Add eslint interview questions and answers

Author: sudheerj

README.md

@@ -132,6 +132,9 @@ List of 300 VueJS Interview Questions
 |123| [How to create functional components using vue loader?](#how-to-create-functional-components-using-vue-loader)|
 |124| [How do you access global properties of functional components?](#how-do-you-access-global-properties-of-functional-components)|
 |125| [How do you perform testing in vuejs?](#how-do-you-perform-testing-in-vuejs)|
+|126| [How do you apply linting for css?](#how-do-you-apply-linting-for-css)|
+|127| [How do you use eslint plugin?](#how-do-you-use-eslint-plugin)|
+|128| [What is the purpose of eslint loader?](#what-is-the-purpose-of-eslint-loader)|
 
 1. ### What is VueJS?
  **Vue.js** is an open-source, progressive Javascript framework for building user interfaces that aim to be incrementally adoptable. The core library of VueJS is focused on the `view layer` only, and is easy to pick up and integrate with other libraries or existing projects.
@@ -2314,4 +2317,58 @@ List of 300 VueJS Interview Questions
 125. ### How do you perform testing in vuejs?
  You can perform testing in two ways,
  1. ** Using vue-cli:** It offers pre-configured unit testing and e2e testing setups
- 2. ** Manual setup:** You can manually setting up unit tests for *.vue files using either mocha-webpack or jest
+ 2. ** Manual setup:** You can manually setting up unit tests for *.vue files using either mocha-webpack or jest
+126. ### How do you apply linting for css?
+ The stylelint linter supports linting style parts of Vue single file components. You can run linter on particular vue file as below
+ ```javascript
+ stylelint MyComponent.vue
+ ```
+ Other option is configuring stylelint-webpack-plugin in webpack. It can be configured as a dev dependency.
+ ```javascript
+ // webpack.config.js
+ const StyleLintPlugin = require('stylelint-webpack-plugin');
+ module.exports = {
+ // ... other options
+ plugins: [
+ new StyleLintPlugin({
+ files: ['**/*.{vue,htm,html,css,sss,less,scss,sass}'],
+ })
+ ]
+ }
+ ```
+127. ### How do you use eslint plugin?
+ The official `eslint-plugin-vue` supports linting both the template and script parts of Vue single file components. You can configure plugin in your ESLint config,
+ ```javascript
+ // .eslintrc.js
+ module.exports = {
+ extends: [
+ "plugin:vue/essential"
+ ]
+ }
+ ```
+ You can run linter on particular component as below,
+ ```javascript
+ eslint --ext js,vue MyComponent.vue
+ ```
+128. ### What is the purpose of eslint loader?
+ You can use `eslint-loader` for *.vue files in order to automatically linted on save during development. It can be installed as npm module,
+ ```javascript
+ npm install -D eslint eslint-loader
+ ```
+ After that you need to add it as pre-loader,
+ ```javascript
+ // webpack.config.js
+ module.exports = {
+ // ... other options
+ module: {
+ rules: [
+ {
+ enforce: 'pre',
+ test: /\.(js|vue)$/,
+ loader: 'eslint-loader',
+ exclude: /node_modules/
+ }
+ ]
+ }
+ }
+ ```