next.js

b78f7d3f - Turbopack: order CSS modules by chunk-group co-occurrence in linearize (#95579)

Turbopack: order CSS modules by chunk-group co-occurrence in linearize (#95579) ## Summary The graph-based CSS chunker's `linearize` step produces the global module order that `split_into_chunks` then cuts into chunks. It previously broke ties between ready modules using a weight-sorted stack. It now prefers the ready module that shares the most chunk groups with the previously placed module, so modules that are loaded together end up adjacent in the global order and split into better-aligned chunks. On a real world example this measurably lowers the modeled chunk-loading cost, with fewer requests and less over-fetched CSS. The shared-group count is read from edge weights (how many chunk groups two modules co-occur in). Since `make_acyclic` deletes edges to break cycles, it now returns the edges it cut so `linearize` can still count those conflicting-order co-occurrences — reconstructing the full co-occurrence without cloning the graph. ## Verification - `cargo test -p turbopack-core style_groups_graph::tests` (all pass) - Validated on a real world example that the resulting global order is deterministic and the modeled chunk-loading cost decreases. <!-- NEXT_JS_LLM_PR -->