feat(minifier): local traverse ctx and generated minifier traverse by Boshen · Pull Request #19106 · oxc-project/oxc

Boshen · 2026-02-07T13:14:53Z

Summary

generate a minifier-local traverse runtime in oxc_minifier
introduce handwritten MinifierTraverseCtx and move prior Ctx functionality into it
remove old Ctx usage and implement the needed traits on MinifierTraverseCtx
wire minifier passes/compressor to use local traverse
reuse ancestor.rs from oxc_traverse via path module in oxc_minifier

Why

avoids orphan-rule friction around implementing traits on the prior context type
keeps minifier traversal concerns local to oxc_minifier

Validation

just fmt
cargo check -p oxc_ast_tools
cargo check -p oxc_minifier
cargo test -p oxc_minifier
just lint

Copilot

Pull request overview

This PR moves the minifier’s traversal runtime to be minifier-local by introducing a dedicated TraverseCtx/MinifierTraverse + generated walker inside oxc_minifier, avoiding orphan-rule constraints and keeping traversal concerns scoped to the minifier.

Changes:

Add an ast_tools generator to produce oxc_minifier’s generated/{traverse,walk}.rs for traversal.
Introduce a new minifier-local traversal context (traverse_context) including ancestry + scoping helpers and UID generation.
Rewire minifier passes (peephole/normalize/compressor) to use the local traversal + reuse Ancestor via #[path] from oxc_traverse.

Reviewed changes

Copilot reviewed 41 out of 45 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tasks/ast_tools/src/main.rs	Adds `oxc_minifier` crate path and wires in the new generator.
tasks/ast_tools/src/generators/mod.rs	Registers the new `MinifierTraverseGenerator`.
tasks/ast_tools/src/generators/minifier_traverse/mod.rs	Generates `oxc_minifier`’s `traverse.rs` and `walk.rs` outputs.
tasks/ast_tools/src/generators/minifier_traverse/walk.rs	Implements codegen for the unsafe walker functions (minifier-local).
tasks/ast_tools/src/generators/minifier_traverse/ancestor.rs	Shared helper logic for “visited fields” / AST filtering (used by minifier traversal generator).
crates/oxc_minifier/src/lib.rs	Switches minifier to use new local traversal modules and generated code.
crates/oxc_minifier/src/generated/mod.rs	Reuses `Ancestor` from `oxc_traverse` and exposes generated `traverse`/`walk`.
crates/oxc_minifier/src/minifier_traverse.rs	Adds `traverse_mut_with_ctx` entry point that enforces ancestry invariants.
crates/oxc_minifier/src/compressor.rs	Uses `ReusableMinifierTraverseCtx` for compression passes.
crates/oxc_minifier/src/traverse_context/mod.rs	Introduces minifier-local `TraverseCtx` with ancestry/scoping/AST builder APIs.
crates/oxc_minifier/src/traverse_context/ancestry.rs	Implements ancestry stack with safe public reads + internal mutation hooks.
crates/oxc_minifier/src/traverse_context/scoping.rs	Adds traversal-time scoping utilities and UID name generation entry point.
crates/oxc_minifier/src/traverse_context/uid.rs	Implements UID generation logic and adds test coverage.
crates/oxc_minifier/src/traverse_context/reusable.rs	Wraps `TraverseCtx` to allow safe reuse across traversals.
crates/oxc_minifier/src/traverse_context/bound_identifier.rs	Adds ergonomic APIs for creating bound identifiers/references.
crates/oxc_minifier/src/traverse_context/maybe_bound_identifier.rs	Adds ergonomic APIs for possibly-bound identifiers/references.
crates/oxc_minifier/src/traverse_context/ecma_context.rs	Implements required ecmascript context traits directly on minifier-local ctx.
crates/oxc_minifier/src/traverse_ast_operations/mod.rs	Introduces helper module for traversal-related AST operations.
crates/oxc_minifier/src/traverse_ast_operations/identifier.rs	Adds `to_identifier` helper with tests.
crates/oxc_minifier/src/traverse_ast_operations/gather_node_parts.rs	Adds Babel-inspired node-name gathering utilities with tests.
crates/oxc_minifier/src/symbol_value.rs	Minor cleanup related to field annotation.
crates/oxc_minifier/src/peephole/mod.rs	Migrates peephole pass to `MinifierTraverse` + local ctx.
crates/oxc_minifier/src/peephole/normalize.rs	Migrates normalize pass to `MinifierTraverse` + local ctx.
crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs	Updates signatures/imports to use minifier-local ctx + ancestor.
crates/oxc_minifier/src/peephole/replace_known_methods.rs	Updates signatures/imports to use minifier-local ctx + ancestor.
crates/oxc_minifier/src/peephole/remove_unused_private_members.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/remove_unused_expression.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/remove_unused_declaration.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/remove_dead_code.rs	Updates signatures/imports to use minifier-local ctx + ancestor.
crates/oxc_minifier/src/peephole/minimize_statements.rs	Updates signatures/imports to use minifier-local ctx + ancestor.
crates/oxc_minifier/src/peephole/minimize_not_expression.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/minimize_logical_expression.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/minimize_if_statement.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/minimize_for_statement.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/minimize_expression_in_boolean_context.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/minimize_conditions.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/minimize_conditional_expression.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/inline.rs	Updates signatures/imports to use minifier-local ctx + ancestor.
crates/oxc_minifier/src/peephole/fold_constants.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/src/peephole/convert_to_dotted_properties.rs	Updates signatures/imports to use minifier-local ctx.
crates/oxc_minifier/Cargo.toml	Adds deps needed by new traversal context/utilities (`oxc_str`, `itoa`).
Cargo.lock	Locks new dependencies for `oxc_minifier`.

crates/oxc_minifier/src/traverse_context/mod.rs

tasks/ast_tools/src/generators/minifier_traverse/walk.rs

tasks/ast_tools/src/generators/minifier_traverse/ancestor.rs

crates/oxc_minifier/src/traverse_context/scoping.rs

codspeed-hq · 2026-02-07T13:20:42Z

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing feat/minifier-traverse-ctx (fbf4af9) with main (8c0ce78)}

Summary

✅ 47 untouched benchmarks
⏩ 3 skipped benchmarks¹

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. ↩

Boshen · 2026-02-09T13:17:34Z

Merge activity

Feb 9, 1:17 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Feb 9, 1:17 PM UTC: Boshen added this pull request to the Graphite merge queue.
Feb 9, 1:24 PM UTC: Merged by the Graphite merge queue.

…19106) ## Summary - generate a minifier-local traverse runtime in `oxc_minifier` - introduce handwritten `MinifierTraverseCtx` and move prior `Ctx` functionality into it - remove old `Ctx` usage and implement the needed traits on `MinifierTraverseCtx` - wire minifier passes/compressor to use local traverse - reuse `ancestor.rs` from `oxc_traverse` via path module in `oxc_minifier` ## Why - avoids orphan-rule friction around implementing traits on the prior context type - keeps minifier traversal concerns local to `oxc_minifier` ## Validation - `just fmt` - `cargo check -p oxc_ast_tools` - `cargo check -p oxc_minifier` - `cargo test -p oxc_minifier` - `just lint`

### 💥 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]>

…xc-project#19106) ## Summary - generate a minifier-local traverse runtime in `oxc_minifier` - introduce handwritten `MinifierTraverseCtx` and move prior `Ctx` functionality into it - remove old `Ctx` usage and implement the needed traits on `MinifierTraverseCtx` - wire minifier passes/compressor to use local traverse - reuse `ancestor.rs` from `oxc_traverse` via path module in `oxc_minifier` ## Why - avoids orphan-rule friction around implementing traits on the prior context type - keeps minifier traversal concerns local to `oxc_minifier` ## Validation - `just fmt` - `cargo check -p oxc_ast_tools` - `cargo check -p oxc_minifier` - `cargo test -p oxc_minifier` - `just lint`

### 💥 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]>

Boshen requested a review from overlookmotel as a code owner February 7, 2026 13:14

Copilot AI review requested due to automatic review settings February 7, 2026 13:14

github-actions bot added A-minifier Area - Minifier A-ast-tools Area - AST tools C-enhancement Category - New feature or request labels Feb 7, 2026

Copilot started reviewing on behalf of Boshen February 7, 2026 13:15 View session

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Boshen added the 0-merge Merge with Graphite Merge Queue label Feb 9, 2026

graphite-app bot force-pushed the feat/minifier-traverse-ctx branch from fbf4af9 to 500d071 Compare February 9, 2026 13:18

graphite-app bot merged commit 500d071 into main Feb 9, 2026
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graphite-app bot deleted the feat/minifier-traverse-ctx branch February 9, 2026 13:24

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Feb 9, 2026

Boshen mentioned this pull request Feb 10, 2026

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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feat(minifier): local traverse ctx and generated minifier traverse#19106

feat(minifier): local traverse ctx and generated minifier traverse#19106
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