refactor: distinguish `map: null` vs `map: undefined` in transform hook output by sapphi-red · Pull Request #9497 · rolldown/rolldown

sapphi-red · 2026-05-21T11:13:07Z

To emit SOURCEMAP_BROKEN warning, we need to distinguish map: null and map: undefined.

sapphi-red · 2026-05-21T11:13:28Z

How to use the Graphite Merge Queue

Add 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.

netlify · 2026-05-21T11:14:26Z

✅ Deploy Preview for rolldown-rs canceled.

Name	Link
🔨 Latest commit	`e412df1`
🔍 Latest deploy log	https://app.netlify.com/projects/rolldown-rs/deploys/6a0fbddafe20fa000844cbf2

sapphi-red · 2026-05-22T02:08:33Z

Merge activity

May 22, 2:08 AM UTC: The merge label 'graphite: merge-when-ready' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
May 22, 2:21 AM UTC: sapphi-red added this pull request to the Graphite merge queue.
May 22, 2:25 AM UTC: Merged by the Graphite merge queue.

codspeed-hq · 2026-05-22T02:14:16Z

Merging this PR will not alter performance

✅ 4 untouched benchmarks
⏩ 10 skipped benchmarks¹

_{Comparing 05-20-refactor_distinguish_map_null_vs_map_undefined_in_transform_hook_output (5e26476) with main (997e509)}

10 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

…ok output (#9497) To emit `SOURCEMAP_BROKEN` warning, we need to distinguish `map: null` and `map: undefined`.

Copilot

Pull request overview

Refactors transform-hook sourcemap handling across the TS ↔ Rust boundary to distinguish an explicitly disabled sourcemap (map: null) from an omitted one (map: undefined), aligning with Rollup-style semantics needed for future SOURCEMAP_BROKEN-type warnings.

Changes:

Introduces HookTransformOutputMap in Rust to represent Omitted | Null | Sourcemap.
Updates JS binding + TS typings so transform hooks can round-trip map: null distinctly from omission.
Updates builtin plugins to construct the new map type consistently.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/rolldown/src/plugin/bindingify-build-hooks.ts	Adjusts transform hook binding to preserve `null` vs `undefined` for `map`.
packages/rolldown/src/binding.d.cts	Updates TS declaration to allow `map?: BindingSourcemap \| null`.
crates/rolldown_plugin/src/types/hook_transform_output.rs	Adds `HookTransformOutputMap` enum and updates `HookTransformOutput.map` to use it.
crates/rolldown_plugin/src/plugin_driver/build_hooks.rs	Adapts transform driver to new map type (currently converts back to `Option`).
crates/rolldown_plugin/src/lib.rs	Re-exports `HookTransformOutputMap`.
crates/rolldown_plugin_vite_transform/src/lib.rs	Updates plugin output to use `HookTransformOutputMap` (Omitted vs Sourcemap).
crates/rolldown_plugin_vite_react_refresh_wrapper/src/lib.rs	Uses `HookTransformOutputMap::Null` to explicitly opt out of sourcemaps.
crates/rolldown_plugin_vite_json/src/lib.rs	Converts `SourceMap` into `HookTransformOutputMap`.
crates/rolldown_plugin_vite_import_glob/src/lib.rs	Uses `HookTransformOutputMap::from_if_enabled` for conditional sourcemap generation.
crates/rolldown_plugin_vite_dynamic_import_vars/src/lib.rs	Uses `HookTransformOutputMap::from_if_enabled` for conditional sourcemap generation.
crates/rolldown_plugin_vite_css/src/lib.rs	Updates plugin output to use `HookTransformOutputMap` (Omitted vs Sourcemap).
crates/rolldown_plugin_replace/src/plugin.rs	Uses `HookTransformOutputMap::from_if_enabled` for conditional sourcemap generation.
crates/rolldown_binding/src/options/plugin/types/binding_hook_transform_output.rs	Updates napi binding to decode/encode `map` as sourcemap vs `null` vs omitted.

hyf0 · 2026-05-22T02:32:37Z

        code: normalizedCode,
-        map: bindingifySourcemap(normalizeTransformHookSourcemap(id, code, map)),
+        // Preserve the `map: null` (intentional opt-out) vs `map: undefined`
+        map:
+          bindingifySourcemap(normalizeTransformHookSourcemap(id, code, map)) ??
+          (ret.map === null ? null : undefined),


@sapphi-red cc

hyf0 · 2026-05-22T02:32:52Z

        original_sourcemap_chain = plugin_sourcemap_chain.into_inner();
-        if let Some(map) = self.normalize_transform_sourcemap(r.map, id, &code, r.code.as_ref()) {
+        if let Some(map) =
+          self.normalize_transform_sourcemap(r.map.into_sourcemap(), id, &code, r.code.as_ref())
+        {
          original_sourcemap_chain.push(SourcemapChainElement::Transform((plugin_idx, map)));


@sapphi-red cc

…ok output (rolldown#9497) To emit `SOURCEMAP_BROKEN` warning, we need to distinguish `map: null` and `map: undefined`.

@kylecannon

## [1.0.3] - 2026-05-27 ### 🚀 Features - transform: respect decorator strictNullChecks option (#9580) by @kylecannon - drop `defer` keyword (#9503) by @TheAlexLichter ### 🐛 Bug Fixes - ci: create target dir before cargo release-oxc update (#9584) by @shulaoda - ci: reorder prepare-release steps to avoid dirty git check failure (#9583) by @shulaoda - testing: canonicalize temp dir early and use platform-specific separator in test262 (#9582) by @shulaoda - testing: resolve symlinked temp dir in test262 snapshot normalization (#9581) by @shulaoda - testing: canonicalize temp dir path in test262 snapshot normalization (#9579) by @shulaoda - dev: `onOutput` called twice when initial build fails (#9552) by @hyf0 - dev: make `ensureCurrentBuildFinish` not returning error when engine closes (#9564) by @h-a-n-a - oxc-runtime: route require() to CJS helper variant (#9263) (#9526) by @IWANABETHATGUY - generator: use exporter chunk's export mode for CJS default re-exports (#9299) (#9529) by @IWANABETHATGUY - rolldown: always run reduced-atom static cycle check (#9441) (#9514) by @IWANABETHATGUY - apply transform.dropLabels before scanning (#9521) (#9522) by @IWANABETHATGUY - rolldown_watcher: take `rolldown` dep through the workspace (#9510) by @Boshen - cache: keep the scan-stage cache consistent when a build fails (#9495) by @h-a-n-a - skip JSON default-import namespace optimization for write targets (#9484) (#9489) by @IWANABETHATGUY - deps: skip pnpm frozen-lockfile on Netlify to dodge catalog mismatch bug (#9471) by @Boshen ### 🚜 Refactor - oxc-runtime: use Cow for helper path construction (#9538) by @IWANABETHATGUY - fold import defer phase drop into PreProcessor (#9524) by @IWANABETHATGUY - distinguish `map: null` vs `map: undefined` in transform hook output (#9497) by @sapphi-red ### 📚 Documentation - explain the policy for Rust crates (#9547) by @sapphi-red - cache: add design doc for cache (#9544) by @h-a-n-a - guide/troubleshooting: add TDZ error section (#9537) by @sapphi-red - dev-engine: add design doc for dev-engine (#9479) by @h-a-n-a - lazy-barrel: tweak some words (#9483) by @shulaoda - lazy-barrel: expand reasoning behind LARGE_BARREL_MODULES advice (#9477) by @shulaoda ### ⚡ Performance - generate: thread ast_table by value into codegen consumer (#9555) by @Boshen - finalizers: replace `_reExport` construction with a direct call to avoid calling `clone_in` (#9501) by @Dunqing - reorder hot-path boolean checks to short-circuit on cheap predicates first (#9523) by @Boshen ### 🧪 Testing - rolldown: regression fixture for #9401 (#9418) by @IWANABETHATGUY - failing test for #9441 (#9504) by @TheAlexLichter ### ⚙️ Miscellaneous Tasks - deps: upgrade oxc to 0.133.0 (#9563) by @Dunqing - deps: update crate-ci/typos action to v1.46.3 (#9576) by @renovate[bot] - deps: update mimalloc-safe to 0.1.62 (#9577) by @shulaoda - mimalloc-safe: update to a bug-fix branch for verification (#9569) by @shulaoda - deps: update test262 submodule for tests (#9551) by @rolldown-guard[bot] - point published crates' readme to root README.md (#9553) by @Boshen - replace actions-cool/issues-helper with gh CLI (#9543) by @Boshen - deps: update cargo-shear to 1.12.4 (#9541) by @Boshen - deps: update taiki-e/install-action action to v2.79.4 (#9535) by @renovate[bot] - deps: update github actions (#9532) by @renovate[bot] - deps: update rust crates (#9534) by @renovate[bot] - deps: update npm packages (#9533) by @renovate[bot] - gate experimental/testing-only items to silence dead_code in publish builds (#9517) by @Boshen - docs: deploy to Void (#9509) by @Boshen - release: set up cargo-release-oxc for publishing crates (#9476) by @Boshen - rolldown_plugin_lazy_compilation: add missing description (#9507) by @Boshen - mimalloc-safe: update to a bug-fix branch for verification (#9506) by @shulaoda - deps: update crate-ci/typos action to v1.46.2 (#9468) by @renovate[bot] ### ❤️ New Contributors * @kylecannon made their first contribution in [#9580](#9580)

@kylecannon

## [1.0.3] - 2026-05-27 ### 🚀 Features - transform: respect decorator strictNullChecks option (#9580) by @kylecannon - drop `defer` keyword (#9503) by @TheAlexLichter ### 🐛 Bug Fixes - ci: create target dir before cargo release-oxc update (#9584) by @shulaoda - ci: reorder prepare-release steps to avoid dirty git check failure (#9583) by @shulaoda - testing: canonicalize temp dir early and use platform-specific separator in test262 (#9582) by @shulaoda - testing: resolve symlinked temp dir in test262 snapshot normalization (#9581) by @shulaoda - testing: canonicalize temp dir path in test262 snapshot normalization (#9579) by @shulaoda - dev: `onOutput` called twice when initial build fails (#9552) by @hyf0 - dev: make `ensureCurrentBuildFinish` not returning error when engine closes (#9564) by @h-a-n-a - oxc-runtime: route require() to CJS helper variant (#9263) (#9526) by @IWANABETHATGUY - generator: use exporter chunk's export mode for CJS default re-exports (#9299) (#9529) by @IWANABETHATGUY - rolldown: always run reduced-atom static cycle check (#9441) (#9514) by @IWANABETHATGUY - apply transform.dropLabels before scanning (#9521) (#9522) by @IWANABETHATGUY - rolldown_watcher: take `rolldown` dep through the workspace (#9510) by @Boshen - cache: keep the scan-stage cache consistent when a build fails (#9495) by @h-a-n-a - skip JSON default-import namespace optimization for write targets (#9484) (#9489) by @IWANABETHATGUY - deps: skip pnpm frozen-lockfile on Netlify to dodge catalog mismatch bug (#9471) by @Boshen ### 🚜 Refactor - oxc-runtime: use Cow for helper path construction (#9538) by @IWANABETHATGUY - fold import defer phase drop into PreProcessor (#9524) by @IWANABETHATGUY - distinguish `map: null` vs `map: undefined` in transform hook output (#9497) by @sapphi-red ### 📚 Documentation - explain the policy for Rust crates (#9547) by @sapphi-red - cache: add design doc for cache (#9544) by @h-a-n-a - guide/troubleshooting: add TDZ error section (#9537) by @sapphi-red - dev-engine: add design doc for dev-engine (#9479) by @h-a-n-a - lazy-barrel: tweak some words (#9483) by @shulaoda - lazy-barrel: expand reasoning behind LARGE_BARREL_MODULES advice (#9477) by @shulaoda ### ⚡ Performance - generate: thread ast_table by value into codegen consumer (#9555) by @Boshen - finalizers: replace `_reExport` construction with a direct call to avoid calling `clone_in` (#9501) by @Dunqing - reorder hot-path boolean checks to short-circuit on cheap predicates first (#9523) by @Boshen ### 🧪 Testing - rolldown: regression fixture for #9401 (#9418) by @IWANABETHATGUY - failing test for #9441 (#9504) by @TheAlexLichter ### ⚙️ Miscellaneous Tasks - deps: upgrade oxc to 0.133.0 (#9563) by @Dunqing - deps: update crate-ci/typos action to v1.46.3 (#9576) by @renovate[bot] - deps: update mimalloc-safe to 0.1.62 (#9577) by @shulaoda - mimalloc-safe: update to a bug-fix branch for verification (#9569) by @shulaoda - deps: update test262 submodule for tests (#9551) by @rolldown-guard[bot] - point published crates' readme to root README.md (#9553) by @Boshen - replace actions-cool/issues-helper with gh CLI (#9543) by @Boshen - deps: update cargo-shear to 1.12.4 (#9541) by @Boshen - deps: update taiki-e/install-action action to v2.79.4 (#9535) by @renovate[bot] - deps: update github actions (#9532) by @renovate[bot] - deps: update rust crates (#9534) by @renovate[bot] - deps: update npm packages (#9533) by @renovate[bot] - gate experimental/testing-only items to silence dead_code in publish builds (#9517) by @Boshen - docs: deploy to Void (#9509) by @Boshen - release: set up cargo-release-oxc for publishing crates (#9476) by @Boshen - rolldown_plugin_lazy_compilation: add missing description (#9507) by @Boshen - mimalloc-safe: update to a bug-fix branch for verification (#9506) by @shulaoda - deps: update crate-ci/typos action to v1.46.2 (#9468) by @renovate[bot] ### ❤️ New Contributors * @kylecannon made their first contribution in [#9580](#9580)

github-actions Bot assigned sapphi-red May 21, 2026

This was referenced May 21, 2026

perf: avoid unnecessary intermediate sourcemaps #9500

Closed

feat: add SOURCEMAP_BROKEN warning for renderChunk hook #9499

Closed

feat: add SOURCEMAP_BROKEN warning for transform hook #9498

Closed

sapphi-red force-pushed the 05-20-refactor_distinguish_map_null_vs_map_undefined_in_transform_hook_output branch from aa08857 to 5e26476 Compare May 22, 2026 02:04

sapphi-red marked this pull request as ready for review May 22, 2026 02:08

sapphi-red requested a review from IWANABETHATGUY May 22, 2026 02:08

sapphi-red added the graphite: merge-when-ready label May 22, 2026

hyf0 approved these changes May 22, 2026

View reviewed changes

hyf0 requested a review from Copilot May 22, 2026 02:21

Copilot started reviewing on behalf of hyf0 May 22, 2026 02:21 View session

refactor: distinguish map: null vs map: undefined in transform ho…

e412df1

…ok output (#9497) To emit `SOURCEMAP_BROKEN` warning, we need to distinguish `map: null` and `map: undefined`.

graphite-app Bot force-pushed the 05-20-refactor_distinguish_map_null_vs_map_undefined_in_transform_hook_output branch from 5e26476 to e412df1 Compare May 22, 2026 02:22

graphite-app Bot merged commit e412df1 into main May 22, 2026
32 checks passed

graphite-app Bot removed the graphite: merge-when-ready label May 22, 2026

graphite-app Bot deleted the 05-20-refactor_distinguish_map_null_vs_map_undefined_in_transform_hook_output branch May 22, 2026 02:25

Copilot AI reviewed May 22, 2026

View reviewed changes

V1OL3TF0X pushed a commit to V1OL3TF0X/rolldown that referenced this pull request May 25, 2026

refactor: distinguish map: null vs map: undefined in transform ho…

b899467

…ok output (rolldown#9497) To emit `SOURCEMAP_BROKEN` warning, we need to distinguish `map: null` and `map: undefined`.

rolldown-guard Bot mentioned this pull request May 27, 2026

release: v1.0.3 for rust crates #9585

Merged

shulaoda mentioned this pull request May 27, 2026

release: v1.0.3 #9586

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

refactor: distinguish `map: null` vs `map: undefined` in transform hook output#9497

refactor: distinguish `map: null` vs `map: undefined` in transform hook output#9497
graphite-app[bot] merged 1 commit into
mainfrom
05-20-refactor_distinguish_map_null_vs_map_undefined_in_transform_hook_output

sapphi-red commented May 21, 2026 •

edited

Loading

Uh oh!

sapphi-red commented May 21, 2026

Uh oh!

netlify Bot commented May 21, 2026 •

edited

Loading

Uh oh!

sapphi-red commented May 22, 2026 •

edited by graphite-app Bot

Loading

Uh oh!

codspeed-hq Bot commented May 22, 2026

Uh oh!

Uh oh!

Copilot AI left a comment

Uh oh!

hyf0 May 22, 2026

Uh oh!

hyf0 May 22, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

sapphi-red commented May 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

sapphi-red commented May 21, 2026

How to use the Graphite Merge Queue

Uh oh!

netlify Bot commented May 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

✅ Deploy Preview for rolldown-rs canceled.

Uh oh!

sapphi-red commented May 22, 2026 • edited by graphite-app Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Merge activity

Uh oh!

codspeed-hq Bot commented May 22, 2026

Merging this PR will not alter performance

Footnotes

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

hyf0 May 22, 2026

Choose a reason for hiding this comment

Uh oh!

hyf0 May 22, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

sapphi-red commented May 21, 2026 •

edited

Loading

netlify Bot commented May 21, 2026 •

edited

Loading

sapphi-red commented May 22, 2026 •

edited by graphite-app Bot

Loading