feat(minifier): default `invalid_import_side_effects` to `false` by sapphi-red · Pull Request #18916 · oxc-project/oxc

sapphi-red · 2026-02-04T04:20:05Z

These sideeffects are commonly ignored, so I think we should ignore them by default.

This was originally set to true (#17300) for Rolldown (rolldown/rolldown#7512 (comment)), but that should be instead handled on Rolldown side (rolldown/rolldown#8194).

sapphi-red · 2026-02-04T04:20:22Z

feat(minifier): default invalid_import_side_effects to false #18916 👈 (View in Graphite)
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codspeed-hq · 2026-02-04T04:26:03Z

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing 02-04-feat_minifier_default_invalid_import_side_effects_to_false_ (28b5208) with main (9561e7f)¹}

Summary

✅ 46 untouched benchmarks
⏩ 3 skipped benchmarks²

No successful run was found on main (e7e72e2) during the generation of this report, so 9561e7f was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩
3 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. ↩

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Pull request overview

This PR changes the default value of the invalid_import_side_effects option from true to false, aligning oxc's minifier behavior with industry-standard tools like Rollup, esbuild, and SWC. This option controls whether unused imports are preserved due to potential side effects from invalid imports (which would throw errors at runtime).

Changes:

Updated default value of invalid_import_side_effects from true to false in TreeShakeOptions
Added test cases to cover both the new default behavior (removing unused imports) and the old behavior (preserving unused imports when invalid_import_side_effects: true)
Updated memory allocation snapshot reflecting fewer system reallocs with the new default

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
crates/oxc_minifier/src/options.rs	Changed `invalid_import_side_effects` default from `true` to `false` and updated documentation
crates/oxc_minifier/tests/peephole/remove_unused_declaration.rs	Updated tests to use new default and added test cases for old behavior with explicit `invalid_import_side_effects: true`
tasks/track_memory_allocations/allocs_minifier.snap	Updated memory allocation metrics showing reduced reallocs (3→0) for RadixUIAdoptionSection.jsx

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Boshen · 2026-02-04T05:41:12Z

Merge activity

Feb 4, 5:41 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Feb 4, 5:41 AM UTC: Boshen added this pull request to the Graphite merge queue.
Feb 4, 5:51 AM UTC: Merged by the Graphite merge queue.

) These sideeffects are commonly ignored, so I think we should ignore them by default. - [Rollup REPL](https://rollupjs.org/repl/?version=4.57.1&shareable=eyJleGFtcGxlIjpudWxsLCJtb2R1bGVzIjpbeyJjb2RlIjoiaW1wb3J0IHsgZm9vIH0gZnJvbSAndW5rbm93bidcbmlmIChmYWxzZSkge1xuICBjb25zb2xlLmxvZyhmb28pXG59IiwiaXNFbnRyeSI6dHJ1ZSwibmFtZSI6Im1haW4uanMifV0sIm9wdGlvbnMiOnt9fQ==) - [esbuild try](https://esbuild.github.io/try/#dAAwLjI3LjIALS1taW5pZnkAaW1wb3J0IHsgZm9vIH0gZnJvbSAndW5rbm93bicKaWYgKGZhbHNlKSB7CiAgY29uc29sZS5sb2coZm9vKQp9) - [SWC playground](https://play.swc.rs/?version=1.15.11&code=H4sIAAAAAAAAAw3LMQ6AIBAEwP6S%2B8N2YOOfjOEMEW4NaCwIf9fpJ9eL7caAkZiwxorw%2BOl8PahkQ7St9LRgqAA7vbOktfCI%2F1hUpsoHV0iLrEQAAAA%3D&config=H4sIAAAAAAAAA41VS47bMAzd5xSB111MB0VR9ADd9QyCYlGOMrJoiFQ%2BGOTupRU7k5nQRjdBzKdHiuQj9b7ZbpsDtc3v7bv8lY%2FBZoJ8%2FxYLXRLbs1gaaHtLbQ4DN99m9EAj5G0kqKbrDWnY5g64suj15fXHxGgiIsHMmGx9SMFfHmO22A8ZiB5sYhWXpYfE9Jk%2FYRlPI8C5PNp3iBFsWkGMJRMSQwdZc9xijHYgMEebFS%2FjTW0OhFqIESwMzgwZBxVPLnDAJDGfUQfWmRYdKFDI0HI4gkaTWEJLJOkp%2BVTYwa50Xe3zFzYcbSyWlZhwri2R2ype9xiIjS9JK%2BENXKjBDZyK%2B5UZvMnAJadn3gFDWujJG4BUIFqiZHvQ%2FNYTXvS0xParzJC8SJYvCi761rJM0ElRTQheqexYGcgctG5mcKWFsbKtdp0JXigfBQcGvBetKK7pFLjda0H5MgB6BZD%2BWq%2Bp6gaY%2BxQu4ONArMB%2FJEvWBTad6C3vl1G69DuMKwF64D26lQPSCsZlOMuWOA%2FLeEkORBrg1COFKvC8BGQAGE2s%2B%2FJJGzIe4tF0EXcfa2I6cL3v4d6mrs77w75kHCIcIS7J%2BD9GZBWVux1HVc%2BT%2FTS98EsTpZXBC99fPj0bkspm%2Fq1JNT268pBQ1eTtOfnZfByaX465ak2gvzNRKv6W8JSazfUfly9ihugGAAA%3D) This was originally set to `true` (#17300) for Rolldown (rolldown/rolldown#7512 (comment)), but that should be instead handled on Rolldown side (rolldown/rolldown#8194).

### 💥 BREAKING CHANGES - 2bf7293 mangler: [**BREAKING**] Enable `top_level` by default for modules and commonjs (#18278) (sapphi-red) - 48b0542 span: [**BREAKING**] SourceType::ts should set module to unambigious (#18873) (Boshen) ### 🚀 Features - 500d071 minifier: Local traverse ctx and generated minifier traverse (#19106) (Boshen) - 142a1be parser: Detect binary files with TS1490 error (#19047) (Boshen) - e316857 allocator/bitset: Add `Ones` iterator to `BitSet` (#19027) (sapphi-red) - 742ad3f minifier: Default `invalid_import_side_effects` to `false` (#18916) (sapphi-red) - 0eff6be parser: Error JSX-like type assertions and generics in `.mts`/`.cts` (#18910) (Boshen) - 18320c6 span: Store file extension in `SourceType` (#18893) (Boshen) ### 🐛 Bug Fixes - a7514e4 isolated-declarations: Preserve const context in literal type inference (#19178) (camc314) - 312e756 isolated-declarations: Preserve readonly literal initializers (#19177) (camc314) - d0ca8d0 isolated-declarations: Skip parenthesis when inferring type (#19176) (camc314) - 110c300 oxc_ecmascript: `+[false]` and `+[true]` should evaluate to `NaN` (#19174) (copilot-swe-agent) - f32ea19 semantic: Report redeclaration error for import bindings conflicting with value declarations (#19068) (Boshen) - 3aeba7a semantic: Report redeclaration error for `function a() {} var a` in module mode (#19041) (Boshen) - 35e32c6 coverage: Match Babel's options.json inheritance for test fixtures (#19002) (Boshen) - 463d60d semantic: Skip TS2391 for standalone computed-name class methods (#19025) (Boshen) - 56c086b parser: Add modifier ordering validation (TS1029) (#19024) (Boshen) - 6067a49 linter/jsdoc: False positive in `check-tag-names` for `@` in email addresses and npm scopes (#19021) (Boshen) - b13bb70 semantic/jsdoc: Inline tags like `{@link}` break jsdoc parsing (#19019) (Boshen) - e3609e3 regular_expression: Preserve UnicodeEscape CharacterKind in string literals (#18998) (Boshen) - 57917ee parser: Parse decorators on rest parameters (#18938) (Boshen) - 487601b napi: Disable mimalloc on Windows to fix worker_threads crash (#18923) (Boshen) - 1f6b193 parser: Validate TypeScript import type options (#18889) (Boshen) - 1663184 parser: Allow conditional types in function type parameters (#18886) (Boshen) - 5758046 parser: Error on property access after instantiation expression (#18887) (Boshen) - 5eb4a94 parser: Handle `<<` as two `<` tokens in type argument contexts (#18885) (Boshen) ### ⚡ Performance - ed8c054 oxc_str: Add precomputed hash to Ident for fast HashMap lookups (#19143) (Boshen) - d4a0867 transformer_plugins: Switch ReplaceGlobalDefines from Traverse to VisitMut (#19146) (Boshen) - 9eb16b3 syntax: Pack ASCII identifier tables into single bitflag table (#19088) (Boshen) - e7595d1 mangler: Use BitSet for exported symbols set (#19023) (sapphi-red) - 2537924 semantic: Optimize scope resolution with fast paths and inlining (#19029) (Boshen) - 69a8d85 mangler: Use BitSet for keep_names symbols set (#19028) (sapphi-red) - f78c525 parser: Try hybrid parsing for jsx children and closing element/fragments (#18789) (camchenry) Co-authored-by: camc314 <[email protected]>

### 💥 BREAKING CHANGES - 2bf7293 mangler: [**BREAKING**] Enable `top_level` by default for modules and commonjs (oxc-project#18278) (sapphi-red) - 48b0542 span: [**BREAKING**] SourceType::ts should set module to unambigious (oxc-project#18873) (Boshen) ### 🚀 Features - 500d071 minifier: Local traverse ctx and generated minifier traverse (oxc-project#19106) (Boshen) - 142a1be parser: Detect binary files with TS1490 error (oxc-project#19047) (Boshen) - e316857 allocator/bitset: Add `Ones` iterator to `BitSet` (oxc-project#19027) (sapphi-red) - 742ad3f minifier: Default `invalid_import_side_effects` to `false` (oxc-project#18916) (sapphi-red) - 0eff6be parser: Error JSX-like type assertions and generics in `.mts`/`.cts` (oxc-project#18910) (Boshen) - 18320c6 span: Store file extension in `SourceType` (oxc-project#18893) (Boshen) ### 🐛 Bug Fixes - a7514e4 isolated-declarations: Preserve const context in literal type inference (oxc-project#19178) (camc314) - 312e756 isolated-declarations: Preserve readonly literal initializers (oxc-project#19177) (camc314) - d0ca8d0 isolated-declarations: Skip parenthesis when inferring type (oxc-project#19176) (camc314) - 110c300 oxc_ecmascript: `+[false]` and `+[true]` should evaluate to `NaN` (oxc-project#19174) (copilot-swe-agent) - f32ea19 semantic: Report redeclaration error for import bindings conflicting with value declarations (oxc-project#19068) (Boshen) - 3aeba7a semantic: Report redeclaration error for `function a() {} var a` in module mode (oxc-project#19041) (Boshen) - 35e32c6 coverage: Match Babel's options.json inheritance for test fixtures (oxc-project#19002) (Boshen) - 463d60d semantic: Skip TS2391 for standalone computed-name class methods (oxc-project#19025) (Boshen) - 56c086b parser: Add modifier ordering validation (TS1029) (oxc-project#19024) (Boshen) - 6067a49 linter/jsdoc: False positive in `check-tag-names` for `@` in email addresses and npm scopes (oxc-project#19021) (Boshen) - b13bb70 semantic/jsdoc: Inline tags like `{@link}` break jsdoc parsing (oxc-project#19019) (Boshen) - e3609e3 regular_expression: Preserve UnicodeEscape CharacterKind in string literals (oxc-project#18998) (Boshen) - 57917ee parser: Parse decorators on rest parameters (oxc-project#18938) (Boshen) - 487601b napi: Disable mimalloc on Windows to fix worker_threads crash (oxc-project#18923) (Boshen) - 1f6b193 parser: Validate TypeScript import type options (oxc-project#18889) (Boshen) - 1663184 parser: Allow conditional types in function type parameters (oxc-project#18886) (Boshen) - 5758046 parser: Error on property access after instantiation expression (oxc-project#18887) (Boshen) - 5eb4a94 parser: Handle `<<` as two `<` tokens in type argument contexts (oxc-project#18885) (Boshen) ### ⚡ Performance - ed8c054 oxc_str: Add precomputed hash to Ident for fast HashMap lookups (oxc-project#19143) (Boshen) - d4a0867 transformer_plugins: Switch ReplaceGlobalDefines from Traverse to VisitMut (oxc-project#19146) (Boshen) - 9eb16b3 syntax: Pack ASCII identifier tables into single bitflag table (oxc-project#19088) (Boshen) - e7595d1 mangler: Use BitSet for exported symbols set (oxc-project#19023) (sapphi-red) - 2537924 semantic: Optimize scope resolution with fast paths and inlining (oxc-project#19029) (Boshen) - 69a8d85 mangler: Use BitSet for keep_names symbols set (oxc-project#19028) (sapphi-red) - f78c525 parser: Try hybrid parsing for jsx children and closing element/fragments (oxc-project#18789) (camchenry) Co-authored-by: camc314 <[email protected]>

refs oxc-project/oxc#18916

### 💥 BREAKING CHANGES - 2bf7293 mangler: [**BREAKING**] Enable `top_level` by default for modules and commonjs (oxc-project#18278) (sapphi-red) - 48b0542 span: [**BREAKING**] SourceType::ts should set module to unambigious (oxc-project#18873) (Boshen) ### 🚀 Features - 500d071 minifier: Local traverse ctx and generated minifier traverse (oxc-project#19106) (Boshen) - 142a1be parser: Detect binary files with TS1490 error (oxc-project#19047) (Boshen) - e316857 allocator/bitset: Add `Ones` iterator to `BitSet` (oxc-project#19027) (sapphi-red) - 742ad3f minifier: Default `invalid_import_side_effects` to `false` (oxc-project#18916) (sapphi-red) - 0eff6be parser: Error JSX-like type assertions and generics in `.mts`/`.cts` (oxc-project#18910) (Boshen) - 18320c6 span: Store file extension in `SourceType` (oxc-project#18893) (Boshen) ### 🐛 Bug Fixes - a7514e4 isolated-declarations: Preserve const context in literal type inference (oxc-project#19178) (camc314) - 312e756 isolated-declarations: Preserve readonly literal initializers (oxc-project#19177) (camc314) - d0ca8d0 isolated-declarations: Skip parenthesis when inferring type (oxc-project#19176) (camc314) - 110c300 oxc_ecmascript: `+[false]` and `+[true]` should evaluate to `NaN` (oxc-project#19174) (copilot-swe-agent) - f32ea19 semantic: Report redeclaration error for import bindings conflicting with value declarations (oxc-project#19068) (Boshen) - 3aeba7a semantic: Report redeclaration error for `function a() {} var a` in module mode (oxc-project#19041) (Boshen) - 35e32c6 coverage: Match Babel's options.json inheritance for test fixtures (oxc-project#19002) (Boshen) - 463d60d semantic: Skip TS2391 for standalone computed-name class methods (oxc-project#19025) (Boshen) - 56c086b parser: Add modifier ordering validation (TS1029) (oxc-project#19024) (Boshen) - 6067a49 linter/jsdoc: False positive in `check-tag-names` for `@` in email addresses and npm scopes (oxc-project#19021) (Boshen) - b13bb70 semantic/jsdoc: Inline tags like `{@link}` break jsdoc parsing (oxc-project#19019) (Boshen) - e3609e3 regular_expression: Preserve UnicodeEscape CharacterKind in string literals (oxc-project#18998) (Boshen) - 57917ee parser: Parse decorators on rest parameters (oxc-project#18938) (Boshen) - 487601b napi: Disable mimalloc on Windows to fix worker_threads crash (oxc-project#18923) (Boshen) - 1f6b193 parser: Validate TypeScript import type options (oxc-project#18889) (Boshen) - 1663184 parser: Allow conditional types in function type parameters (oxc-project#18886) (Boshen) - 5758046 parser: Error on property access after instantiation expression (oxc-project#18887) (Boshen) - 5eb4a94 parser: Handle `<<` as two `<` tokens in type argument contexts (oxc-project#18885) (Boshen) ### ⚡ Performance - ed8c054 oxc_str: Add precomputed hash to Ident for fast HashMap lookups (oxc-project#19143) (Boshen) - d4a0867 transformer_plugins: Switch ReplaceGlobalDefines from Traverse to VisitMut (oxc-project#19146) (Boshen) - 9eb16b3 syntax: Pack ASCII identifier tables into single bitflag table (oxc-project#19088) (Boshen) - e7595d1 mangler: Use BitSet for exported symbols set (oxc-project#19023) (sapphi-red) - 2537924 semantic: Optimize scope resolution with fast paths and inlining (oxc-project#19029) (Boshen) - 69a8d85 mangler: Use BitSet for keep_names symbols set (oxc-project#19028) (sapphi-red) - f78c525 parser: Try hybrid parsing for jsx children and closing element/fragments (oxc-project#18789) (camchenry) Co-authored-by: camc314 <[email protected]>

github-actions bot added A-minifier Area - Minifier C-enhancement Category - New feature or request labels Feb 4, 2026

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sapphi-red mentioned this pull request Feb 4, 2026

feat(minifier): update invalidImportSideEffects default value oxc-project/website#863

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This was referenced Feb 9, 2026

release(crates): oxc v0.113.0 #19167

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release(crates): oxc v0.113.0 #19210

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Boshen mentioned this pull request Feb 10, 2026

release(crates): oxc v0.113.0 #19215

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sapphi-red mentioned this pull request Feb 17, 2026

feat: default treeshake.invalid_import_side_effects to false rolldown/rolldown#8357

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graphite-app bot pushed a commit to rolldown/rolldown that referenced this pull request Feb 17, 2026

feat: default treeshake.invalid_import_side_effects to false (#8357)

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refs oxc-project/oxc#18916

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feat(minifier): default `invalid_import_side_effects` to `false`#18916

feat(minifier): default `invalid_import_side_effects` to `false`#18916
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