Rspack 1.4 Release Plan

[h-a-n-a]

Rspack 1.4 is estimated to be released in the middle of June, 2025.

Features

1. SWC upgrade

PR #10660
Author @GiveMe-A-Name

2. New CssChunkingPlugin

Issue #10235
Author @SyMind

3. Lazy compilation supports multiCompiler

PR #9828
Author @JSerFeng

4. WASM target

Issue #4550
Author @CPunisher

5. Support inputFileSystem

PR #8643
Author @nilptr @stormslowly

6. Deprecate experiments.parallelCodeSplitting

Issue #9059
Author @JSerFeng

Performance

1. Enable experiments.incremental by default

experiments.incremental config will be enabled by default in 1.4.0 to speed up HMR.

Author @ahabhgk

Bug fixes

TODO

Chore

1. Upgrade zod to v4

#10467

Author @colinaaa

Tasks

TODO

[markmssd]

In our project (big one), parallelCodeSitting was slowing startup and HMR time quite lot, and we disabled it when upgrading to 1.3. It might be because of our code splitting configuration, not sure yet. I'll try to do a repro.

[n0th1ng-else]

Thank you for the headsup! indeed there are a couple of things that we are suffering from while I am trying to update the version. and turns out parallelCodeSitting is one of them

[JSerFeng]

Did you disable optimization.removeAvailableModules?

You can set stats.logging = 'verbose', then check the time cost for rebuild chunk graph

[h-a-n-a]

Oh here's someone else experiencing this: #8976 (comment)! (@n0th1ng-else)

We've been working on this. Just stay tuned for future updates ;-).

[JSerFeng]

For parallelCodeSplitting, we better create a separate issue, are you available to make one with repro or more detail info? It would be very helpful❤️ @markmssd @n0th1ng-else

[n0th1ng-else]

Thank you. took it separatelly

[dingff]

Will version 1.4 be released this week?

[chenjiahan]

We have just released v1.4.0-rc.0 and we plan to release v1.4.0 stable this week.