test(custom-dirs): fix custom-asset dir test (#4136)

test/fixtures/custom-dirs/nuxt.config.js

@@ -1,4 +1,24 @@
 export default {
+  build: {
+    extractCSS: true,
+    optimization: {
+      splitChunks: {
+        name: true
+      }
+    },
+    postcss: {
+      preset: {
+        autoprefixer: {
+          grid: true
+        }
+      }
+    },
+    filenames: {
+      css: () => {
+        return '[name].css'
+      }
+    }
+  },
   css: [{ src: '~/custom-assets/app.css' }],
   dir: {
     assets: 'custom-assets',

test/unit/custom-dirs.test.js

@@ -1,4 +1,7 @@
-import { loadFixture, getPort, Nuxt, rp } from '../utils'
+import { resolve } from 'path'
+import { promisify } from 'util'
+import fs from 'fs'
+import { getPort, loadFixture, Nuxt, rp } from '../utils'
 
 let port
 const url = route => 'http://localhost:' + port + route
@@ -13,9 +16,13 @@ describe('custom-dirs', () => {
     await nuxt.listen(port, 'localhost')
   })
 
-  test.skip('custom assets directory', async () => {
-    const { html } = await nuxt.renderRoute('/')
-    expect(html).toContain('.global-css-selector')
+  test('custom assets directory', async () => {
+    const readFile = promisify(fs.readFile)
+
+    const extractedIndexCss = resolve(__dirname, '..', 'fixtures/custom-dirs/.nuxt/dist/client/app.css')
+    const content = await readFile(extractedIndexCss, 'utf-8')
+
+    expect(content).toContain('.global-css-selector{color:red}')
   })
 
   test('custom layouts directory', async () => {