react-router 4 doesn't display components - reactjs

Question

i'm having 2 routes in my react-redux app:
ReactDOM.render(
<Provider store={store}>
<BrowserRouter>
<div>
<Route path = '/a' component = {ContainerComponent} />
<Route path = '/b' component = {ContainerComponent} />
</div>
</BrowserRouter>
</Provider>,
document.getElementById('app'));
On http://localhost:8080/a i can see my ContainerComponent.
On http://localhost:8080/b i can also see my ContainerComponent.
But on http://localhost:8080/a/b i'm getting 404-error, although i expect to see two ContainerComponents at the same time, like i saw in many tutorials!
My webpack config:
var HTMLWebpackPlugin = require('html-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
var HTMLWebpackPluginConfig = new HTMLWebpackPlugin({
template: __dirname + '/app/index.html',
filename: 'index.html',
inject: 'body'
});
module.exports = {
entry: __dirname + '/app/index.js',
module: {
loaders: [
{
test: /\.js$/,
exclude: /node_modules/,
loader: 'babel-loader'
}, {
test: /\.css$/,
use: ExtractTextPlugin.extract({
fallback: 'style-loader',
use: 'css-loader?modules,localIdentName="[name]-[local]-[hash:base64:6]"'
})
}]
},
output: {
filename: 'transformed.js',
path: __dirname + '/build'
},
devServer: {
historyApiFallback: true
},
plugins: [
HTMLWebpackPluginConfig,
new ExtractTextPlugin('styles.css')
]
};

Answer 1

ReactDOM.render(
<Provider store={store}>
<BrowserRouter>
<div>
<Route path = '/a' component = {ContainerComponent} />
<Route path = '/b' component = {ContainerComponent} />
<Route path = '/a/b' component = {ContainerComponent} />
</div>
</BrowserRouter>
</Provider>,
document.getElementById('app'));
You need to define the third route also. Because of the functioning of the path matching, while not using the exact param, the BrowserRouter will match as many routes as defined whose path matches the URL browsed. In this case, with URL /a, you will get two components rendered. But if you browse URL /a/b, the only route that will match the path is the third one. Because you hadn't defined in your code you get a proper 404 error.

Answer 2

Ok, finally, solved the problem by modifying webpack.config.js. Replaced this:
output: {
filename: 'transformed.js',
path: __dirname + '/build',
},
with this:
output: {
filename: 'transformed.js',
path: __dirname + '/build',
publicPath: '/'
},