# rolldown v1.2.6

- Product: rolldown (https://whatsnew.fyi/product/rolldown)
- Vendor: rolldown
- Date: 2026-08-26
- Version: v1.2.6
- Original notes: https://github.com/rolldown/rolldown/releases/tag/v1.2.6
- Permalink: https://whatsnew.fyi/product/rolldown/releases/v1.2.6

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Support property name mangling in minify
- **added** — Add `tsconfig: string` option to `transform`
- **added** — Add `tsconfig` option to rolldown_plugin_vite_transform
- **added** — Add top-level `tsconfig` option to rolldown_plugin_vite_resolve
- **added** — Expose module graph queries on the dev engine handle
- **fixed** — Assign import bindings before initializing dependencies in dev
- **fixed** — Copy star re-exports before initializing dependencies in dev
- **fixed** — Register an empty exports object for a module without exports in dev
- **fixed** — Name the module when a `codeSplitting` group callback returns a wrong type
- **fixed** — Map dev rename events like build watch
- **fixed** — Clear resolution cache when `TsconfigCache::clear` is called
- **fixed** — Resolve in-flight `ensureLatestBuildOutput` when the engine closes in dev
- **fixed** — Replace undeclared BindingErrorsOr with BindingResult in hook types in binding
- **changed** — Collapse fs-watcher backends behind a single FsWatcher in rolldown_fs_watcher
- **changed** — Batch `codeSplitting` group `test` / `name` calls for performance
- **changed** — Enable compiler cache via `module.enableCompileCache()`
- **changed** — Upgrade oxc to 0.147.0

##### [1.2.6] - 2026-08-26

###### 🚀 Features

- minify: support property name mangling (#10374) by @Dunqing
- add `tsconfig: string` option to `transform` (#10727) by @sapphi-red
- rolldown_plugin_vite_transform: add `tsconfig` option (#10725) by @sapphi-red
- rolldown_plugin_vite_resolve: add top-level `tsconfig` option (#10724) by @sapphi-red
- dev: expose module graph queries on the dev engine handle (#10716) by @h-a-n-a

###### 🐛 Bug Fixes

- dev: assign import bindings before initializing dependencies (#10783) by @h-a-n-a
- dev: copy star re-exports before initializing dependencies (#10761) by @h-a-n-a
- dev: register an empty exports object for a module without exports (#10772) by @h-a-n-a
- name the module when a `codeSplitting` group callback returns a wrong type (#10753) by @IWANABETHATGUY
- dev: map dev rename events like build watch (#10758) by @shulaoda
- clear resolution cache when `TsconfigCache::clear` is called (#10726) by @sapphi-red
- dev: resolve in-flight `ensureLatestBuildOutput` when the engine closes (#10730) by @h-a-n-a
- binding: replace undeclared BindingErrorsOr with BindingResult in hook types (#10717) by @h-a-n-a

###### 🚜 Refactor

- rolldown_fs_watcher: collapse fs-watcher backends behind a single FsWatcher (#10735) by @shulaoda
- hoist invariants out of the `codeSplitting` group loop (#10744) by @IWANABETHATGUY

###### 📚 Documentation

- document shared notify rename mapping (#10759) by @shulaoda
- update watch-mode internals for unified FsWatcher (#10736) by @shulaoda

###### ⚡ Performance

- batch `codeSplitting` group `test` / `name` calls (#10745) by @IWANABETHATGUY
- deduplicate used symbol ref readers (#10742) by @Boshen
- reduce release debug formatting (#10728) by @Boshen
- enable compiler cache via `module.enableCompileCache()` (#10678) by @btea
- deduplicate regress codegen (#10732) by @Boshen

###### 🧪 Testing

- define: add expected failure for default parameter scope (#10780) by @hyfdev
- use an absolute filename for transform tsconfig path (#10782) by @shulaoda

###### ⚙️ Miscellaneous Tasks

- deps: upgrade oxc to 0.147.0 (#10767) by @camc314
- deps: update resolver dependencies (#10766) by @Boshen
- deps: update rollup submodule for tests to v4.62.5 (#10770) by @rolldown-guard[bot]
- deps: update dependency vite-plus to ^0.3.0 (#10757) by @renovate[bot]
- deps: update npm packages (#10750) by @renovate[bot]
- deps: update rust crates (#10748) by @renovate[bot]
- deps: update rust crate napi to v3.12.2 (#10738) by @renovate[bot]
- deps: update dependency rust to v1.98.0 (#10733) by @renovate[bot]
- wasi: cap each Node Test attempt with timeout to survive hangs (#10709) by @hyfdev

Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>