@conduitvc/airbnb-base

Neutrino preset that supports linting Node.js projects with Airbnb's ESLint config, following the Airbnb styleguide, with Conduit's stylistic preferences.

Features

• Zero upfront configuration necessary to start linting your project
• Modern Babel knowledge supporting ES modules and optionally Flow and TypeScript
• Highly visible during development, fails compilation when building for production
• Easily extensible to customize as needed

Note: If you are building a React project, you should probably use @conduitvc/airbnb instead.

Requirements

• Node.js ^8.10 or 10+
• Yarn v1.2.1+, or npm v5.4+
• Neutrino 9 and one of the Neutrino build presets
• ESLint 5

Setup

In your project, install the necessary development dependencies:

Note: You should already have neutrino@next installed via your build preset.

yarn add --dev @conduitvc/airbnb-base eslint

After adding the Airbnb preset to your Neutrino-built project, edit your project's .neutrinorc.js to add the preset for linting before your build preset. For example, when building your project using @conduitvc/node:

module.exports = {
  options: {
    root: __dirname,
  },
  use: [
    '@conduitvc/airbnb-base',
    '@conduitvc/node',
  ],
};

Start the app, then check your console for any linting errors. If everything is successful, you should see no errors in the console. ESLint errors visible during development are reported, but will still continue to build and serve your project. ESLint errors during build will not build the project, and will cause the command to fail.

❯ yarn start

ERROR in ./src/index.js
Module Error (from ./node_modules/eslint-loader/index.js):

error: Missing semicolon (semi) at src/index.js:35:29:
  33 |
  34 |
> 35 | const HOST = 'localhost:3000'
     |                              ^
  36 |
  37 |
  38 |

1 error found.
1 error potentially fixable with the `--fix` option.

Building

@conduitvc/airbnb-base will cause errors to fail your build when NODE_ENV is not 'development'. If you want to ease introduction of this linting preset to your project, consider only adding it to your use list during development until all linting errors have been resolved.

❯ yarn build

ERROR in ./src/index.js
Module Error (from ./node_modules/eslint-loader/index.js):

error: Missing semicolon (semi) at src/index.js:35:29:
  33 |
  34 |
> 35 | const HOST = 'localhost:3000'
     |                              ^
  36 |
  37 |
  38 |

1 error found.
1 error potentially fixable with the `--fix` option.

Example: ease linting into project by only enabling when NODE_ENV=development, i.e., --mode development:

module.exports = {
  options: {
    root: __dirname,
  },
  use: [
    process.env.NODE_ENV === 'development' ? '@conduitvc/airbnb-base' : false,
    '@conduitvc/node',
  ],
};

Middleware options

This preset uses the same middleware options as @neutrinojs/eslint. If you wish to customize what is included, excluded, or any ESLint options, you can provide an options object with the middleware and this will be merged with our internal defaults for this preset. Use an array pair instead of a string to supply these options.

Example: Extend from a custom configuration (it will be applied after Airbnb) and turn off semicolons from being required.

module.exports = {
  options: {
    root: __dirname,
  },
  use: [
    ['@conduitvc/airbnb-base', {
      eslint: {
        // For supported options, see:
        // https://github.com/webpack-contrib/eslint-loader#options
        // https://eslint.org/docs/developer-guide/nodejs-api#cliengine
        // The options under `baseConfig` correspond to those
        // that can be used in an `.eslintrc.*` file.
        baseConfig: {
          extends: [
            'my-custom-config',
          ],
          rules: {
            'babel/semi': 'off',
          },
        },
      },
    }],
  ],
};

Flow Support

To enable linting with Flow syntax support, specify the flow: true option to the preset:

module.exports = {
  options: {
    root: __dirname,
  },
  use: [
    ['@conduitvc/airbnb-base', {
      flow: true,
    }],
  ],
};

TypeScript Support

To enable linting with TypeScript syntax support, specify the typescript: true option to the preset:

module.exports = {
  options: {
    root: __dirname,
  },
  use: [
    ['@conduitvc/airbnb-base', {
      typescript: true,
    }],
  ],
};

Exposing generated lint configuration via .eslintrc.js

@neutrinojs/eslint, from which this preset inherits, provides an .eslintrc() output handler for generating the ESLint configuration in a format suitable for use in an .eslintrc.js file. This allows the ESLint CLI to be used outside of building the project, and for IDEs and text editors to provide linting hints and fixes.

Create a .eslintrc.js file in the root of the project, containing:

// .eslintrc.js
const neutrino = require('neutrino');

module.exports = neutrino().eslintrc();

This .eslintrc.js configuration will be automatically used when running the ESLint CLI. For convenience a lint script alias can be added to your package.json, allowing linting to be run via yarn lint:

{
  "scripts": {
    "lint": "eslint --cache --format codeframe src"
  }
}

Projects may face a problem when their editor or IDE lints all files and highlights errors that were normally excluded from source, i.e. Neutrino's include and exclude options. This is because the ESLint CLI does not have a way to specify included and excluded files from the .eslintrc.js configuration. Instead you will need to create an .eslintignore file that controls which files should be excluded from linting.

Using your own .eslintrc.*

If instead you would prefer to use your own non-generated .eslintrc.* file, set useEslintrc to true. This will cause @conduitvc/airbnb-base to only set the loader-specific configuration defaults, and leave all other linting configuration to be managed by the standalone .eslintrc.* file.

See the @neutrinojs/eslint documentation for more details.