[Feature]: Upgrade default browser target

[vegerot]

What problem does this feature solve?

Continued from web-infra-dev/rspack#10290

What does the proposed API look like?

The main issue is that this will be a breaking change, so this should wait until the next major release. According to @chenjiahan the next breaking change will be Q3 2025 when we upgrade the minimum-supported Node version from v16. I propose we include the default browser target upgrade in that release too.

[vegerot]

💡 idea: to improve the performance of dev builds even more, we can entirely disable transpiling for dev builds.

• Pros:
  • Faster build time
  • Devs will almost always be using the latest version of their browser
• Cons:
  • Differences in dev and prod builds

[chenjiahan]

we can entirely disable transpiling for dev builds.

Thanks for your suggestion. We value the consistency between dev and build, and disabling SWC transpiling in dev does not bring enough performance gains, so we do not plan to introduce this change

[chenjiahan]

I would like to clarify that, at present, we are only considering dropping support for Node.js 16 in Q3 2025. We have no plans to introduce other breaking changes in minor releases. Any other breaking changes will have to wait until Rsbuild 2.0 is released next year.