fix(dev/lazy): fix exports of lazy requests in lazy chunks by h-a-n-a · Pull Request #9249 · rolldown/rolldown

h-a-n-a · 2026-04-28T11:56:03Z

Summary

This PR fixes a case where dynamic imported chunks in lazy chunks are not able to fetch the correct exports.

Before:

import(`/@vite/lazy?id=…&clientId=…`)

After:

import(`/@vite/lazy?id=…&clientId=…`)
    .then(() => __rolldown_runtime__.loadExports("<stable_proxy_id>"))

When a lazy chunk's body contains import('./another-lazy.js'), the HMR partial
bundle returned the raw chunk namespace (raw lazy chunk) instead of the registered proxy exports,
so inner.foo came back undefined.

In this PR, we intentionally skip loading the raw lazy chunk, instead,
we use __rolldown_runtime__.loadExports(...) to load real module exports.

Test plan

pnpm test:browser — all 7 tests pass with the fix in place
New playground: packages/test-dev-server/tests/playground/lazy-nested-dynamic-import/
Reverted the fix locally → pnpm test:browser -t 'lazy-nested-dynamic-import' fails with
inner.foo = UNDEFINED / inner.bar = UNDEFINED
Restored the fix → test passes on first try (~135 ms, no retry)
pnpm run lint-knip clean for the new playground

h-a-n-a · 2026-04-28T11:56:16Z

fix(dev/lazy): fix exports of lazy requests in lazy chunks #9249 : 2 dependent PRs (#9275 , #9303 ) 👈 (View in Graphite)
fix(rolldown_plugin_lazy_compilation): use loadExports for fetched proxy to preserve original export names #9132
fix(dev/lazy): lazily compiled modules should be watched #9301
main

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codspeed-hq · 2026-05-11T08:09:40Z

Merging this PR will not alter performance

✅ 4 untouched benchmarks
⏩ 10 skipped benchmarks¹

_{Comparing 04-28-fix_dev_lazy_fix_exports_of_lazy_requests_in_lazy_chunks (f2ff2a6) with main (8ada1f7)²}

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. ↩
No successful run was found on main (07da851) during the generation of this report, so 8ada1f7 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

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h-a-n-a · 2026-05-12T02:04:34Z

Merge activity

May 12, 2:04 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 12, 2:04 AM UTC: h-a-n-a added this pull request to the Graphite merge queue.
May 12, 2:09 AM UTC: Merged by the Graphite merge queue.

## Summary This PR fixes a case where dynamic imported chunks in lazy chunks are not able to fetch the correct exports. Before: ```js import(`/@vite/lazy?id=…&clientId=…`) ``` After: ```js import(`/@vite/lazy?id=…&clientId=…`) .then(() => __rolldown_runtime__.loadExports("<stable_proxy_id>")) ``` When a lazy chunk's body contains `import('./another-lazy.js')`, the HMR partial bundle returned the raw chunk namespace (raw lazy chunk) instead of the registered proxy exports, so `inner.foo` came back `undefined`. In this PR, we intentionally skip loading the raw lazy chunk, instead, we use `__rolldown_runtime__.loadExports(...)` to load real module exports. ## Test plan - [x] `pnpm test:browser` — all 7 tests pass with the fix in place - [x] New playground: `packages/test-dev-server/tests/playground/lazy-nested-dynamic-import/` - [x] Reverted the fix locally → `pnpm test:browser -t 'lazy-nested-dynamic-import'` fails with `inner.foo = UNDEFINED` / `inner.bar = UNDEFINED` - [x] Restored the fix → test passes on first try (~135 ms, no retry) - [x] `pnpm run lint-knip` clean for the new playground

@shulaoda

## [1.0.1] - 2026-05-13 ### 🚀 Features - experimental/lazy-barrel: advice on oversized barrel modules (#9236) by @shulaoda - rolldown: inline optional-chain enum access (#9379) by @Dunqing - chunk-optimization: dedupe already-loaded dynamic deps (#9305) by @IWANABETHATGUY - binding: call moduleParsed hook in ParallelJsPlugin (#9318) by @jaehafe ### 🐛 Bug Fixes - transform: enable `enum_eval` for `transformSync` and vite TS transform (#9325) by @Dunqing - error: remove severity prefix from diagnostic messages (#9262) by @Kyujenius - deps: pin pnpm to 10.23.0 to work around catalog mismatch on Netlify (#9364) by @shulaoda - ci: pin mimalloc-safe to 0.1.58 (#9361) by @shulaoda - dev/lazy: fix exports of lazy requests in lazy chunks (#9249) by @h-a-n-a - rolldown_plugin_vite_resolve: handle errors in `resolveSubpathImports` callback (#9355) by @sapphi-red - rolldown_plugin_lazy_compilation: use loadExports for fetched proxy to preserve original export names (#9132) by @h-a-n-a - common: include offending index in HybridIndexVec panic message (#9296) by @SAY-5 ### 🚜 Refactor - ecmascript: extract semantic_builder_for_transform helper (#9326) by @Dunqing - test: extract reusable static-import-cycle helper (#9332) by @IWANABETHATGUY ### 📚 Documentation - clarify scope of `topLevelVar` (#9380) by @IWANABETHATGUY - meta/design: add ast-mutation design doc (#9338) by @hyf0 - feat: add ai policy in contribution guide (#9315) by @mdong1909 ### ⚡ Performance - binding: enable mimalloc v3 to reduce idle memory (#9349) by @shulaoda ### 🧪 Testing - mcs: cover require() in `$initial` group (#9376) by @hyf0 - add regression for CJS facade chunk merge into entry (#9351) by @IWANABETHATGUY ### ⚙️ Miscellaneous Tasks - switch prepare-release to manual dispatch with version input (#9383) by @shulaoda - migrate `@rolldown/pluginutils` to `rolldown/plugins` (#9317) by @shulaoda - deps: pin libmimalloc-sys2 to 0.1.54 (#9372) by @shulaoda - replace `igorskyflyer/action-readfile` with `cat` (#9369) by @sapphi-red - deps: update test262 submodule for tests (#9371) by @rolldown-guard[bot] - use app token for test dep update PRs (#9368) by @sapphi-red - replace some actions with gh commands (#9367) by @sapphi-red - replace action-semantic-pull-request with inline regex (#9366) by @sapphi-red - remove pull_request_target workflows (#9188) by @Boshen - deps: upgrade oxc to 0.130.0 (#9360) by @shulaoda - deps: update github actions (major) (#9348) by @renovate[bot] - deps: update github actions (#9341) by @renovate[bot] - deps: update rust crates (#9344) by @renovate[bot] - deps: update crate-ci/typos action to v1.46.1 (#9357) by @renovate[bot] - deps: update npm packages (#9343) by @renovate[bot] - deps: update pnpm to v10.33.4 (#9347) by @renovate[bot] - deps: update dependency rolldown-plugin-dts to ^0.25.0 (#9346) by @renovate[bot] - .claude: add rolldown-repl encoder, rename decode skill (#9352) by @IWANABETHATGUY - deps: update crate-ci/typos action to v1.46.0 (#9345) by @renovate[bot] - deps: update napi to v3.8.6 (#9342) by @renovate[bot] - deps: update dependency vite-plus to v0.1.20 (#9340) by @renovate[bot] - enable rollup chunking-form test (#9335) by @IWANABETHATGUY - typo: fix typo in watcher options comment (#9324) by @thescripted ### ❤️ New Contributors * @Kyujenius made their first contribution in [#9262](#9262) * @SAY-5 made their first contribution in [#9296](#9296) * @thescripted made their first contribution in [#9324](#9324) Co-authored-by: shulaoda <[email protected]>

## Summary This PR fixes a case where dynamic imported chunks in lazy chunks are not able to fetch the correct exports. Before: ```js import(`/@vite/lazy?id=…&clientId=…`) ``` After: ```js import(`/@vite/lazy?id=…&clientId=…`) .then(() => __rolldown_runtime__.loadExports("<stable_proxy_id>")) ``` When a lazy chunk's body contains `import('./another-lazy.js')`, the HMR partial bundle returned the raw chunk namespace (raw lazy chunk) instead of the registered proxy exports, so `inner.foo` came back `undefined`. In this PR, we intentionally skip loading the raw lazy chunk, instead, we use `__rolldown_runtime__.loadExports(...)` to load real module exports. ## Test plan - [x] `pnpm test:browser` — all 7 tests pass with the fix in place - [x] New playground: `packages/test-dev-server/tests/playground/lazy-nested-dynamic-import/` - [x] Reverted the fix locally → `pnpm test:browser -t 'lazy-nested-dynamic-import'` fails with `inner.foo = UNDEFINED` / `inner.bar = UNDEFINED` - [x] Restored the fix → test passes on first try (~135 ms, no retry) - [x] `pnpm run lint-knip` clean for the new playground

@shulaoda

## [1.0.1] - 2026-05-13 ### 🚀 Features - experimental/lazy-barrel: advice on oversized barrel modules (#9236) by @shulaoda - rolldown: inline optional-chain enum access (#9379) by @Dunqing - chunk-optimization: dedupe already-loaded dynamic deps (#9305) by @IWANABETHATGUY - binding: call moduleParsed hook in ParallelJsPlugin (#9318) by @jaehafe ### 🐛 Bug Fixes - transform: enable `enum_eval` for `transformSync` and vite TS transform (#9325) by @Dunqing - error: remove severity prefix from diagnostic messages (#9262) by @Kyujenius - deps: pin pnpm to 10.23.0 to work around catalog mismatch on Netlify (#9364) by @shulaoda - ci: pin mimalloc-safe to 0.1.58 (#9361) by @shulaoda - dev/lazy: fix exports of lazy requests in lazy chunks (#9249) by @h-a-n-a - rolldown_plugin_vite_resolve: handle errors in `resolveSubpathImports` callback (#9355) by @sapphi-red - rolldown_plugin_lazy_compilation: use loadExports for fetched proxy to preserve original export names (#9132) by @h-a-n-a - common: include offending index in HybridIndexVec panic message (#9296) by @SAY-5 ### 🚜 Refactor - ecmascript: extract semantic_builder_for_transform helper (#9326) by @Dunqing - test: extract reusable static-import-cycle helper (#9332) by @IWANABETHATGUY ### 📚 Documentation - clarify scope of `topLevelVar` (#9380) by @IWANABETHATGUY - meta/design: add ast-mutation design doc (#9338) by @hyf0 - feat: add ai policy in contribution guide (#9315) by @mdong1909 ### ⚡ Performance - binding: enable mimalloc v3 to reduce idle memory (#9349) by @shulaoda ### 🧪 Testing - mcs: cover require() in `$initial` group (#9376) by @hyf0 - add regression for CJS facade chunk merge into entry (#9351) by @IWANABETHATGUY ### ⚙️ Miscellaneous Tasks - switch prepare-release to manual dispatch with version input (#9383) by @shulaoda - migrate `@rolldown/pluginutils` to `rolldown/plugins` (#9317) by @shulaoda - deps: pin libmimalloc-sys2 to 0.1.54 (#9372) by @shulaoda - replace `igorskyflyer/action-readfile` with `cat` (#9369) by @sapphi-red - deps: update test262 submodule for tests (#9371) by @rolldown-guard[bot] - use app token for test dep update PRs (#9368) by @sapphi-red - replace some actions with gh commands (#9367) by @sapphi-red - replace action-semantic-pull-request with inline regex (#9366) by @sapphi-red - remove pull_request_target workflows (#9188) by @Boshen - deps: upgrade oxc to 0.130.0 (#9360) by @shulaoda - deps: update github actions (major) (#9348) by @renovate[bot] - deps: update github actions (#9341) by @renovate[bot] - deps: update rust crates (#9344) by @renovate[bot] - deps: update crate-ci/typos action to v1.46.1 (#9357) by @renovate[bot] - deps: update npm packages (#9343) by @renovate[bot] - deps: update pnpm to v10.33.4 (#9347) by @renovate[bot] - deps: update dependency rolldown-plugin-dts to ^0.25.0 (#9346) by @renovate[bot] - .claude: add rolldown-repl encoder, rename decode skill (#9352) by @IWANABETHATGUY - deps: update crate-ci/typos action to v1.46.0 (#9345) by @renovate[bot] - deps: update napi to v3.8.6 (#9342) by @renovate[bot] - deps: update dependency vite-plus to v0.1.20 (#9340) by @renovate[bot] - enable rollup chunking-form test (#9335) by @IWANABETHATGUY - typo: fix typo in watcher options comment (#9324) by @thescripted ### ❤️ New Contributors * @Kyujenius made their first contribution in [#9262](#9262) * @SAY-5 made their first contribution in [#9296](#9296) * @thescripted made their first contribution in [#9324](#9324) Co-authored-by: shulaoda <[email protected]>

github-actions Bot assigned h-a-n-a Apr 28, 2026

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h-a-n-a mentioned this pull request Apr 29, 2026

fix(dev): apply __toCommonJS interop when CJS requires ESM in HMR finalizer #9261

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wip: disable node_modules watch #9275

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fix(dev/lazy): lazily compiled modules should be watched #9301

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wip: disable node_modules watch #9303

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release: v1.0.1 #9384

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fix(dev/lazy): fix exports of lazy requests in lazy chunks#9249

fix(dev/lazy): fix exports of lazy requests in lazy chunks#9249
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