Default ESlint for OnBrand Developer

These are our settings for ESLint and Prettier

What it does

• Lints JavaScript and TypeScript based on the latest standards
• Fixes issues and formatting errors with Prettier
• Lints + Fixes inside of html script tags
• Lints + Fixes React via eslint-config-airbnb
• You can see all the rules here - these generally abide by the code written in my courses. You are very welcome to overwrite any of these settings, or just fork the entire thing to create your own.

Project Install

It's recommended you install this once per every project. ESLint used to have global configs, but no longer.

1. If you don't already have a package.json file, create one with npm init -y.

2. Then we need to install this config

npm install eslint-config-onbrand

4. We need to put our eslint settings in a file in the root of your project. I prefer to use our existing package.json, and add an eslintConfig property. You can also create a new .eslintrc or .eslintrc.js file that lives where package.json does:

in package.json, add this anywhere top level. Like right under your "scripts" object.

"eslintConfig": {
  "extends": ["onbrand"]
}

Or put this in a .eslintrc file

{
  "extends": ["onbrand"]
}

For TypeScript projects, use onbrand/typescript.

{
  "extends": ["onbrand/typescript"]
}

5. You can add two scripts to your package.json to lint and/or fix:

"scripts": {
  "lint": "eslint .",
  "lint:fix": "eslint . --fix"
},

6. Now you can manually lint your code by running npm run lint and fix all fixable issues with npm run lint:fix. You probably want your editor to do this though.

Settings

If needed, to overwrite eslint or prettier settings, you can add the rules in your .eslintrc file. The ESLint rules go directly under "rules".

{
  "extends": [
    "onbrand"
  ],
  "rules": {
    "no-console": 2,
  }
}

Prettier Rules

If you want custom prettier options, add a .prettierrc file in the root directory and override any of the preset values:

{
  "endOfLine": "auto",
  "trailingComma": "all",
  "tabWidth": 2,
  "semi": true,
  "singleQuote": false,
  "bracketSpacing": false,
  "arrowParens": "always",
}

You can also put this in the EsLint config as a rule like so:

{
  "extends": ["onbrand"],
  "rules": {
    ... any eslint rules here
    "prettier/prettier": [
      "error",
      {
        "endOfLine": "auto",
        "tabWidth": 4
      },
    ],
  }
}

With VS Code

You should read this entire thing. Serious!

Once you have done one, or both, of the above installs. You probably want your editor to lint and fix for you. Here are the instructions for VS Code:

1. Install the ESLint package
2. Now we need to setup some VS Code settings via Code/File → Preferences → Settings. It's easier to enter these settings while editing the settings.json file, so click the Open (Open Settings) icon in the top right corner:

// These are all my auto-save configs
"editor.formatOnSave": true,
// turn it off for JS and JSX, we will do this via eslint
"[javascript][javascriptreact][typescript][typescriptreact]": {
  "editor.formatOnSave": false
},
// show eslint icon at bottom toolbar
"eslint.alwaysShowStatus": true,
// tell the ESLint plugin to run on save
"editor.codeActionsOnSave": {
  "source.fixAll": true
}

After attempting to lint your file for the first time, you may need to click on 'ESLint' in the bottom right and select 'Allow Everywhere' in the alert window.

Finally you'll usually need to restart VS code. They say you don't need to, but it's never worked for me until I restart.

With Typescript

Same instructions as above, just make sure you extend onbrand/typescript instead of just onbrand.

Issues with ESLint not formatting code

If you experience issues with ESLint not formatting the code or you receive a Parsing error: Cannot find module '@babel/preset-react error message then you need to check that you opened the folder where you installed and configured ESLint directly in VS Code. The correct folder to open will be the one where you installed the eslint-config-onbrand npm package and where you created the .eslintrc file.

Opening a parent folder or child folder in your code editor will cause ESLint to fail in finding the ESLint npm packages and the formatting won't work.

your-username
  |
  projects
    |
    beginner-javascript # <- Open this folder directly in your code editor
      .eslintrc
      package.json
      node_modules/
      exercises/
      playground/