feat(treeshake): add `invalidImportSideEffects` option by shulaoda · Pull Request #7958 · rolldown/rolldown

shulaoda · 2026-01-19T19:06:13Z

This is useful for lazy barrel optimization. Rspack automatically simplifies unused import statements to import '..', which helps avoid unnecessary module loading. We could implement this as well, but doing it via the minifier would be simpler.

shulaoda · 2026-01-19T19:06:36Z

feat(treeshake): add invalidImportSideEffects option #7958 👈 (View in Graphite)
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Pull request overview

This PR adds the invalidImportSideEffects option to the treeshaking configuration, which controls whether invalid import statements should be assumed to have side effects. This feature is useful for lazy barrel optimization and aligns with Oxc minifier capabilities.

Changes:

Added new invalidImportSideEffects boolean option to treeshaking configuration with a default value of true
Integrated the option across the TypeScript and Rust layers with proper type definitions, validation, and deserialization
Wired the option to Oxc minifier's invalid_import_side_effects setting

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/rolldown/src/types/module-side-effects.ts	Added TypeScript type definition and JSDoc documentation for the new option
packages/rolldown/src/utils/validator.ts	Updated validation schema to include the new option
packages/rolldown/src/utils/bindingify-input-options.ts	Added option to the binding conversion logic
packages/rolldown/src/binding.d.cts	Added TypeScript declaration for the binding interface
crates/rolldown_testing/_config.schema.json	Updated JSON schema to include the new option
crates/rolldown_common/src/inner_bundler_options/types/treeshake.rs	Added struct field, accessor method, default value, and Oxc integration
crates/rolldown_common/src/inner_bundler_options/mod.rs	Added deserialization logic with proper default handling
crates/rolldown_binding/src/options/binding_input_options/binding_treeshake.rs	Added binding struct field and conversion logic

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packages/rolldown/src/types/module-side-effects.ts

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crates/rolldown_common/src/inner_bundler_options/mod.rs

github-actions · 2026-01-19T21:32:57Z

Benchmarks Rust

target: main(d204cb2)
pr: 01-20-feat_treeshake_add_invalidimportsideeffects_option(7ff7cd7)

group                                                        pr                                     target
-----                                                        --                                     ------
bundle/bundle@multi-duplicated-top-level-symbol              1.00     68.1±2.19ms        ? ?/sec    1.08     73.6±1.79ms        ? ?/sec
bundle/bundle@multi-duplicated-top-level-symbol-sourcemap    1.00     75.7±2.48ms        ? ?/sec    1.03     78.1±3.15ms        ? ?/sec
bundle/bundle@rome_ts                                        1.00    103.0±3.03ms        ? ?/sec    1.01    104.1±1.79ms        ? ?/sec
bundle/bundle@rome_ts-sourcemap                              1.00    112.5±1.69ms        ? ?/sec    1.02    114.6±2.29ms        ? ?/sec
bundle/bundle@threejs                                        1.00     36.7±1.39ms        ? ?/sec    1.00     36.6±0.79ms        ? ?/sec
bundle/bundle@threejs-sourcemap                              1.00     41.2±1.12ms        ? ?/sec    1.02     41.8±0.57ms        ? ?/sec
bundle/bundle@threejs10x                                     1.01    371.0±4.26ms        ? ?/sec    1.00    366.5±4.25ms        ? ?/sec
bundle/bundle@threejs10x-sourcemap                           1.01    430.6±5.90ms        ? ?/sec    1.00    426.5±4.94ms        ? ?/sec
scan/scan@rome_ts                                            1.00     83.4±1.92ms        ? ?/sec    1.02     85.0±2.10ms        ? ?/sec
scan/scan@threejs                                            1.02     29.3±1.62ms        ? ?/sec    1.00     28.7±0.50ms        ? ?/sec
scan/scan@threejs10x                                         1.01    294.0±5.69ms        ? ?/sec    1.00    289.8±5.38ms        ? ?/sec

sapphi-red · 2026-01-20T02:32:36Z

I don't think we should enable this by default. This option ignores sideeffects like

import { nonExisting } from 'foo' // should cause `nonExisting` is not exposed
import 'non-existing' // should cause `non-existing` cannot be resolved

shulaoda · 2026-01-20T08:04:53Z

I don't think we should enable this by default. This option ignores sideeffects like
import { nonExisting } from 'foo' // should cause `nonExisting` is not exposed
import 'non-existing' // should cause `non-existing` cannot be resolved

Oxc enables this by default, which is consistent with the original behavior. Setting invalidImportSideEffects to true means it treats these imports as having side effects, so unused import specifiers will not be removed. Am I misunderstanding this?

sapphi-red · 2026-01-20T08:42:23Z

I don't think we should enable this by default. This option ignores sideeffects like
import { nonExisting } from 'foo' // should cause `nonExisting` is not exposed
import 'non-existing' // should cause `non-existing` cannot be resolved
Oxc enables this by default, which is consistent with the original behavior. Setting invalidImportSideEffects to true means it treats these imports as having side effects, so unused import specifiers will not be removed. Am I misunderstanding this?

Ah, my bad. I misunderstood that you were going to ignore the sideeffects.

sapphi-red · 2026-01-20T08:43:25Z

Merge activity

Jan 20, 8:43 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.
Jan 20, 8:43 AM UTC: sapphi-red added this pull request to the Graphite merge queue.
Jan 20, 8:58 AM UTC: Merged by the Graphite merge queue.

This is useful for lazy barrel optimization. Rspack automatically simplifies unused import statements to `import '..'`, which helps avoid unnecessary module loading. We could implement this as well, but doing it via the minifier would be simpler.

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@IWANABETHATGUY

## [1.0.0-rc.1] - 2026-01-22 ### 🚀 Features - debug_info: add facade chunk elimination reason (#7980) by @IWANABETHATGUY - support lazy barrel optimization (#7933) by @shulaoda - add `experimental.lazyBarrel` option (#7908) by @shulaoda - skip unused external modules from IIFE parameter list (#7978) by @sapphi-red - add custom panic hook for better crash reporting (#7752) by @shulaoda - treeshake: add `invalidImportSideEffects` option (#7958) by @shulaoda - merge allow-extension emitted chunks (#7940) by @IWANABETHATGUY - nativeMagicString generateMap (#7944) by @IWANABETHATGUY - Include meta.magicString in RenderChunkMeta (#7943) by @IWANABETHATGUY - debug_info: add debug info for eliminated facade chunks (#7946) by @IWANABETHATGUY - stablize `strictExecutionOrder` and move to `output.strictExecutionOrder` from `experimental.strictExecutionOrder` (#7901) by @sapphi-red - add documentation link to require() error message (#7898) by @Copilot - add `codeSplitting: boolean` and deprecate `inlineDynamicImports` (#7870) by @hyf0 - dev: change lazy module URL to `/@vite/lazy` from `/lazy` (#7884) by @sapphi-red ### 🐛 Bug Fixes - transform JS files containing `</script>` to escape template literals (#7987) by @IWANABETHATGUY - apply avoid-breaking-exported-api = false to clippy.toml and fix clippy errors (#7982) by @Boshen - pass `kind` from `this.resolve` (#7981) by @sapphi-red - rolldown_plugin_vite_resolve: ignore yarn resolution errors and fallback to other resolvers (#7968) by @sapphi-red - renamer: prevent renaming symbols when there no conflicts (#7936) by @Dunqing - correct minifyInterExports when emitted chunk got merged (#7941) by @IWANABETHATGUY - deduplicate entry points when module is both emitted and dynamically imported (#7885) by @IWANABETHATGUY - dev: add `@vite-ignore` to lazy compilation proxy module import (#7883) by @sapphi-red ### 🚜 Refactor - rust: enable clippy nursery lint group (#8002) by @Boshen - rust: fix inconsistent_struct_constructor clippy lint (#7999) by @Boshen - rust: fix needless_pass_by_ref_mut clippy lint (#7994) by @Boshen - rust: fix unnecessary_wraps clippy lint (#7993) by @Boshen - rust: fix enum_variant_names clippy lint (#7992) by @Boshen - fix single_match clippy lint (#7997) by @Boshen - rust: fix redundant_clone clippy lint (#7996) by @Boshen - rust: rename CJS to Cjs to follow upper_case_acronyms lint (#7991) by @Boshen - rust: remove unnecessary Box wrapper around Vec in MemberExprRef (#7990) by @Boshen - import_record: make resolved_module optional (#7907) by @shulaoda - remove unnecessary `.parse` (#7966) by @sapphi-red - remove unused `ImportRecordMeta::IsPlainImport` (#7948) by @shulaoda - proper set chunk meta (#7939) by @IWANABETHATGUY - module_loader: remove `try_spawn_with_cache` (#7920) by @shulaoda - link_stage: simplify `ImportStatus::NoMatch` to unit variant (#7909) by @shulaoda - improve global scope symbol reservation in chunk deconfliction (#7906) by @IWANABETHATGUY - simplify ast unwrapping in generate stage (#7900) by @IWANABETHATGUY - generate_stage: optimize cross-chunk imports computation (#7889) by @shulaoda - link_stage: move runtime require logic into match branch (#7892) by @shulaoda - link_stage: simplify runtime require reference conditions (#7891) by @shulaoda - link_stage: inline and simplify external dynamic import check (#7890) by @shulaoda - generate_stage: simplify external module import collection logic (#7887) by @shulaoda - avoid redundant module lookup in TLA computation (#7886) by @shulaoda - dev: `devEngine.compileEntry` does not return null (#7882) by @sapphi-red - dev: fix type errors for test HMR runtime (#7881) by @sapphi-red - dev: move `clientId` property to `DevRuntime` base class (#7880) by @sapphi-red - dev: generate client id in browser (#7878) by @hyf0 ### 📚 Documentation - apis: organize hook filters documentation and add composable filters section (#8003) by @sapphi-red - update `vitepress-plugin-group-icons` (#7947) by @yuyinws - add in-depth documentation for lazy barrel optimization (#7969) by @shulaoda - bump theme & update activeMatch for reference (#7963) by @mdong1909 - mark `build()` API as experimental (#7954) by @sapphi-red - enhance search functionality with improved scoring and filtering logic (#7935) by @hyf0 - add minor comments to multiple types (#7930) by @sapphi-red - refactor advanedChunks related content to adapt manual code splitting concept (#7925) by @hyf0 - apis: add content to Bundler API page (#7926) by @sapphi-red - apis: restructure plugin API related docs (#7924) by @sapphi-red - add plugin API docs (#7923) by @sapphi-red - apis: add docs to important APIs (#7913) by @sapphi-red - move the important APIs to the top of the sidebar (#7912) by @sapphi-red - apis: add more content to CLI documentation (#7911) by @sapphi-red - apis: generate CLI docs from --help output (#7910) by @sapphi-red - add fathom analytics (#7896) by @mdong1909 ### ⚡ Performance - use u32 for string indices in string_wizard and rolldown to reduce memory usage (#7989) by @IWANABETHATGUY - rust: remove all usages of `with_scope_tree_child_ids(true)` for `SemanticBuilder` (#7995) by @Dunqing - renamer: skip unnecessary nested scope symbol processing (#7899) by @Dunqing - module_loader: use ArcStr for importer_id to avoid string copy (#7922) by @shulaoda - module_loader: defer `ModuleTaskOwner` construction until needed (#7921) by @shulaoda - renamer: optimize symbol renaming by eliminating `rename_non_root_symbol` pass (#7867) by @Dunqing ### 🧪 Testing - add lazy barrel optimization test cases (#7967) by @shulaoda ### ⚙️ Miscellaneous Tasks - remove lazy barrel option (#8010) by @shulaoda - mark watch API as experimental (#8004) by @sapphi-red - deps: update dependency lodash-es to v4.17.23 [security] (#8001) by @renovate[bot] - git ignore zed local config (#7988) by @IWANABETHATGUY - setup publint for published packages (#7972) by @Copilot - enable `tagged_template_transform ` uncondionally (#7975) by @IWANABETHATGUY - deps: update oxc to v0.110.0 (#7964) by @renovate[bot] - deps: update oxc apps (#7962) by @renovate[bot] - ai: add upgrade-oxc Claude skill (#7957) by @Boshen - deps: update rollup submodule for tests to v4.55.2 (#7959) by @sapphi-red - deps: update test262 submodule for tests (#7960) by @sapphi-red - deps: update crate-ci/typos action to v1.42.1 (#7961) by @renovate[bot] - deps: update rust crates (#7951) by @renovate[bot] - deps: update npm packages (#7953) by @renovate[bot] - deps: update github-actions (#7952) by @renovate[bot] - deps: update npm packages (#7950) by @renovate[bot] - format magic-string test before write to disk (#7945) by @IWANABETHATGUY - deps: update dependency rolldown-plugin-dts to ^0.21.0 (#7915) by @renovate[bot] - deps: update dependency oxlint-tsgolint to v0.11.1 (#7914) by @renovate[bot] - deps: update dependency diff to v8.0.3 [security] (#7904) by @renovate[bot] - remove outdated TODO comment in `collect_depended_symbols` (#7888) by @shulaoda - deps: update oxc resolver to v11.16.3 (#7876) by @renovate[bot]

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shulaoda changed the title ~~feat(treeshake): add invalidImportSideEffects option~~ feat(treeshake): add invalidImportSideEffects option Jan 19, 2026

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feat(treeshake): add `invalidImportSideEffects` option#7958

feat(treeshake): add `invalidImportSideEffects` option#7958
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