js

• This is the base set of eslint rules (and, consequently, style) for JavaScript at Evermind.
• Inspired by the many great style-guides out there, but particularly Zeit's and Airbnb's.

Principles (in priority order)

• Safe
• Readible
• Consistent
• Clean
• Brief
• Easy

Uses

• eslint -> For syntax and code issues, as well as some stylistic linting
• husky -> Manage githooks
• lint-staged -> Use with husky for automatic linting on git commit

Notes

• This is a work in progress and should be thought of as organic, rather than static. It is as much a tool to decide what the style should be as it is an enforcement and declaration of that style.
• If something should never be in your code, it is an error, regardless of the severity of the issue.
• If something probably shouldn't be in your code, but might just require extra oversight from the programmer, the rule should produce a warning. The programmer should then insert a comment to remove the error, or adjust the code accordingly. See the eslint docs for details.
• You should add rules here where possible, not in individual projects.

Usage

• Make sure you have eslint installed and initialised: npm --save-dev i eslint/yarn add --dev eslint
• Install with yarn (or npm)

  yarn add --dev @evermind/eslint-config-base

• You should extend this in your eslintrc.js.

  {
    'extends': '@evermind/eslint-config-base'
  }

  • See https://eslint.org/docs/developer-guide/shareable-configs for details.
• Add the following to your package.json scripts (adjusting for the appropriate src folder accordingly):

  "husky": {
    "hooks": {
      "pre-commit": "lint-staged"
    }
  },
  "lint-staged": {
    // note that lint-staged chooses the path for linting for you
    "*.{js,jsx}": [
      "yarn lint", 
      "git add"
    ]
  },
  "scripts": {
    "lint": "eslint ./src",
  }

• Setup your editor as necesary: https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint, https://github.com/w0rp/ale

Git Hooks

• This packagage assumes you are using githooks to run linting (hence the fact that husky and elint-staged are dependencies, although they do not technically need to be implemented).
• If you add to your package.json as specified above, you'll have automatic linting taken care of for you on each commit, for the files you are commiting only.

Flow

• If you have flow installed, you will also need to run yarn add --dev eslint-plugin-flowtype.
• You will then need to add the following to your .eslintrc.js:

  {
    'extends': [
      'plugin:flowtype/recommended',  
    ],
    'plugins': [
      'flowtype', 
    ],
  }

• You may also want to add some githooks for extra flow checking by adding flow --write to lint-staged in your package.json.

React

• If you are using react, you will also need to run yarn add --dev eslint-plugin-react
• Then add the following to your .eslnitrc.js:

  {
    'extends': [
      'plugin:react/recommended',  
    ],
    'plugins': [
      'react',
    ],
  }

Updating

1. Make appropriate changes in repo

• Ensure stylistic changes (i.e. overwrites of Prettier) go in styleRules.js.

2. npm version <update_type> (where update type is one of patch, minor, or major)
3. npm publish