Prompts.js with a function doesn't work when using a plugin in a preset

[deraw]

Version

4.1.2

Environment info

Environment Info:

  System:
    OS: Linux 4.15 Ubuntu 18.04.3 LTS (Bionic Beaver)
    CPU: (8) x64 Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
  Binaries:
    Node: 12.13.1 - /usr/local/bin/node
    Yarn: 1.21.1 - /usr/bin/yarn
    npm: 6.13.4 - /usr/local/bin/npm
  Browsers:
    Chrome: 79.0.3945.130
    Firefox: 72.0.2
  npmGlobalPackages:
    @vue/cli: 4.1.2

Steps to reproduce

Create a plugin with a prompt.js file that exports a function, eg:

// prompts.js

// pass `package.json` of project to function argument
module.exports = pkg => {
  const prompts = [
    {
      type: 'input',
      name: 'locale',
      message: 'The locale of project localization.',
      validate: input => !!input,
      default: 'en'
    }
  ]

  // add dynamically prompt
  if ('@vue/cli-plugin-eslint' in (pkg.devDependencies || {})) {
    prompts.push({
      type: 'confirm',
      name: 'useESLintPluginVueI18n',
      message: 'Use ESLint plugin for Vue I18n ?'
    })
  }

  return prompts
}

(from the docs https://cli.vuejs.org/dev-guide/plugin-dev.html#prompts)

Use that plugin in a preset and try to create a project using it

What is expected?

The function is called without error

What is actually happening?

This error occurs:

 ERROR  TypeError: obs.pipe is not a function
TypeError: obs.pipe is not a function
    at PromptUI.run (/usr/local/lib/node_modules/@vue/cli/node_modules/inquirer/lib/ui/prompt.js:33:24)
    at Object.promptModule [as prompt] (/usr/local/lib/node_modules/@vue/cli/node_modules/inquirer/lib/inquirer.js:28:22)
    at Creator.resolvePlugins (/usr/local/lib/node_modules/@vue/cli/lib/Creator.js:382:36)
    at Creator.create (/usr/local/lib/node_modules/@vue/cli/lib/Creator.js:196:32)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at async create (/usr/local/lib/node_modules/@vue/cli/lib/create.js:72:3)

---

I think it's because there is no check on prompts type on this line https://github.com/vuejs/vue-cli/blob/dev/packages/%40vue/cli/lib/Creator.js#L384