fix(nightwatch): should not install corresponding webdriver if the br…

…owser is unselected (#5528)

packages/@vue/cli-plugin-e2e-nightwatch/generator/index.js

@@ -1,30 +1,33 @@
 const { installedBrowsers } = require('@vue/cli-shared-utils')
 
-module.exports = api => {
+module.exports = (api, { webdrivers }) => {
   api.render('./template', {
     hasTS: api.hasPlugin('typescript'),
     hasESLint: api.hasPlugin('eslint')
   })
 
+  const devDependencies = {}
+
   // Use devDependencies to store latest version number so as to automate update
-  const devDeps = require('../package.json').devDependencies
-  const geckodriver = devDeps.geckodriver
+  const pluginDeps = require('../package.json').devDependencies
 
-  // chromedriver major version bumps every 6 weeks following Chrome
-  // so there may be a mismatch between
-  // user's installed browser version and the default provided version
-  // fallback to the devDependencies version in case detection fails
-  const chromedriver = installedBrowsers.chrome
-    ? installedBrowsers.chrome.match(/^(\d+)\./)[1]
-    : devDeps.chromedriver
+  if (webdrivers && webdrivers.includes('firefox')) {
+    devDependencies.geckodriver = pluginDeps.geckodriver
+  }
+  if (webdrivers && webdrivers.includes('chrome')) {
+    // chromedriver major version bumps every 6 weeks following Chrome
+    // so there may be a mismatch between
+    // user's installed browser version and the default provided version
+    // fallback to the devDependencies version in case detection fails
+    devDependencies.chromedriver = installedBrowsers.chrome
+      ? installedBrowsers.chrome.match(/^(\d+)\./)[1]
+      : pluginDeps.chromedriver
+  }
 
   api.extendPackage({
     scripts: {
       'test:e2e': 'vue-cli-service test:e2e'
     },
-    devDependencies: {
-      chromedriver,
-      geckodriver
-    }
+    devDependencies
   })
 }