ESLint only target a specific directory (eslintrc, create-react-app)

inside your .eslintrc.json

{
  "rules": {
    "quotes": [ 2, "double" ]
  },

  "overrides": [
    {
      "files": [ "src/**/*.js" ],
      "rules": {
        "quotes": [ 2, "single" ]
      }
    }
  ]
}

in .eslintignore

 /someFolder
 /anotherFolder
 /oneMoreFolder