[2.14.0] Async components don't get separate bundles

[danielroe]

Versions

• nuxt: v2.14.0
• node: v12.18.1

Reproduction

https://github.com/danielroe/webpack-async

Steps to reproduce

1. Clone repo
2. Run yarn build --analyze - note that there is a separate async bundle for the huge dependency twilio-video
3. Run yarn add nuxt@2.14 && yarn build --analyze - note that there is no separate async bundle

What is expected?

Bundle behaviour should not change in this significant of a way.

What is actually happening?

Significant performance degradation by bundling all dependencies in just five JS files (even on large sites), meaning we don't benefit from code-splitting or async dependencies.

Notes

• Regression introduced in b4ffdab

[pi0]

Seems issue is only happening when async chunk has one parent. Duplicating index to pages/foo results in correct behaviour:

[danielroe]

Hmm. I may need to improve the repro. I noticed the issue with an enterprise app where there is now only one vendors bundle with everything from node_modules used anywhere on any page throughout the app whereas before this was properly split into different page-related bundles.

[AndrewBogdanovTSS]

I can confirm this issue was introduced in 2.14.0
Same project
Nuxt 2.13.3: https://take.ms/T5Pzi
Nuxt 2.14.0: https://take.ms/pSk2W
@pi0 As you can see - builds are drastically different. Even if my async component has one parent - I still don't want all of such chunks to be put into one huge commons chunk. First of all - all of them are not related to each other, have different parent dependencies thus should be loaded separately. Secondly - even if async component have one parent - it still can be loaded/not loaded conditionally so it's still worth to be put it in a separate chunk. Long story short - it should still work as in 2.13.3

[pi0]

Should be fixed with v2.14.1

[AndrewBogdanovTSS]

@pi0 just checked it in v.2.14.1 - although the situation got better - there is still one regression left - I no longer have a separate bundle for vendors, everything is getting merged to app.js. Is it an intended change?
v. 2.13.3 https://take.ms/7dsh2
v. 2.14.1 https://take.ms/8P8Cv