[ppr] RDC for RSCs (#79638)
This pull request introduces support for handling postponed state in
dynamic React Server Components (or RSC) requests, enabling the use of
the encoded Resume Data Cache (or RDC). The changes include adjustments
to the server logic to better manage dynamic responses and improve
caching behavior for such requests.
This also updates the incremental cache to also add to the RDC when it's
fetching already generated entries.
This pull request introduces changes to support dynamic React Server
Components (RSC) requests by enabling the use of postponed state and
improving cache handling. It also includes updates to error handling,
testing utilities, and incremental caching logic.
### Enhancements for Dynamic RSC Requests
* Added support for resuming renders with postponed data from the cache
for dynamic RSC requests, leveraging the `IncrementalCacheKind.APP_PAGE`
cache type. This ensures efficient reuse of cached data when available.
(`packages/next/src/server/base-server.ts`,
[[1]](diffhunk://#diff-6f4291cc2bfc5073fdca12a014011769e840ee68583db1468acef075f037015aL3097-R3139)
[[2]](diffhunk://#diff-6f4291cc2bfc5073fdca12a014011769e840ee68583db1468acef075f037015aL3262-R3294)
* Updated cache control logic to handle dynamic RSC requests more
effectively, ensuring they are not cached when containing dynamic
content. (`packages/next/src/server/base-server.ts`,
[packages/next/src/server/base-server.tsL3526-R3550](diffhunk://#diff-6f4291cc2bfc5073fdca12a014011769e840ee68583db1468acef075f037015aL3526-R3550))
### Improvements to Incremental Caching
* Introduced a `checkTags` method in the `IncrementalCache` class to
determine if a tag has been revalidated, preventing stale data from
being returned.
(`packages/next/src/server/lib/incremental-cache/index.ts`,
[packages/next/src/server/lib/incremental-cache/index.tsR599-R627](diffhunk://#diff-c990316f5df4319261936cd61b07566c5e12cd7e68c9e92f6da38a190a639154R599-R627))
* Refactored logic to store prerender resume data in the cache for
better performance and reliability.
(`packages/next/src/server/lib/incremental-cache/index.ts`,
[packages/next/src/server/lib/incremental-cache/index.tsL442-R461](diffhunk://#diff-c990316f5df4319261936cd61b07566c5e12cd7e68c9e92f6da38a190a639154L442-R461))
### Testing Updates
* Updated E2E tests in `app-action.test.ts` to use modern `fs/promises`
and `node:path` modules, improving readability and consistency.
(`test/e2e/app-dir/actions/app-action.test.ts`,
[test/e2e/app-dir/actions/app-action.test.tsL11-R14](diffhunk://#diff-b3bc78ed83df32c7d5afa3d352038f8afd7eb37027be87ca22bac3d3cb33657aL11-R14))
* Refactored test assertions to ensure dynamic RSC behavior and
revalidation logic are correctly validated.
(`test/e2e/app-dir/actions/app-action.test.ts`,
[[1]](diffhunk://#diff-b3bc78ed83df32c7d5afa3d352038f8afd7eb37027be87ca22bac3d3cb33657aR543-L546)
[[2]](diffhunk://#diff-b3bc78ed83df32c7d5afa3d352038f8afd7eb37027be87ca22bac3d3cb33657aL1564-R1589)
