fix: tree-shake dead dynamic imports to side-effect-free CJS modules#8529
Merged
IWANABETHATGUY merged 1 commit intomainfrom Apr 3, 2026
Merged
Conversation
✅ Deploy Preview for rolldown-rs canceled.
|
Member
Author
How to use the Graphite Merge QueueAdd the label graphite: merge-when-ready to this PR to add it to the merge queue. You must have a Graphite account in order to use the merge queue. Sign up using this link. An organization admin has enabled the Graphite Merge Queue in this repository. Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue. This stack of pull requests is managed by Graphite. Learn more about stacking. |
160f343 to
8865060
Compare
8865060 to
551af3b
Compare
551af3b to
69cfc57
Compare
0c5c116 to
6f69e14
Compare
6f69e14 to
9dab03e
Compare
Merging this PR will not alter performance
Comparing 
Footnotes
|
shulaoda
reviewed
Apr 2, 2026
Member
shulaoda
left a comment
There was a problem hiding this comment.
Perhaps the title should be updated, as this is actually a bug fix.
Member
|
@sapphi-red Could you update the PR title and description to add more context? |
Member
Author
|
(just in case, the test case was made by me but the investigation + fix was done by @IWANABETHATGUY) |
shulaoda
approved these changes
Apr 3, 2026
hyf0
approved these changes
Apr 3, 2026
Member
hyf0
left a comment
There was a problem hiding this comment.
Just verified, the test will fail without this fix. Good job.
This was referenced Apr 8, 2026
Closed
Merged
shulaoda
added a commit
that referenced
this pull request
Apr 8, 2026
## [1.0.0-rc.14] - 2026-04-08 ### 🚀 Features - rust: add `disable_panic_hook` feature to disable the panic hook (#9023) by @sapphi-red - support inlineConst for CJS exports accessed through module.exports (#8976) by @h-a-n-a ### 🐛 Bug Fixes - rolldown_plugin_vite_import_glob: normalize resolved alias path to prevent double slashes (#9032) by @shulaoda - rolldown_plugin_vite_import_glob: follow symlinks in file scanning (#9000) by @Copilot - wrap CJS entry modules for IIFE/UMD when using exports/module (#8999) by @IWANABETHATGUY - emit separate __toESM bindings for mixed ESM/CJS external imports (#8987) by @IWANABETHATGUY - tree-shake dead dynamic imports to side-effect-free CJS modules (#8529) by @sapphi-red - skip inlining stale CJS export constants on module.exports reassignment (#8990) by @IWANABETHATGUY ### 🚜 Refactor - generator: migrate ecma formatting from npx oxfmt to vp fmt (#9022) by @shulaoda - generator: replace npx oxfmt with vp fmt for ecma formatting (#9021) by @shulaoda ### 📚 Documentation - contrib-guide: mention that running tests on older Node.js version will have different stat results (#8996) by @claude ### ⚙️ Miscellaneous Tasks - deps: update npm packages (#9002) by @renovate[bot] - deps: update dependency @napi-rs/cli to v3.6.1 (#9034) by @renovate[bot] - deps: upgrade oxc to 0.124.0 (#9018) by @shulaoda - deps: update test262 submodule for tests (#9010) by @sapphi-red - deps: update dependency oxfmt to ^0.44.0 (#9012) by @renovate[bot] - deps: update dependency vite to v8.0.5 [security] (#9009) by @renovate[bot] - deps: update dependency vite-plus to v0.1.16 (#9008) by @renovate[bot] - deps: update rust crates (#9003) by @renovate[bot] - deps: update github-actions (#9004) by @renovate[bot] - deps: update dependency lodash-es to v4.18.1 [security] (#8992) by @renovate[bot] - deps: update crate-ci/typos action to v1.45.0 (#8988) by @renovate[bot] - upgrade oxc npm packages to 0.123.0 (#8985) by @shulaoda ###◀️ Revert - "chore(deps): update dependency oxfmt to ^0.44.0 (#9012)" (#9019) by @shulaoda Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Dead dynamic imports to side-effect-free CJS modules were not being tree-shaken, producing an unnecessary chunk. The CJS bailout was marking the module as included even though the dynamic entry would later be removed. The fix skips CJS bailout for top-level pure dynamic imports targeting side-effect-free modules.
Found this case while trying to make a smaller repro for #8522 with https://github.com/sapphi-red/zarara.
Playground link