Add setting to disable linter if project uses ESLint

lib/init.js

@@ -16,6 +16,12 @@ module.exports = {
       description: 'Only run if standard, semistandard or happiness present in package.json `devDependencies`',
       default: false
     },
+    checkForEslintConfig: {
+      type: 'boolean',
+      title: 'Disable if the project uses ESLint',
+      description: 'Do not run if the project has configured ESLint',
+      default: true
+    },
     honorStyleSettings: {
       type: 'boolean',
       description: 'Honor code style settings on package.json',
@@ -98,7 +104,8 @@ module.exports = {
 
     var style = selectStyle(filePath, {
       style: opts.style || config.style,
-      checkStyleDevDependencies: config.checkStyleDevDependencies
+      checkStyleDevDependencies: config.checkStyleDevDependencies,
+      checkForEslintConfig: config.checkForEslintConfig
     })
 
     // Cache style settings and args of some file

lib/utils/select-style.js

@@ -1,5 +1,6 @@
 var allowUnsafeNewFunction = require('loophole').allowUnsafeNewFunction
 var pkgConfig = require('pkg-config')
+var detectEslintConfig = require('detect-eslint-config')
 var dirname = require('path').dirname
 var styleSettings = require('./style-settings')
 
@@ -48,6 +49,11 @@ function getStyleThroughDevDeps (filePath, style) {
 }
 
 module.exports = function selectStyle (filePath, options) {
+  // Return early if the project uses ESLint
+  if (options.checkForEslintConfig && detectEslintConfig(filePath)) {
+    return noStyle()
+  }
+
   // See if it should get style from the package.json
   if (options.checkStyleDevDependencies) {
     return getStyleThroughDevDeps(filePath, options.style)

package.json

@@ -21,6 +21,7 @@
   "dependencies": {
     "atom-package-deps": "^4.6.0",
     "babel-eslint": "^7.1.0",
+    "detect-eslint-config": "^0.5.6",
     "eslint-rule-documentation": "^1.0.9",
     "esprima": "^3.1.1",
     "happiness": "^10.0.2",