fix(prefetch-sw): only prefetch direct imports

[wmertens]

• use prefetch sw with docs

It was adding dynamic imports, which is not correct. Those should be handled by Link prefetching and Insights.

Furthermore, the graph is reduced by not including dependencies that other dependencies already import.

[changeset-bot]

🦋 Changeset detected

Latest commit: da895f6

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@builder.io/qwik	Patch
eslint-plugin-qwik	Patch
@builder.io/qwik-city	Patch
create-qwik	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

Open in Stackblitz

npm i https://pkg.pr.new/@builder.io/qwik@6853

npm i https://pkg.pr.new/@builder.io/qwik-city@6853

npm i https://pkg.pr.new/eslint-plugin-qwik@6853

npm i https://pkg.pr.new/create-qwik@6853

commit: da895f6

[github-actions]

built with Refined Cloudflare Pages Action

⚡ Cloudflare Pages Deployment

Name	Status	Preview	Last Commit
qwik-docs	✅ Ready (View Log)	Visit Preview	da895f6

[mhevery]

I don't think removing dynamic import is the right fix here. It is true that we are currently over fetching do to dynamic imports, but I think better fix is to encode which imports are dynamic into the graph (for example negative numbers are dynamic imports)

SW can than make decisions on this.

Also it would be great if we could differentiate dynamic import form useTask (which will very likely be needed) from a route navigation, which is much less likely to be needed.

This is why I think the fix here is to encode more information so that SW can make more intelligent decisions.

In the past we ran into issues where SW would fetch static imports but not dynamic and than the site was slow because the initial click handler would get processed but subsequent useTask etc... would be slow.

[wmertens]

@mhevery We can differentiate imports, handlers, segments, and dynamic imports. We can differentiate by negative numbers indicating the type of what follows, -1 handlers, -2 segments, -3 dynamic.

Alternatively, Qwik loader can just tell us which handlers are actually on the page and those then get fetched opportunistically, no differentiation needed, only direct imports. What do you think?

🤔 Or indeed any dynamically imported segments that are not handlers are likely to be tasks etc.

Ah and we can sort by module size, should we fetch big or small modules first?

Not for this PR, but the prefetch SW is also missing:

• limit concurrent downloads
• clear speculative fetches on navigation
• a way for qwik city to declare a path-to-imports mapping for link prefetching. I'm thinking qwik-city extends the manifest with paths and their imports.
• support for insights

[wmertens]

@mhevery I now detect tasks (by the fact that they also export _hW) and fetch them with lower priority. Other dynamic imports are left up to the qprefetch events.

WDYT?

[mhevery]

My understanding is that you and Shai had a chat and decided to add this as a temporary work around, and than fix it later. In that case this is good to go.