Output:

import { css } from 'lit-element';
var style2 = css`
    /* style3.css content */
`;