For study eslint

Ref:

https://www.youtube.com/watch?v=nxxl2H_TOTc&list=PLMWjeRChIK6bnp6qaS3rxLGCpc9aQYzEE
Check git log for steps to using eslint

Example:

{
  "extends": "airbnb",
  "parserOptions": {
    "ecmaVersion": 6
  },
  "env": {
    "node": true,
    "es6": true,
    "browser": true
  },
  "rules": {
    "comma-dangle":["error", "never"],
    "no-unused-vars": ["error", 
      {
        "vars": "local",
        "args": "none"
      }
    ],
    "react/jsx-filename-extension": [1, {
      "extensions": [".js", ".jsx"]
    }]
  }
}

1. Install eslint as a Dev dependence, .node_modules/.bin added in .bashrc so can run local modules from current directory

2. Custom eslint config by extends eslint:recommended. extends work like inheritence in programming, with this we have all setting from eslint:recommended

3. Custom eslint to add parserOptions and env.

   • parserOptions: to config js version, here ecmascript version 6
   • env: to config execution environment which to has access to global variables on that environment like set browser env to has access to document object

4. Install eslint extension for VSCode, this extension expect two thing to work

   • eslint module installed globally or locally (locally in this case)
   • .eslintrc config file in project directory

5. Install eslint airbnb config and extends it

6. To customize eslint rules:

   • when using build-in rules: https://eslint.org/docs/rules/
   • When using eslint rules from plugin like react: google search for its name