feat(transform): respect decorator strictNullChecks option#9580
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shulaoda merged 5 commits intoMay 27, 2026
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Upgrade oxc 0.132.0 -> 0.133.0 (and oxc_resolver 11.19.1 -> 11.19.2) and expose the decorator `strictNullChecks` metadata option added upstream in oxc-project/oxc#22266. transform.decorator.strictNullChecks (default true) controls whether null and undefined are elided from union `design:type` metadata under emitDecoratorMetadata: `string | null` emits `Object` when strict (the default, matching tsc) and `String` when set to false (matching `tsc --strictNullChecks false` and babel-plugin-transform-typescript-metadata). It is threaded through rolldown_common DecoratorOptions (defaulting to oxc's `true` via unwrap_or(true)), the napi binding normalizer, the validator schema, the regenerated binding.d.cts, and the auto-generated --transform.decorator.strict-null-checks CLI flag. It is not inferred from tsconfig.json (oxc_resolver does not parse strictNullChecks). Also handles the upgrade's breaking changes and fallout: - oxc::transformer::DecoratorOptions gained a required strict_null_checks field (manual Default = true). - oxc_minify_napi::CodegenOptions gained legal_comments (set to None); exposed as minify codegen.legalComments in the validator. - Regenerated napi bindings (incl. LegalCommentsMode) and embedded runtime helpers (@oxc-project/runtime 0.133.0). - Refreshed snapshots for oxc's new #__PURE__ / #__NO_SIDE_EFFECTS__ annotation syntax and updated minifier/DCE output. - Added transform tests for both strictNullChecks modes and documented the option in transform.md. Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
…ct-null-checks # Conflicts: # crates/rolldown_common/src/inner_bundler_options/types/transform_option/decorator_options.rs
kylecannon
changed the title
Use a `:::tip` callout instead of a bare blockquote and add a fenced code example showing the per-mode `design:type` result, matching the existing transform/tsconfig option docs. 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
Builds on #9563, which upgraded oxc to
0.133.0and surfaced thestrictNullChecksdecorator-metadata option (from oxc-project/oxc#22266) in the TypeScript types, the validator, and the generated binding.However, #9563's Rust
From<DecoratorOptions> for oxc::transformer::DecoratorOptionshardcodesstrict_null_checks: true, and the napi options normalizer doesn't carry the field, sotransform.decorator.strictNullChecks: falseis currently silently ignored through rolldown's transform/bundle pipeline (the option exists in the type surface but does nothing).This PR wires it through so the option actually takes effect.
What changed
rolldown_common::DecoratorOptionsgains astrict_null_checks: Option<bool>field; itsFromimpl now usesoptions.strict_null_checks.unwrap_or(true)(mirroring oxc's own default) instead of the hardcodedtrue.normalize_binding_transform_optionsforwardsstrict_null_checksfrom the incoming napi options intoDecoratorOptions(previously dropped).transform.md) + tests.Behavior
When
emitDecoratorMetadatais enabled (legacy decorators):strictNullChecks: true(default)strictNullChecks: falsestring | nullObject(matchestscstrict)String(matchestsc --strictNullChecks false/babel-plugin-transform-typescript-metadata)number | undefinedObjectNumberDefaults to
true, so there is no behavior change for existing users; only an explicitstrictNullChecks: falseis newly honored.Follow-up: inferring from
tsconfig.jsonoxc-project/oxc-resolver#1166 (
feat(tsconfig): parse strict and strictNullChecks compiler options) is the enabling resolver-side change. It addsstrict/strictNullCheckstoCompilerOptions, inherits them throughextends, and exposeseffective_strict_null_checks()implementing tsc'sstrictNullChecks ?? strictprecedence.Once it lands and is released, a small downstream follow-up here can forward
compiler_options.effective_strict_null_checks()inmerge_transform_options_with_tsconfigintoDecoratorOptions.strict_null_checks(mappingNoneto the transformer default), plus add the field to the inlineBindingTsconfigCompilerOptionspath, makingstrictNullChecksauto-inferred from tsconfig like the other decorator options. This PR is intentionally scoped to the explicit option so it's useful immediately and independent of that release.Test plan
main(which already has oxc0.133.0);cargo check --workspacepassestransform.test.tscases assertstring | nullemitsObjectby default andStringunderstrictNullChecks: false(verified locally; the full suite runs in CI)AI usage disclosure
Per the AI Usage Policy: AI assistance (Claude Code) was used to implement and verify this change. I have reviewed and tested it locally.
🤖 Generated with Claude Code