javascript - Use CSS Modules in React components with Typescript built by webpack

Question

I want to use the css-loader with the 'modules' option of webpack in a React application written in Typescript. This example was my starting point (they are using Babel, webpack and React).

webpack config

var webpack=require('webpack');
var path=require('path');
var ExtractTextPlugin=require("extract-text-webpack-plugin");

module.exports={
    entry: ['./src/main.tsx'],
    output: {
        path: path.resolve(__dirname, "target"),
        publicPath: "/assets/",
        filename: 'bundle.js'
    },
    debug: true,
    devtool: 'eval-source-map',
    plugins: [
        new webpack.optimize.DedupePlugin(),
        new webpack.optimize.UglifyJsPlugin({minimize: true})
    ],
    resolve: {
        extensions: ['', '.jsx', '.ts', '.js', '.tsx', '.css', '.less']
    },
    module: {
        loaders: [
            {
                test: /.ts$/,
                loader: 'ts-loader'
            },
            {
                test: /.tsx$/,
                loader: 'react-hot!ts-loader'
            }, {
                test: /.jsx$/,
                exclude: /(node_modules|bower_components)/,
                loader: "react-hot!babel-loader"
            },
            {
                test: /.js$/,
                exclude: /(node_modules|bower_components)/,
                loader: "babel-loader"
            }, {
                test: /.css/,
                exclude: /(node_modules|bower_components)/,
                loader: ExtractTextPlugin.extract('style-loader', 'css-loader?modules&importLoaders=1&localIdentName=[name]__[local]___[hash:base64:5]!postcss-loader')
            }
        ]
    },
    plugins: [
        new ExtractTextPlugin("styles.css", {allChunks: true})
    ],
    postcss: function() {
        return [require("postcss-cssnext")()]
    }
}

This is a React component I want to style with an accompanying CSS file:

import React = require('react');
import styles = require('../../../css/tree.css')

class Tree extends React.Component<{}, TreeState> {
...

    render() {
        var components = this.state.components
        return (
            <div>
                <h3 className={styles.h3} >Components</h3>
                <div id="tree" className="list-group">
                    ...
                </div>
            </div>
        )
    }
}

    export = Tree

tree.css

.h3{
    color: red;
}

No matter what I'm doing (tried changing the import syntax, tried declaring the 'require' for ts-loader, described here, I always get:

Uncaught Error: Cannot find module "../../../css/tree.css"

at runtime and

error TS2307: Cannot find module '../../../css/tree.css'.

by the TS compiler. Whats happening? Seems to me that css-loader is not even emitting ICSS? Or is it ts-loader behaving wrong?

Answer 1

import has special meaning to TypeScript. It means that TypeScript will attempt to load and understand the thing being imported. The right way is to define require like you mentioned but then var instead of import:

var styles = require('../../../css/tree.css')`