next.js

47ad350d - [turbopack] Sort modules in chunks to reduce duplicates (#94961)

[turbopack] Sort modules in chunks to reduce duplicates (#94961) # What When building a chunk, lay out chunk_items in sorted order. # Why There are a number of ways turbopack can create chunk groups with identical sets of chunk items, but different chunk parents or different availability info. This means we cannot trivially deduplicate these chunks. Heuristics inside of `make_production_chunks` means we also do not always observe 'trivial merge opportunities' there either. By canonically sorting these chunks we can ensure that we produce the same content and thus select the same filenames. See https://vercel.slack.com/archives/C09R44U5HQW/p1781814781879439, on https://vercel.com/academy when switching to Turbopack, we started shipping duplicate chunks that only differed by order. Now, module ordering is fixed in chunks so that the file name hashes are consistent and we don't ship duplicates. For vercel-academy, before: | | Client JS | Client CSS | Client Source Maps | Server Bundled JS | Server Unbundled | Server Source Maps | | --------- | ------------------ | ------------------- | ------------------ | -------------------- | --------------------- | -------------------- | | **Total** | 41 files / 7.24 MB | 5 files / 580.57 KB | - | 286 files / 18.30 MB | 1700 files / 48.26 MB | 286 files / 78.63 MB |[4:54 PM]to:[4:54 PM]## Totals after: | | Client JS | Client CSS | Client Source Maps | Server Bundled JS | Server Unbundled | Server Source Maps | | --------- | ------------------ | ------------------- | ------------------ | -------------------- | --------------------- | -------------------- | | **Total** | 36 files / 4.43 MB | 5 files / 580.57 KB | - | 286 files / 18.30 MB | 1700 files / 48.26 MB | 286 files / 78.63 MB |