Cause of the problem: the project uses eslint specification code, and your code violates the specification

The first scheme (recommended): format the code through the editor and unify the indentation method

The second method: turn off the verification of spaces and tabs by eslin
Vue version 3.0:
1, find build – & gt; webpack.base.config.js。 Comment or remove the reference to eslint loader.

{
      test: /\.(js|vue)$/,
      loader: 'eslint-loader',
      enforce: 'pre',
      include: [resolve('src'), resolve('test')],
      options: {
        formatter: require('eslint-friendly-formatter'),
        emitWarning: !config.dev.showEslintErrorsInOverlay
      }
}

2. Restart the project

Vue 3.0 +:
configure the rules of eslin in package.json. Eslintconfig

 {
      "name": "xxxx",
      "version": "0.1.0",
      "private": true,
      "scripts": {
        "serve": "vue-cli-service serve",
        "build": "vue-cli-service build",
        "lint": "vue-cli-service lint"
      },
      "dependencies": {
        xxx
      },
      "devDependencies": {
       xxx
      },
     
      "eslintConfig": {
        "root": true,
        "env": {
          "node": true
        },
        "extends": [
          "plugin:vue/essential",
          "eslint:recommended"
        ],
        "parserOptions": {
          "parser": "babel-eslint"
        },
        "rules": {
          "no-console": "off",
          "no-debugger": "off",
          "no-mixed-spaces-and-tabs": "off"
        }
     
      },
      "browserslist": [
        "> 1%",
        "last 2 versions",
        "not dead"
      ]
 }

The third other method:
create a vue.config.js

module.exports = {
	lintOnSave:false 
}