Production build with directories marked with `isAsync: false` imports components asynchronously

[gtnsimon]

Describe the bug

Components imported using nuxt/components with isAsync option set to false are imported asynchronously when building for production using nuxt build.

To Reproduce
Steps to reproduce the behavior:

1. Clone repository https://github.com/gtnsimon/codesandbox-nuxt
2. Go to the branch bug/non-async-components
3. Run yarn then yarn run build
4. Open generated file .nuxt/components/index.js
   First line is:

export const Tutorial = () => import('../../components/Tutorial.vue' /* webpackChunkName: "components/tutorial" */).then(c => wrapFunctional(c.default || c))

Expected behavior

Generated file .nuxt/components/index.js should import components synchronously.

In development when we run Nuxt using yarn run dev the first line is a synchronous import which is expected as directory options explicitly set isAsync: false:

export { default as Tutorial } from '../../components/Tutorial.vue'

Additional context

I'm running nuxt v2.15.8 which embeds @nuxt/components v2.1.8 and above (v2.2.1 when I check installed node_modules).

While trying to debug I found code which may cause the issue:

• components/src/scan.ts

  Line 42 in 86ab5e0

  const isAsync = (fileName.endsWith('.async') ? true : dirIsAsync) || null

  
  Ternary operator will always fallback to null when file doesn't contains .async and dirIsAsync is not true. Settings false will be replaced to null.

• components/templates/components/index.js

  Line 7 in 86ab5e0

  if (c.isAsync === true || (!isDev /* prod fallback */ && c.isAsync === null)) {

  
  This condition is met because I'm running a production build and isAsync is now null because replaced by the above code so it use the asyncImport syntax defined.

• allow setting directory isAsync = false in options #239
  seems to address the issue but I don't know about changing null to true.

My nuxt.config.js

export default {
 /* ... */
 // Auto import components: https://go.nuxtjs.dev/config-components
 components: [ { path: '~/components', isAsync: false } ], // custom options with `isAsync: false`

 /* ... */
}

Merci 😊

[hipop]

This problem still exists (22/07/2022)

components/src/scan.ts

Line 42 in 86ab5e0

const isAsync = (fileName.endsWith('.async') ? true : dirIsAsync) || null

I used string type to bypass this bug

export default {
 /* ... */
 // Auto import components: https://go.nuxtjs.dev/config-components
 components: [ { path: '~/components', isAsync: 'false' } ], // custom options with `isAsync: false`

 /* ... */
}

[TerkaPrzemyslaw1897]

This is still the case, after almost 2 years one of the core functionality of this plugin still doesn't work...
I spent almost 8 hours to figure out why parent components mount earlier than child components, and now I find out that I have to stop using this plugin because of this bug 😭