Async components files are not returned in preloadFiles

[juvirez]

If a component is defined as an async component like this:

app.component('HelloWorld', defineAsyncComponent(() => import(/* webpackChunkName: "hello-world" */ './components/HelloWorld.vue')));

Component resources (js, css) are not included in the result of renderToString().preloadFiles().

Here is example: https://github.com/juvirez/test-async-components

• async component definition
• renderToString call

It looks like here is the code responsible for this:

vue-bundle-renderer/src/renderer.ts

Lines 160 to 166 in d01cf4e

	export function getUsedAsyncFiles (ssrContext: SSRContext, renderContext: RenderContext): Array<Resource> {
	if (!ssrContext._mappedFiles && ssrContext._registeredComponents && renderContext.mapFiles) {
	const registered = Array.from(ssrContext._registeredComponents)
	ssrContext._mappedFiles = renderContext.mapFiles(registered).map(normalizeFile)
	}
	return ssrContext._mappedFiles || []
	}

But in my case _registeredComponents is undefined. How can I define this variable for ssrContext?

[danielroe]

If you're using webpack, _registeredComponents needs to be filled out with all components used to render a page. Previously vue-loader did this in v15 and it's still planned for v16: vuejs/vue-loader#1887

Here's how we do it in Nuxt for webpack: https://github.com/nuxt/framework/blob/4712e994112a97feba447b3edb4afb65e968ed63/packages/nuxt/src/app/plugins/preload.server.ts#L1-L12

[dmitryuk]

@danielroe do you know where __moduleIdentifier param is set? It is missing in my case
nuxt/nuxt#29747