Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Improve Server Actions compiler #58391

Merged
merged 7 commits into from
Nov 21, 2023
Merged

Improve Server Actions compiler #58391

merged 7 commits into from
Nov 21, 2023

Conversation

shuding
Copy link
Member

@shuding shuding commented Nov 13, 2023

Currently to make inline-defined Server Actions work, the compiler hoists the actual "use server" function to the module level and convert the inlined function to a parentheses expression that creates a noop wrapper function and wraps it with the proxy. This works fine however expressions are still different from declarations (#57392). So there're some details that can't be aligned well.

With this change, we're going to make the compilation for the two types of inline-defined Server Actions more robust and more lightweight:

1. Expressions

const action = async () => { "use server" ... }
const action = async function () { "use server" ... }
const action = async function named () { "use server" ... }
foo={async function () { "use server" ... }}
...

These expressions can directly be replaced with a new expression createActionProxy("id", hoisted_action). A .bind(...) member call can be followed if it needs to bind any variables from the closure level.

2. Declarations

async function named () { "use server" ... }

In this case, we replace all the same named idents to be the expression createActionProxy("id", hoisted_action), and removed that function declaration.

With these changes, these will be fewer structural changes to the AST and the code is more performant.

The PR also changes it to use React's registerServerReference method directly instead of our in-house implementation inside createActionProxy.

Another small change is to stabilize the comment header to use BTreeMap inside the SWC transform. Otherwise the test snapshots will randomly mismatch.

Closes #57392.

@ijjk ijjk added created-by: Next.js team PRs by the Next.js team. type: next labels Nov 13, 2023
@ijjk
Copy link
Member

ijjk commented Nov 13, 2023

Tests Passed

@ijjk
Copy link
Member

ijjk commented Nov 13, 2023

Stats from current PR

Default Build
General
vercel/next.js canary vercel/next.js shu/a4c8 Change
buildDuration 10.7s 10.5s N/A
buildDurationCached 5.9s 6.5s ⚠️ +620ms
nodeModulesSize 199 MB 199 MB N/A
nextStartRea..uration (ms) 413ms 423ms N/A
Client Bundles (main, webpack)
vercel/next.js canary vercel/next.js shu/a4c8 Change
199-HASH.js gzip 28.7 kB 28.7 kB N/A
3f784ff6-HASH.js gzip 53.3 kB 53.3 kB
494.HASH.js gzip 180 B 181 B N/A
framework-HASH.js gzip 45.2 kB 45.2 kB
main-app-HASH.js gzip 241 B 240 B N/A
main-HASH.js gzip 31.7 kB 31.7 kB N/A
webpack-HASH.js gzip 1.7 kB 1.7 kB
Overall change 100 kB 100 kB
Legacy Client Bundles (polyfills)
vercel/next.js canary vercel/next.js shu/a4c8 Change
polyfills-HASH.js gzip 31 kB 31 kB
Overall change 31 kB 31 kB
Client Pages
vercel/next.js canary vercel/next.js shu/a4c8 Change
_app-HASH.js gzip 194 B 195 B N/A
_error-HASH.js gzip 182 B 181 B N/A
amp-HASH.js gzip 501 B 503 B N/A
css-HASH.js gzip 322 B 323 B N/A
dynamic-HASH.js gzip 2.5 kB 2.5 kB
edge-ssr-HASH.js gzip 253 B 255 B N/A
head-HASH.js gzip 348 B 347 B N/A
hooks-HASH.js gzip 369 B 368 B N/A
image-HASH.js gzip 4.28 kB 4.27 kB N/A
index-HASH.js gzip 256 B 256 B
link-HASH.js gzip 2.61 kB 2.6 kB N/A
routerDirect..HASH.js gzip 311 B 311 B
script-HASH.js gzip 384 B 383 B N/A
withRouter-HASH.js gzip 307 B 308 B N/A
1afbb74e6ecf..834.css gzip 106 B 106 B
Overall change 3.17 kB 3.17 kB
Client Build Manifests
vercel/next.js canary vercel/next.js shu/a4c8 Change
_buildManifest.js gzip 484 B 483 B N/A
Overall change 0 B 0 B
Rendered Page Sizes
vercel/next.js canary vercel/next.js shu/a4c8 Change
index.html gzip 528 B 526 B N/A
link.html gzip 538 B 540 B N/A
withRouter.html gzip 522 B 522 B
Overall change 522 B 522 B
Edge SSR bundle Size
vercel/next.js canary vercel/next.js shu/a4c8 Change
edge-ssr.js gzip 92.4 kB 92.4 kB N/A
page.js gzip 145 kB 145 kB N/A
Overall change 0 B 0 B
Middleware size
vercel/next.js canary vercel/next.js shu/a4c8 Change
middleware-b..fest.js gzip 624 B 624 B
middleware-r..fest.js gzip 150 B 151 B N/A
middleware.js gzip 24.8 kB 24.8 kB N/A
edge-runtime..pack.js gzip 1.92 kB 1.92 kB
Overall change 2.55 kB 2.55 kB
Next Runtimes
vercel/next.js canary vercel/next.js shu/a4c8 Change
app-page-exp...dev.js gzip 167 kB 167 kB
app-page-exp..prod.js gzip 93.4 kB 93.4 kB
app-page-tur..prod.js gzip 94.1 kB 94.1 kB
app-page-tur..prod.js gzip 88.7 kB 88.7 kB
app-page.run...dev.js gzip 137 kB 137 kB
app-page.run..prod.js gzip 88 kB 88 kB
app-route-ex...dev.js gzip 23.8 kB 23.8 kB
app-route-ex..prod.js gzip 16.4 kB 16.4 kB
app-route-tu..prod.js gzip 16.5 kB 16.5 kB
app-route-tu..prod.js gzip 16 kB 16 kB
app-route.ru...dev.js gzip 23.2 kB 23.2 kB
app-route.ru..prod.js gzip 16 kB 16 kB
pages-api-tu..prod.js gzip 9.37 kB 9.37 kB
pages-api.ru...dev.js gzip 9.64 kB 9.64 kB
pages-api.ru..prod.js gzip 9.37 kB 9.37 kB
pages-turbo...prod.js gzip 21.8 kB 21.8 kB
pages.runtim...dev.js gzip 22.5 kB 22.5 kB
pages.runtim..prod.js gzip 21.8 kB 21.8 kB
server.runti..prod.js gzip 49.1 kB 49.1 kB
Overall change 924 kB 924 kB
Commit: 81feb36

@shuding shuding marked this pull request as ready for review November 20, 2023 15:55
@shuding shuding requested a review from kdy1 November 21, 2023 06:28
@kodiakhq kodiakhq bot merged commit 9471fb8 into canary Nov 21, 2023
@kodiakhq kodiakhq bot deleted the shu/a4c8 branch November 21, 2023 13:35
}

// In this example, if Button immediately executes the action, different ids should
// be passed.
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

However if Button does not immediately execute the action then the same (double-incremented) id should be passed for both, which doesn't seem to be handled correctly with this compilation.

In addition, I believe we don't even let you run server actions at render time so I'm not sure it makes sense to optimize for that case?

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Another option might be to forbid capturing any mutable bindings and add a constraint that any captured variables must be assigned before the closure is referenced? Best practice is to have no interior mutability anywhere within props and arguably a captured let that gets reassigned is a type of mutability.

But I would argue the current compilation here is incorrect.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yeah I later realized that we should just disallow mutating any captured variables, as it's impossible to pass any mutability across the boundary.

@github-actions github-actions bot added the locked label Dec 8, 2023
@github-actions github-actions bot locked as resolved and limited conversation to collaborators Dec 8, 2023
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Projects
None yet
Development

Successfully merging this pull request may close these issues.

Server actions doesn't work with hoisted function declarations
5 participants