React Best Practices

This repo is for the purposes of a high-level view of React architecture and best practices. As this repo grows, more ideas will be introduced and comparisons will be made with pros and cons.

Being that this is a public repo, I hope that people will not only take what they can from the repo's information, but contribute as well. Feel free to submit pull requests and I will add your information to the document.

Forking this repo is great if you want to create your own repo with your decisions, using this as a starting point.

Architecture

Patterns

Flux Pattern
Flux explained
Redux

Render Props Pattern
https://medium.freecodecamp.org/how-to-develop-your-react-superpowers-with-the-render-props-pattern-b74e68c6d053

Functional Paradigm

Functional Programming

Immutability
- No side-effects
- Predictable data
Functional methods
- map/filter/reduce
  - w3Schools array fuctions

Pure Components

fn(state, props) == UI
Local state suggestions from: https://medium.com/@robftw/characteristics-of-an-ideal-react-architecture-883b9b92be0b
- No local state other than:
  - Animation/triggering of CSS Classes
  - UI control that doesn't involve business logic or dependent on other components
  - Extremely trivial UI related variables that won't cause side effects
  - Standalone libraries

Routing

React Router
https://github.com/ReactTraining/react-router

Guide:
https://reacttraining.com/react-router/web/guides/quick-start

State Structure

From: https://redux.js.org/recipes/structuring-reducers/normalizing-state-shape

Normalized data structures by Id (Relational Table Model)

{
  posts: {
    byId: {
      "post1" : {
        id: "post1"
        author: "author1"
        body: "..."
        comments: ["comment1", "comment2"]
      },
      "post2" : {
        id: "post2"
        author: "author2"
        body: "..."
        comments: ["comment3", "comment4", "comment5"]
      },
    },
    allIds: ["post1", "post2"],
  },
  comments: {
    byId: {
      "comment1": {
        id: "comment1",
        author: "user2",
        comment: "...",
      },
      "comment2": {
        id: "comment2",
        author: "user3",
        comment: "...",
      },
      "comment3": {
        id: "comment3",
        author: "user3",
        comment: "...",
      },
      "comment4": {
        id: "comment4",
        author: "user1",
        comment: "...",
      },
      "comment5": {
        id: "comment5",
        author: "user3",
        comment: "...",
      },
    },
    allIds: ["comment1", "comment2", "comment3", "comment4", "comment5"],
  },
  users: {
    byId: {
      "user1": {
        username: "user1",
        name: "User 1",
      },
      "user2": {
        username: "user2",
        name: "User 2",
      },
      "user3": {
        username: "user3",
        name: "User 3",
      },
    },
    allIds: ["user1", "user2", "user3"]
  },
  simpleDomainData1: {...},
  simpleDomainData2: {...},
}

Removes the deeply nested structures as your state grows in size and keeps components from re-rendering accidentally.

Folder Structure

.
├── /android/
├── /ios/
|
├── /assets
│   ├── /fonts/
│   ├── /images/
│   ├── /videos/
|
├── /app or /src
│   ├── /redux/  // See "Ducks"
│   ├── /scenes/
│   |   ├── /App/
│   |   |   ├── /_/
│   |   |   ├── /App.js
│   |   |   └── /index.js
|   |   ├── /MyScene/
|   |   |   ├── /__tests__/
|   |   |   ├── /_/
|   |   |   |   ├── /MySubcomponent/
|   |   |   |       ├── /__tests__/
|   |   |   |       ├── /MySubcomponent.js
│   |   |   |       └── /index.js
│   |   |   ├── /MyScene.js
│   |   |   └── /index.js
│   ├── /shared/
|   |   ├── /SharedAppSpecificComponent/
|   |       ├── /__tests__/
|   |       ├── /SharedAppSpecificComponent.js
|   |       └── /index.js
│   └── /types/
|
|
├── /lib
|   ├── /Button/
|       ├── /__tests__/
|       ├── /Button.js
|       └── /index.js
|
├── /tools/  //Build scripts, other tools
├── /node_modules/
└── package.json

https://github.com/kylpo/react-playbook/blob/master/component-architecture/5_Example-App-Structure.md

/lib/ explanation: Every component that is not "app specific" or a primitive component can be a candidate to be moved to the /lib/ folder. This allows for the possible side effect of hand-rolling your own component library as you code!

Primitive components are those that take in only primitives as their props and are functionally pure.

Redux "Ducks"

.
├── /redux/
    └── /MyDuck/
    |   ├── /__tests__/
    |   ├── actions.js
    |   ├── index.js
    |   ├── operations.js
    |   ├── reducers.js
    |   ├── selectors.js
    |   ├── types.js
    |   └── utils.js
    └── commonTypes.js

https://medium.freecodecamp.org/scaling-your-redux-app-with-ducks-6115955638be

Best Practices and Coding Style

Naming Convention

Components

From: https://hackernoon.com/react-components-naming-convention-%EF%B8%8F-b50303551505

[Domain]|[Page/Context]|ComponentName|[Type]

Examples:

ACommunityAddToShortListButton - [Domain][ComponentName][Type]
SideBar - [ComponentName]
SideBarSwitch - [ComponentName][Type]
ChatConversation - [Page/Context][ComponentName]
ChatConversationName - [Page/Context][ComponentName]

Component Creation

Write a stateless functional component first
- if (component requires state or life-cycle) Make stateful class
- if (component is comprised of multiple components or smaller pieces of functionality) Create container component
- Move shared components out
  - if (app dependent) Keep in shared/MyComponent
  - if (!app dependent or primitive) Move to lib folder
Avoid re-rendering component if possible

Styling

SASS
https://sass-lang.com/

Gives you the ability to nest your CSS, create mixins, among other things.

Guide for SASS in React:
https://hugogiraudel.com/2015/06/18/styling-react-components-in-sass/

Styled Components
https://www.styled-components.com/

Scope your styles on a component level, directly in your JS file. Allows for computing styles at a functional level in JS rather than relying on pre-compilers.

Testing

Libraries

Jest
https://jestjs.io/

Most popular React testing library. Comes with snapshot comparisons which is very useful for testing pure components.

Sinon
https://sinonjs.org/

Spies, stubs and mocks

Strategies

From: https://github.com/kylpo/react-playbook/blob/master/best-practices/react.md

Write component tests that accomplish the following goals (from Getting Started with TDD in React)

It renders
It renders the correct thing
- Default props
- Varied props
It renders the different states
Test events
Test edge cases
- e.g. something that uses an array should be thrown an empty array

Build and Deploy

Starter kits

https://reactjs.org/community/starter-kits.html

This list contains many popular choices, but your choice is yours. Getting a good starter kit depends entirely on what you're looking to get out of your project and team.

Build Libraries

Babel
https://babeljs.io/

Transpiles your javascript down from the latest standards to backwards compatible, browser friendly source. Used for transpiling JSX to JS.

Webpack
https://webpack.js.org/

Bundles your files into static assets that are ready for production deploy. Many extensible plugins available.

ESLint
https://eslint.org/

Keeps your code nice and tidy by yelling at you with squigglies. You can link this to your IDE.

Great ESLint configs:
prettier-eslint
eslint-config-airbnb

Libraries

Form Helpers

Redux Forms
https://redux-form.com/8.1.0/

Uses Redux to maintain the state of your forms through custom components, abstracted actions and reducers.

Formik
https://github.com/jaredpalmer/formik

Creates an ephemeral state held by its components that abstracts away all the boilerplate that goes into creating and maintaining forms.

State Management Helpers

Reselect
https://github.com/reduxjs/reselect

Creates a selector where the first functions passed in compute props for a final function. If none of those props have changed, then that function is not run and the result from the previous invocation is returned.

This keeps the state from needlessly causing components to re-render.

Normalizr
https://github.com/paularmstrong/normalizr

Especially useful for taking in schemas of data input and producing an "entities" object and a "result" object. "Entities" is of the structure above in "State Structure" where it is a normalized relational list. "Result" is the list of ids.

redux-orm
https://github.com/tommikaikkonen/redux-orm

Library that creates Object Relational Mapping (ORM) using the aforementioned structure.

Guide to using redux-orm and Redux structuring as a whole:
https://blog.isquaredsoftware.com/series/practical-redux/

Styling

classnames
https://github.com/JedWatson/classnames

Takes in conditionals that returns a space-delimited string for className.

import classnames from 'classnames';

let classes = classnames('sd-date', {
  current: date.month() === this.props.month,
  future: date.month() > this.props.month,
  past: date.month() < this.props.month
});

return (
  <button className={classes} />

  vs

  <button className={`button-default-style ${isActive ? "active" : ""}`} />
);

Functional Programming Helpers

Ramda
https://github.com/ramda/ramda

Emphasizes pure functional code. Functions written in Ramda are pure and side-effect free, making them easy to test. They are also automatically curried, giving you the ability to partially apply parameters and pass back a new function.

Currying explanation: Why Curry Helps

Miscellaneous Helpers

date-fns
https://date-fns.org/

Date/Time formatting with a functional paradigm and localization.

Moment
https://github.com/moment/moment/

Date/Time related formatting

IDEs

Visual Studio Code
https://code.visualstudio.com/

Microsoft has opensourced this light-weight and highly extensible IDE. My personal favorite.

Atom
https://atom.io/

Another IDE that is also very popular amoung web devs.

Roadmaps and Future Functionality

React 16.x
https://reactjs.org/blog/2018/11/27/react-16-roadmap.html

Things to look forward to:

Suspense
- Fallback component while a component is rendering. E.g. abstracts need for loading gifs.
Hooks
- Add state to function components. Improves optimizing at scale and removes need for "wrapper hell"
Concurrent
- Prioritize renders