standard-engine

Standard Engine

Overview

Wrap your own eslint rules in a easy-to-use command line tool and/or a JS module.

Install

npm install standard-engine

Who is using standard-engine?

Here is a list of packages using standard-engine. Dive into them for ideas!

• standard - JavaScript Standard Style.
• semistandard - Its standard with semicolons sprinkled on top.
• happiness - JavaScript Happiness Style (semicolons and tabs)
• doublestandard - Require TWO semicolons at the end of every line!
• strict-standard - Standard Style with strict error checking.

Did you make your own? Create a pull request and we will add it to the README!

Usage

Create the files below and fill in your own values for options.js.

index.js

// programmatic usage
var Linter = require('standard-engine').linter
var opts = require('./options.js')
module.exports = new Linter(opts)

cli.js

#!/usr/bin/env node

var opts = require('../options.js')
require('standard-engine').cli(opts)

options.js

var eslint = require('eslint')
var path = require('path')
var pkg = require('./package.json')

module.exports = {
  // homepage, version and bugs pulled from package.json
  version: pkg.version,
  homepage: pkg.homepage,
  bugs: pkg.bugs.url,
  eslint: eslint, // pass any version of eslint >= 1.0.0
  cmd: 'pocketlint', // should match the "bin" key in your package.json
  tagline: 'Live by your own standards!', // displayed in output --help
  eslintConfig: {
    configFile: path.join(__dirname, 'eslintrc.json')
  },
  cwd: '', // current working directory, passed to eslint

  // These are optional. If included, the --format option will be made available
  formatter: require('pocketlint-format'), // note you'll have to create this :)
  formatterName: 'pocketlint-format'
}

eslintrc.json Put all your .eslintrc rules in this file. A good practice is to create an ESLint Shareable Config and extend it, but its not required:

{
  // pretend that the package eslint-config-pocketlint exists!
  "extends": ["pocketlint"]
}

Take a look at eslint-config-standard as an example, or if you want to extend/mutate standard, see eslint-config-semistandard.

Engine Features

Ignoring Files

The paths node_modules/**, *.min.js, bundle.js, coverage/**, hidden files/folders (beginning with .), and all patterns in a project's root .gitignore file are automatically ignored.

Sometimes you need to ignore additional folders or specific minfied files. To do that, add a ignore property to package.json:

"pocketlint": { // this key should equal the value of cmd in options.js
  "ignore": [
    "**/out/",
    "/lib/select2/",
    "/lib/ckeditor/",
    "tmp.js"
  ]
}

Hiding Warnings

Since standard-engine uses eslint under-the-hood, you can hide warnings as you normally would if you used eslint directly.

To get verbose output (so you can find the particular rule name to ignore), run:

$ pocketlint --verbose
Error: Live by your own standards!
  routes/error.js:20:36: 'file' was used before it was defined. (no-use-before-define)

Disable all rules on a specific line:

file = 'I know what I am doing' // eslint-disable-line

Or, disable only the "no-use-before-define" rule:

file = 'I know what I am doing' // eslint-disable-line no-use-before-define

Or, disable the "no-use-before-define" rule for multiple lines:

/*eslint-disable no-use-before-define */
// offending code here...
// offending code here...
// offending code here...
/*eslint-enable no-use-before-define */

Defining Globals in a project's package.json

standard-engine will also look in a project's package.json and respect any global variables defined like so:

{
  "pocketlint": { // this key should equal the value of cmd in options.js
    "global": [ "myVar1", "myVar2" ]
  }
}

Custom JS parsers for bleeding-edge ES6 or ES7 support?

standard-engine supports custom JS parsers. To use a custom parser, install it from npm (example: npm install babel-eslint) and add this to your package.json:

{
  "pocketlint": { // this key should equal the value of cmd in your options.js
    "parser": "babel-eslint"
  }
}

If you're using your custom linter globally (you installed it with -g), then you also need to install babel-eslint globally with npm install babel-eslint -g.

API Usage

standardEngine.lintText(text, [opts], callback)

Lint the provided source text to enforce your defined style. An opts object may be provided:

{
  globals: [],  // global variables to declare
  parser: ''    // custom js parser (e.g. babel-eslint)
}

The callback will be called with an Error and results object:

{
  results: [
    {
      filePath: '',
      messages: [
        { ruleId: '', message: '', line: 0, column: 0 }
      ],
      errorCount: 0,
      warningCount: 0
    }
  ],
  errorCount: 0,
  warningCount: 0
}

standardEngine.lintFiles(files, [opts], callback)

Lint the provided files globs. An opts object may be provided:

{
  globals: [],  // global variables to declare
  parser: '',   // custom js parser (e.g. babel-eslint)
  ignore: [],   // file globs to ignore (has sane defaults)
  cwd: ''       // current working directory (default: process.cwd())
}

The callback will be called with an Error and results object (same as above).