Structuring React and Redux Applications

There’s no idiomatic way to structure Redux applications yet. And I believe there’s no The Only True Project Structure but I’ll describe what works for me.

General structure

There are two approaches for grouping files:

• By type: one folder for components, one for reducers, one for actions, etc.
• By feature: all files related to one feature are inside the same folder.

I started from grouping by type. It works for a small application but to add a new feature you have to create: reducers/myfeature.js, selectors/myfeature.js, components/MyFeature.js and a few more. It’s annoying and difficult to explain to new team members.

Now I group files by view or page: dashboard, users, etc.

Here are main folders I have in my application:

• app: Redux store configuration and root reducer, React Router routes, application root components with connections to Redux, Redux DevTools, React Router and React Intl.
• components: shared components.
• models: Immutable.js records.
• util: any shared non-React JavaScript code.
• features.

Feature folders look like this:

features/
    feature-name/
        components/
            FeatureNameView.jsx
            FeatureNameLayout.jsx
            *.jsx
        duck.js
        selector.js
    very-big-feature/
        feature1/
        feature2/

• I follow the Ducks convention so instead of separate files for actions, reducers and constants there are single duck file. I also put Reselect selectors into the duck file as selector named export.
• The components folder contains all React components that are unique to this view.
• FeatureNameView is connected to Redux and contains all action calls. Nested components receive handlers as props and don’t know anything about Redux. All page layout goes to FeatureNameLayout component.

Ducks and selectors

Each feature has its own duck file duck.js structured as follows:

import { combineReducers } from 'redux';
import { createStructuredSelector } from 'reselect';
const DO_SOMETHING_COOL = 'myapp/feature-name/DO_SOMETHING_COOL';
// Actions
export function doSomethingCool(what) {
  return {
    type: DO_SOMETHING_COOL,
    // ...
  };
}
// Reducers
function cookiesReducer(state, action) {
  switch (action.type) {
    case DO_SOMETHING_COOL:
      return {/*_*/};
    default:
      return {/*_*/};
  }
}
export default combineReducers({
  cookies: cookiesReducer,
  // ...
});
// Selectors
const isFetching = state => state.isFetching;
const cookies = state => state.data.cookies;
export const selector = createStructuredSelector({
  isFetching,
  cookies,
});

Then import it at the root reducer, app/reducers.js:

import { combineReducers } from 'redux';
import featureName from '../components/feature-name/duck';
export default combineReducers({
  featureName,
  // ...
});

I use selectors as the only way to access Redux state in components. So I connect selectors and actions to feature’s root component, FeatureNameView.jsx:

import React, { Component, PropTypes } from 'react';
import { bindActionCreators } from 'redux';
import { connect } from 'react-redux';
import * as duck from '../duck';
import FeatureNameLayout from './FeatureNameLayout';
@connect(state => duck.selector(state.featureName), dispatch => ({
    actions: bindActionCreators(duck, dispatch),
}))
export default class FeatureNameView extends Component {
 /*
 Here you have:
 - this.props.actions.doSomethingCool
 - this.props.isFetching
 - this.props.cookies
 */
 
 handleSomethingCool(what) {
  this.props.actions.doSomethingCool(what);
 }
 
 render() {
   const { isFetching } = this.props;
   return (
     <div>
       {isFetching ? (
         <span>Loading...</span>
       ) : (
         <FeatureNameLayout
           {...this.props}
           onSomethingCool={what => this.handleSomethingCool(what)}
         />
       )}
     </div>
   ); 
 }
}

Components

For simple applications I like the simplest structure:

feature-one/
    Component1.js
    Component2.js
    Component2.css

It works fine until you add more styles and other non-JavaScript files to your components. In this case I’d put every component into a separate folder:

feature-one/
    Component1
        index.js
        Component1.js
        Component1.css
        Component1.spec.js

File names are still contain component class names so you can open them using a fuzzy search in your editor. I also have an extra entry file in every component folder, index.js:

export { default } from './Component1';

It allows you to import components like this: components/Component1 instead of components/Component1/Component1.

Development and production versions

In a few places I have separate files for development and production builds: containers/Root and store/configureStore, for example. I think they are easier to use then a single file with a bunch of ifs.

For example, configureStore.development.js and configureStore.production.js are completely independent modules and configureStore.js chooses which one to use:

if (process.env.NODE_ENV === 'production') {
    module.exports = require('./configureStore.production');
}
else {
    module.exports = require('./configureStore.development');
}

It allows you to do import configureStore from ./store/configureStore and have the right version of the module depending on the current environment.

Other approaches

• Structuring React Projects, a chapter from SurviveJS book.
• A Better File Structure For React/Redux Applications
• Organizing Large React Applications
• How to better organize your React applications?

P. S. Check out my latest open source project: React Styleguidist, a component style guide generator with a hot reload dev server.

Subscribe to my newsletter: https://tinyletter.com/sapegin