feat: lintOnSave no longer causes compilation to fail

close #817

Author: yyx990803

docs/config.md

@@ -17,7 +17,9 @@ module.exports = {
   outputDir: 'dist',
 
   // whether to use eslint-loader for lint on save.
-  lintOnSave: false,
+  // valid values: true | false | 'error'
+  // when set to 'error', lint errors will cause compilation to fail.
+  lintOnSave: true,
 
   // use the full build with in-browser compiler?
   // https://vuejs.org/v2/guide/installation.html#Runtime-Compiler-vs-Runtime-only

packages/@vue/cli-plugin-eslint/__tests__/eslintGenerator.spec.js

@@ -98,10 +98,8 @@ test('lint on save', async () => {
       lintOn: 'save'
     }
   })
-
-  expect(pkg.vue).toEqual({
-    lintOnSave: true
-  })
+  // lintOnSave defaults to true so no need for the vue config
+  expect(pkg.vue).toBeFalsy()
 })
 
 test('lint on commit', async () => {
@@ -118,4 +116,7 @@ test('lint on commit', async () => {
     '*.js': ['vue-cli-service lint', 'git add'],
     '*.vue': ['vue-cli-service lint', 'git add']
   })
+  expect(pkg.vue).toEqual({
+    lintOnSave: false
+  })
 })

packages/@vue/cli-plugin-eslint/generator.js

@@ -42,9 +42,9 @@ module.exports = (api, { config, lintOn = [] }) => {
     })
   }
 
-  if (lintOn.includes('save')) {
+  if (!lintOn.includes('save')) {
     pkg.vue = {
-      lintOnSave: true // eslint-loader configured in runtime plugin
+      lintOnSave: false // eslint-loader configured in runtime plugin
     }
   }
 

packages/@vue/cli-plugin-eslint/index.js

@@ -13,6 +13,7 @@ module.exports = (api, { lintOnSave }) => {
           .use('eslint-loader')
             .loader('eslint-loader')
             .options(Object.assign(options, {
+              emitWarning: lintOnSave !== 'error',
               formatter: require('eslint/lib/formatters/codeframe')
             }))
     })

packages/@vue/cli-plugin-typescript/index.js

@@ -81,7 +81,7 @@ module.exports = (api, {
       .plugin('fork-ts-checker')
         .use(require('fork-ts-checker-webpack-plugin'), [{
           vue: true,
-          tslint: lintOnSave,
+          tslint: lintOnSave !== false,
           formatter: 'codeframe',
           // https://github.com/TypeStrong/ts-loader#happypackmode-boolean-defaultfalse
           checkSyntacticErrors: useThreads

packages/@vue/cli-service/lib/options.js

@@ -33,7 +33,7 @@ const schema = createSchema(joi => joi.object({
   ),
 
   // known runtime options for built-in plugins
-  lintOnSave: joi.boolean(),
+  lintOnSave: joi.any().valid([true, false, 'error']),
   pwa: joi.object(),
 
   // 3rd party plugin options
@@ -76,7 +76,7 @@ exports.defaults = () => ({
   },
 
   // whether to use eslint-loader
-  lintOnSave: false,
+  lintOnSave: true,
 
   devServer: {
   /*