Currently we error if you cannot produce a shell unless you have a
Suspense boundary above the root. This is fine for normal IO but sync IO
like Math.random() and new Date() have much more significant bad
consequences for prerendering. Instead of treating these errors as
another flavor of "must have a shell" validation we should instead treat
them like they must be guarded behind something else dynamic like `await
connection()`.
In addition to unconditionally erroring for Sync IO in Server Components
when prerendering this change also removes the Sync IO warning for
runtime prefetches. This is because at the moment there is no way to
debug these errors in dev. In the future we will add validation for
prefetches and need to add back in some ability to warn for these cases
but until then we will leave this case as a silent deopt.
## What?
Rename `experimental.dynamicIO` to `experimental.cacheComponents` across
the Next.js codebase.
## Why?
We're going to be merging the functionality of the `ppr`, `dynamicIO`
and `useCache` experimental flags into the singular `cacheComponents`
flag to reduce complexity of the codebase and simplify adoption for
users wanting to experiment with experimental features.
## How?
- Renamed the configuration option from `experimental.dynamicIO` to
`experimental.cacheComponents`
- Added deprecation handling with automatic migration for the old option
name
- Updated all documentation, tests, and internal references
- Updated Rust code in SWC transforms and Turbopack
- Maintained backward compatibility with deprecation warnings
NAR-158
Josh Story