fix: skip JSON default-import namespace optimization for write targets (#9484)#9489
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IWANABETHATGUY
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… write Cover writes via `data[k] = ...` (computed) and `ns.default.foo = ...` (namespace through .default), and skip the read-side optimization for any JSON default that has any member write — otherwise the split `foo` export still inlines the stale constant after mutation. Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
`collect_json_default_imports_with_member_write` walked every stmt_info of every module — wasted work in the common case where the module imports no JSON. Short-circuit when none of the module's resolved import records point at a JSON module. Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
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rolldown#9484) (rolldown#9489) ## Summary Writing to a property of a JSON default import panicked the finalizer with `Always rewrite to MemberExpression for nested MemberExpression`: ```js import data from './data.json'; data.search = 'overridden'; ``` The JSON-default-as-namespace optimization in `bind_imports_and_exports.rs` rewrote `data.search` to the underlying `search` export symbol, collapsing the member expression to a bare identifier (or an inlined constant) — which is invalid as a write target, so `visit_member_expression` hit the `unreachable!`. Fix: skip the optimization when `member_expr_ref.is_write` is true. The write target keeps its structure, `data` resolves normally to `data_default`, and the output becomes `data_default.search = "overridden"` — correctly mutating the underlying object. Closes rolldown#9484. ## Test plan - [x] New fixture `crates/rolldown/tests/rolldown/issues/9484/` reproduces the panic and now produces the expected snapshot. - [x] Full `cargo test --package rolldown --test integration` suite (1717 tests) passes. --------- Co-authored-by: Claude Opus 4.7 (1M context) <[email protected]>
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## [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)
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## [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)
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Summary
Writing to a property of a JSON default import panicked the finalizer with
Always rewrite to MemberExpression for nested MemberExpression:The JSON-default-as-namespace optimization in
bind_imports_and_exports.rsrewrotedata.searchto the underlyingsearchexport symbol, collapsing the member expression to a bare identifier (or an inlined constant) — which is invalid as a write target, sovisit_member_expressionhit theunreachable!.Fix: skip the optimization when
member_expr_ref.is_writeis true. The write target keeps its structure,dataresolves normally todata_default, and the output becomesdata_default.search = "overridden"— correctly mutating the underlying object.Closes #9484.
Test plan
crates/rolldown/tests/rolldown/issues/9484/reproduces the panic and now produces the expected snapshot.cargo test --package rolldown --test integrationsuite (1717 tests) passes.