Add e2e test for metalsmith custom plugin

Author: Toilal

Diff for: test/e2e/mock-metalsmith-custom/meta.js

@@ -0,0 +1,17 @@
+module.exports = {
+  "metalsmith": function (metalsmith, opts, helpers) {
+    function customMetalsmithPlugin (files, metalsmith, done) {
+      // Implement something really custom here.
+
+      var readme = files['readme.md']
+      delete files['readme.md']
+      files['custom/readme.md'] = readme
+
+      console.log(files)
+
+      done(null, files)
+    }
+
+    metalsmith.use(customMetalsmithPlugin)
+  }
+}

Diff for: test/e2e/mock-metalsmith-custom/template/readme.md

@@ -0,0 +1 @@
+Metalsmith

Diff for: test/e2e/test.js

@@ -13,6 +13,7 @@ const metadata = require('../../lib/options')
 const { isLocalPath, getTemplatePath } = require('../../lib/local-path')
 
 const MOCK_META_JSON_PATH = path.resolve('./test/e2e/mock-meta-json')
+const MOCK_METALSMITH_CUSTOM = path.resolve('./test/e2e/mock-metalsmith-custom')
 const MOCK_TEMPLATE_REPO_PATH = path.resolve('./test/e2e/mock-template-repo')
 const MOCK_TEMPLATE_BUILD_PATH = path.resolve('./test/e2e/mock-template-build')
 const MOCK_METADATA_REPO_JS_PATH = path.resolve('./test/e2e/mock-metadata-repo-js')
@@ -120,6 +121,16 @@ describe('vue-cli', () => {
     })
   })
 
+  it('supports custom metalsmith plugins', done => {
+    generate('test', MOCK_METALSMITH_CUSTOM, MOCK_TEMPLATE_BUILD_PATH, err => {
+      if (err) done(err)
+
+      expect(exists(`${MOCK_TEMPLATE_BUILD_PATH}/custom/readme.md`)).to.equal(true)
+
+      done()
+    })
+  })
+
   it('generate a vaild package.json with escaped author', done => {
     monkeyPatchInquirer(escapedAnswers)
     generate('test', MOCK_TEMPLATE_REPO_PATH, MOCK_TEMPLATE_BUILD_PATH, err => {
@@ -254,7 +265,7 @@ describe('vue-cli', () => {
     expect(getTemplatePath('../template')).to.equal(path.join(__dirname, '/../../../template'))
   })
 
-  it.only('points out the file in the error', done => {
+  it('points out the file in the error', done => {
     monkeyPatchInquirer(answers)
     generate('test', MOCK_ERROR, MOCK_TEMPLATE_BUILD_PATH, err => {
       expect(err.message).to.match(/^\[readme\.md\] Parse error/)