## [1.0.0-rc.5] - 2026-02-18

💡 Smarter `entriesAware` Manual Code Splitting                                                                 
                                             
New `entriesAware` and `entriesAwareMergeThreshold` options for `manualCodeSplitting.groups[]` enable              
entry-reachability-based chunk splitting with automatic small chunk merging.                                       
                                                                                                                   
- `entriesAware: true` splits matched modules by entry reachability — modules reached by the same set of entries are grouped together, providing the most precise loading behavior with less over-fetching
- Chunks now get more readable names reflecting their entry associations (e.g. `vendor-entry-a-entry-b.js`) instead of opaque hashes
- `entriesAwareMergeThreshold` sets a byte-size threshold to merge tiny subgroups into the closest sibling with the fewest extra entries, reducing micro-chunk fragmentation while preserving precision
- Recommended to use together with `maxSize`: merge tiny chunks first to reduce request overhead, then cap large chunks to control payload size

```js
manualCodeSplitting: {
  groups: [{
    name: 'vendor',
    test: /node_modules/,
    entriesAware: true,
    entriesAwareMergeThreshold: 28000, // bytes
  }]
}
```

### 🚀 Features

- add `Visitor` to `rolldown/utils` (#8373) by @sapphi-red
- module-info: add `inputFormat` property to `ModuleInfo` (#8329) by @shulaoda
- default `treeshake.invalid_import_side_effects` to `false` (#8357) by @sapphi-red
- rolldown_utils: add `IndexBitSet` (#8343) by @sapphi-red
- rolldown_utils: add more methods and trait impls to BitSet (#8342) by @sapphi-red
- rolldown_plugin_vite_build_import_analysis: add support for `await import().then((m) => m.prop)` (#8328) by @sapphi-red
- rolldown_plugin_vite_reporter: support custom logger for build infos (#7652) by @shulaoda
- rust/mcs: support `entriesAwareMergeThreshold` (#8312) by @hyf0
- mcs: `maxSize` will split the oversized chunk with taking file relevance into account (#8277) by @hyf0
- rolldown_plugin_vite_import_glob: support template literal in glob import patterns (#8298) by @shulaoda
- rolldown_plugin_chunk_import_map: output importmap without spaces (#8297) by @sapphi-red
- add INEFFECTIVE_DYNAMIC_IMPORT warning in core (#8284) by @shulaoda
- mcs: generate more readable name for `entriesAware` chunks (#8275) by @hyf0
- mcs: support `entriesAware` (#8274) by @hyf0

### 🐛 Bug Fixes

- improve circular dependency detection in chunk optimizer (#8371) by @IWANABETHATGUY
- align `minify.compress: true` and `minify.mangle: true` with `minify: true` (#8367) by @sapphi-red
- rolldown_plugin_esm_external_require: apply conversion to UMD and IIFE outputs (#8359) by @sapphi-red
- cjs: bailout treeshaking on cjs modules that have multiple re-exports (#8348) by @hyf0
- handle member expression and this expression in JSX element name rewriting (#8323) by @IWANABETHATGUY
- pad `encode_hash_with_base` output to fixed length to prevent slice panics (#8320) by @shulaoda
- `xxhash_with_base` skips hashing when input is exactly 16 bytes (#8319) by @shulaoda
- complete `ImportKind::try_from` with missing variants and correct `url-import` to `url-token` (#8310) by @shulaoda
- mark Node.js builtin modules as side-effect-free when resolved via `external` config (#8304) by @IWANABETHATGUY
- mcs: `maxSize` should split chunks correctly based on sizes (#8289) by @hyf0

### 🚜 Refactor

- introduce `RawMangleOptions` and `RawCompressOptions` (#8366) by @sapphi-red
- mcs: refactor `apply_manual_code_splitting` into `ManualSplitter` (#8346) by @hyf0
- rolldown_plugin_vite_reporter: simplify hook registration and remove redundant state (#8322) by @shulaoda
- use set to store user defined entry modules (#8315) by @IWANABETHATGUY
- rust/mcs: collect groups into map at first for having clean and performant operations (#8313) by @hyf0
- mcs: introduce newtype `ModuleGroupOrigin` and `ModuleGroupId` (#8311) by @hyf0
- remove unnecessary `FinalizerMutableState` struct (#8303) by @shulaoda
- move module finalization into `finalize_modules` (#8302) by @shulaoda
- extract `apply_transfer_parts_mutation` into its own module (#8301) by @shulaoda
- move ESM format check into `determine_export_mode` (#8294) by @shulaoda
- remove `warnings` field from `GenerateContext` (#8293) by @shulaoda
- extract util function remove clippy supression (#8290) by @IWANABETHATGUY
- move `is_in_node_modules` to `PathExt` trait in `rolldown_std_utils` (#8286) by @shulaoda
- rolldown_plugin_vite_reporter: remove unnecessary ineffective dynamic import detection logic (#8285) by @shulaoda
- dev: inject hmr runtime to `\0rolldown/runtime.js` (#8234) by @hyf0
- improve naming in chunk_optimizer (#8287) by @IWANABETHATGUY
- simplify PostChunkOptimizationOperation from bitflags to enum (#8283) by @IWANABETHATGUY
- optimize BitSet.index_of_one to return iterator instead of Vec (#8282) by @IWANABETHATGUY

### 📚 Documentation

- change default value in `format` JSDoc from `'esm'` to `'es'` (#8372) by @shulaoda
- in-depth: remove `invalidImportSideEffects` option mention from lazy barrel optimization doc (#8355) by @sapphi-red
- mcs: clarify `minSize` constraints (#8279) by @ShroXd

### ⚡ Performance

- use IndexVec for chunk TLA detection (#8341) by @sapphi-red
- only invoke single resolve call for the same specifier and import kind (#8332) by @sapphi-red
- rolldown_plugin_vite_reporter: skip gzip computation when `report_compressed_size` is disabled (#8321) by @shulaoda

### 🧪 Testing

- use `vi.waitFor` and `expect.poll` instead of custom `waitUtil` function (#8369) by @sapphi-red
- rolldown_plugin_esm_external_require_plugin: add tests (#8358) by @sapphi-red
- add watch file tests (#8330) by @sapphi-red
- rolldown_plugin_vite_build_import_analysis: add test for dynamic import treeshaking (#8327) by @sapphi-red

### ⚙️ Miscellaneous Tasks

- prepare-release: skip workflow on forked repositories (#8368) by @shulaoda
- format more files (#8360) by @sapphi-red
- deps: update oxc to v0.114.0 (#8347) by @camc314
- deps: update test262 submodule for tests (#8354) by @sapphi-red
- deps: update crate-ci/typos action to v1.43.5 (#8350) by @renovate[bot]
- deps: update oxc apps (#8351) by @renovate[bot]
- rolldown_plugin_vite_reporter: remove unnecessary README.md (#8334) by @shulaoda
- deps: update npm packages (#8338) by @renovate[bot]
- deps: update rust crates (#8339) by @renovate[bot]
- deps: update dependency oxlint-tsgolint to v0.13.0 (#8337) by @renovate[bot]
- deps: update github-actions (#8336) by @renovate[bot]
- deps: update napi to v3.8.3 (#8331) by @renovate[bot]
- deps: update dependency oxlint-tsgolint to v0.12.2 (#8325) by @renovate[bot]
- remove unnecessary transform.decorator (#8314) by @IWANABETHATGUY
- deps: update dependency rust to v1.93.1 (#8305) by @renovate[bot]
- deps: update dependency oxlint-tsgolint to v0.12.1 (#8300) by @renovate[bot]
- deps: update oxc apps (#8296) by @renovate[bot]
- docs: don't skip for build runs without cache (#8281) by @sapphi-red

…mizer

The circular dependency check added by rolldown#8371 was correct for chunks
containing the runtime module or runtime-dependent modules (e.g.,
__commonJSMin, __toESM), but overly conservative for regular ESM chunks.

ESM handles circular imports fine — modules are initialized lazily and
circular references are resolved at access time. Only runtime helpers
need to be available synchronously before the importing module executes,
making circular chunk imports harmful only when runtime is involved.

This fix scopes the circular dependency check to only apply when the
source chunk contains:
1. The runtime module itself, OR
2. Modules that depend on runtime helpers (depended_runtime_helper)

For all other pure ESM chunks, the merge is allowed regardless of
whether it would create circular chunk imports.

In large applications, this was causing +53% more JS files and +8%
bundle size because the cycle detection blocked almost all common
chunk merges.

Closes rolldown#8371 regression
Refs: rolldown#8361, rolldown#8886, rolldown#8910, rolldown#8915

…tection (#9049)

## Summary

PR #8371 improved circular dependency detection in the chunk optimizer
to fix #8361 (`__commonJSMin is not a function`). However, the fix
introduced an over-approximation that blocks many legitimate chunk
merges, causing a significant regression in bundle size and file count.

Fixes #9093

## Problem

The current algorithm in `would_create_circular_dependency` does a BFS
from `source.deps ∪ target.deps` and simulates post-merge edges for
**every** chunk that depends on source. This causes false positives
because:

1. Starting BFS from `target.deps` means target can trivially "reach
itself" through any transitive dependency that also depends on source
2. The post-merge edge simulation amplifies this by redirecting any
source-dependent chunk back to target

In a large application with ~2,200 entry points, this blocks **1,046
legitimate merges**, producing **+1,224 extra chunks** and **+8% bundle
size**.

## Fix

Split the algorithm into two cases based on whether source has
dependencies:

- **Source has deps**: Only BFS from `source.deps` without post-merge
simulation. This is sufficient because if target is reachable from
source's dependency tree, merging would create a real cycle.

- **Source has no deps** (e.g., runtime chunk): Keep the full algorithm
with `target.deps` BFS and post-merge simulation. This correctly detects
cycles like `target → chunk_A → source(=target after merge)`, which is
the pattern from #8361.

## Results

Tested on a large application (~2,200 entry points):

| Metric | Before (rc.9) | After (this fix) | Improvement |
|--------|--------------|-------------------|-------------|
| JS files | 3,212 | 2,418 | **-794 (-25%)** |
| JS size | 73.13 MB | 63.99 MB | **-9.14 MB (-12.5%)** |

## Testing

- ✅ `#8361` and `#8361_2` integration tests pass (the bug this algorithm
was designed to fix)
- ✅ Full integration test suite: **1,652 passed**, 0 failed (1 skipped
due to missing test262 submodule)
- ✅ New regression test added (`#9049`)
- ✅ Verified on large production application

Fixes vitejs/vite#22007

---------

Co-authored-by: Alon Mizrahi <almizrahi@paloaltonetworks.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: IWANABETHATGUY <iwanabethatguy@qq.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>