mirror of https://github.com/oxc-project/oxc.git synced 2026-09-14 19:36:11 +08:00

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History

oxc-guard 60fa13878c release(crates): oxc v0.149.0 (#26397 )

### 💥 BREAKING CHANGES

- 66744f0 parser: [**BREAKING**] Rename `panicked` to `fatal_error` in `ParserReturn` (#26382) (overlookmotel)
- 2c9a947 parser: [**BREAKING**] Reduce `MAX_LEN` to 256 bytes below `u32::MAX` (#26352) (overlookmotel)

### 🚀 Features

- 32bdc5b allocator: Construct `ArenaHashSet` with any `Default` hasher (#26372) (Dunqing)
- a17de58 minifier: Process of return/throw in non last position and fix async * inlining (#26214) (Armano)
- bfb4c57 parser: Distinguish unapplied no-side-effects comments (#26120) (碳苯 Carbon)
- 1d9b9d3 ast: Add `GetNodeId` trait (#26145) (camc314)

### 🐛 Bug Fixes

- b156333 codegen: Order accessibility before abstract on accessors (#26392) (camc314)
- 116c8b8 transformer/class-properties: Keep private methods in class-expression scope (#26308) (Changsu Seong)
- 1400a0f parser: Require a string source after `export ... from` (#26389) (camc314)
- 2da73b7 codegen: Print matching quoted import names as identifiers (#26386) (camc314)
- 0a81d29 codegen: Preserve private-in left operand precedence (#26383) (camc314)
- 9a02337 parser: Correctly round large nondecimal literals (#26379) (camc314)
- 3d95477 transformer: Gate async-only rewrites by owning transform (#26326) (Dunqing)
- f45a9ee transformer: Limit arguments capture to lowered async functions (#26317) (Dunqing)
- 789969f transformer: Gate this capture by owning async transform (#26227) (Dunqing)
- affeb14 minifier: Mangle class private members in Node API (#26118) (碳苯 Carbon)
- 8b35abd semantic: Detect duplicate private class elements (#26361) (camc314)
- 457ed57 semantic: Reject await and yield in rest parameter defaults (#26359) (camc314)
- 4b89c7b semantic: Reject jumps across arrow functions (#26357) (camc314)
- c966aca parser: Do not omit `<` token opening type argument list (#26328) (overlookmotel)
- f07dca5 ast_visit: Add the trimmed prefix length to translation table offsets (#26173) (Bharadwaj Pendyala)
- 3ab9bd1 parser: Do not re-lex template substitution tail after fatal error (#26230) (overlookmotel)
- 07851b9 parser: Fix debug assert failure when lexer error with tokens enabled (#26229) (overlookmotel)
- 00dea7a allocator: Gate `Allocator::data_end_ptr` behind fixed_size feature (#26248) (camc314)
- 853ffab ecmascript: Avoid `charAt` panic on 32-bit (#26244) (camc314)
- 34feccb runtime: Remove stale regenerator exports (#26243) (camc314)

### ⚡ Performance

- 34a242e minifier: Use `Ident` for property mangler (#26334) (sapphi-red)
- 5303f5c minifier: Unify merging of last expression into target sequence (#26264) (Armano)
- 2ca7d29 minifier: Consume nodes in minimize_statements in reverse order (#26258) (Armano)
- d2354b4 mangler: Use `Ident` for variable names to keep (#26333) (sapphi-red)
- 5b3e335 minifier: Use `Ident` instead of `Str` in `KeepVar` (#26332) (sapphi-red)
- 51366fb minifier: Use `IdentHashSet` in `PrivateMemberUsageStack` (#26331) (sapphi-red)
- d19c42a minifier: Merge nested if stmt in place instead of creating dummies (#26351) (Armano)
- 356def6 parser: Shrink annotation comment ranges (#26356) (overlookmotel)
- a5be474 parser: Shave instruction off `parse_jsx_element_name` (#26355) (overlookmotel)
- 9780663 parser: Remove fatal error guard from `parse_jsx_element_name` (#26354) (overlookmotel)
- 766e12f parser: Remove `token` field from `LexerCheckpoint` (#26350) (overlookmotel)

### 📚 Documentation

- d4b4e61 transformer: Document ES2015 target floor (#26378) (Dunqing)
- 67dd054 ast_visit: Correct out-of-date comments on `Utf8ToUtf16` converter (#26285) (overlookmotel)
- a8ed2a7 minifier: Fix stale validation instructions (#26251) (camc314)

2026-09-07 14:29:34 +00:00

src

feat(parser)!: rename panicked to fatal_error in ParserReturn (#26382 )

2026-09-07 09:41:52 +00:00

Cargo.toml

release(crates): oxc v0.149.0 (#26397 )

2026-09-07 14:29:34 +00:00

CHANGELOG.md

release(crates): oxc v0.149.0 (#26397 )

2026-09-07 14:29:34 +00:00

README.md

docs(rust): Add comprehensive README.md documentation for all Rust crates (#12706 )

2025-08-01 18:13:46 +08:00

README.md

Oxc Mangler

Variable name mangling for JavaScript minification.

Overview

This crate provides variable name mangling capabilities for JavaScript minification. It shortens variable names to reduce bundle size while preserving program semantics and ensuring gzip-friendly output.

Key Features

Intelligent mangling: Shortens variable names while avoiding conflicts
Scope-aware: Respects JavaScript scoping rules
Gzip optimization: Generates names that compress well
Configurable: Options to preserve specific names or patterns
Base54 encoding: Efficient character usage for maximum compression

Architecture

Mangling Strategy

Symbol Analysis: Identify all variables and their scopes
Frequency Analysis: Count usage to optimize for common variables
Name Generation: Generate short names using base54 encoding
Conflict Resolution: Ensure no naming conflicts across scopes
Integration: Update symbol table with new names

Base54 Encoding

Uses a character set optimized for JavaScript identifiers:

First character: a-zA-Z_$ (54 options)
Subsequent characters: a-zA-Z0-9_$ (64 options)
Generates shortest possible names: a, b, ..., aa, ab, etc.

Gzip Optimization

The mangling algorithm considers:

Character frequency: Prefer characters that compress well
Repetition patterns: Generate names that create gzip-friendly patterns
Context awareness: Consider surrounding code when choosing names

Integration with Minifier

The mangler works as part of the broader minification pipeline:

Parse: Build AST from source code
Analyze: Perform semantic analysis
Mangle: Shorten variable names
Transform: Apply other minification transforms
Generate: Output minified code

This approach ensures maximum size reduction while maintaining correctness.