test: fix vue.config.js tests

packages/@vue/cli-service/__tests__/Service.spec.js

@@ -1,5 +1,5 @@
 jest.mock('fs')
-jest.mock('mock-config', () => ({ lintOnSave: false }), { virtual: true })
+jest.mock('/vue.config.js', () => ({ lintOnSave: false }), { virtual: true })
 jest.mock('vue-cli-plugin-foo', () => () => {}, { virtual: true })
 
 const fs = require('fs')
@@ -53,16 +53,16 @@ test('load project options from package.json', () => {
 })
 
 test('load project options from vue.config.js', () => {
-  process.env.VUE_CLI_SERVICE_CONFIG_PATH = 'mock-config'
+  fs.writeFileSync('/vue.config.js', `module.exports = { lintOnSave: false }`)
   mockPkg({
     vue: {
       lintOnSave: true
     }
   })
   const service = createMockService()
+  fs.unlinkSync('/vue.config.js')
   // vue.config.js has higher priority
   expect(service.projectOptions.lintOnSave).toBe(false)
-  delete process.env.VUE_CLI_SERVICE_CONFIG_PATH
 })
 
 test('api: setMode', () => {

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

@@ -159,13 +159,11 @@ module.exports = class Service {
   loadProjectOptions (inlineOptions) {
     // vue.config.js
     let fileConfig, pkgConfig, resolved, resovledFrom
-    const configPath = (
-      process.env.VUE_CLI_SERVICE_CONFIG_PATH ||
-      path.resolve(this.context, 'vue.config.js')
-    )
+    const configPath = path.resolve(this.context, 'vue.config.js')
     if (fs.existsSync(configPath)) {
       try {
         fileConfig = require(configPath)
+        console.log(fileConfig)
         if (!fileConfig || typeof fileConfig !== 'object') {
           error(
             `Error loading ${chalk.bold('vue.config.js')}: should export an object.`