fixes

Author: vasia

lib/compilers/postcss-compiler.js

@@ -4,6 +4,7 @@ const ctx = { parser: true, map: 'inline' }
 const { plugins } = postcssrc.sync(ctx)
 const logger = require('../logger')
 const getVueJestConfig = require('../get-vue-jest-config')
+const ensureRequire = require('../ensure-require')
 
 let prevCheckIsAsync = null
 function hasAsyncPlugin () {
@@ -41,6 +42,8 @@ function catchError (error, filePath, jestConfig) {
 }
 
 module.exports = (content, filePath, jestConfig) => {
+  ensureRequire('postcss', ['postcss'])
+
   let css = null
 
   const res = postcss(plugins)