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oxc-guard
894c8f9cd8
### 💥 BREAKING CHANGES -a31567aallocator: [**BREAKING**] Make `Allocator::cursor_ptr` and `data_end_ptr` private (#26081) (overlookmotel) ### 🚀 Features -784e9faminifier: Invert `!0` and `!1` in place for boolean context to `1` and `0` (#26050) (Armano) -1e902ccminifier: Expand fold leading assignments into the var decl (#26142) (Armano) -3ed4f6aminifier: Expand de morgan's optimization to allow move of `!` (#25930) (Armano) -5672585parser: Attach all comments to nodes (#25944) (camc314) ### 🐛 Bug Fixes -4adfb4csemantic: Validate chained continue labels (#26157) (camc314) -b874f48ecmascript: `Math.round` only exact half ties (#26150) (camc314) -a625378minifier: Coerce omitted `indexOf` search argument (#26149) (camc314) -dc7398becmascript: Trim trailing whitespace in string to number (#26148) (camc314) -243b685transformer/object-rest: Lower multiple declarators correctly (#26147) (camc314) -dc09a3aparser: Avoid panic on escaped string export names (#26146) (camc314) -e412cf2linter: Clamp invalid JS plugin locations (#26144) (camc314) -c3dedc9semantic: Skip function body bindings in parameters (#26099) (Dunqing) -e74de61transform-react: Match Babel diagnostic reporting (#26128) (Boshen) -d5163d0parser: Correctly classify unapplied pure annotations (#26084) (camc314) -8531b9blinter/plugins: Alter method for obtaining mutable `Program` when sending AST to JS plugins (#26077) (overlookmotel) -9b51658regular_expression: Allow oversized decimal escape for Annex B (#26070) (leaysgur) -c8de4dfregular_expression: Reject oversized backreferences (#26055) (camc314) ### ⚡ Performance -ac4785adiagnostics: Use fixed ANSI styles (#26130) (Boshen) -07a0793packages/codegen: Flatten output in chunks (#26109) (overlookmotel) -487427apackages/codegen: Faster string flattening (#26108) (overlookmotel) -7785583packages/codegen: Ensure indent strings are flattened (#26107) (overlookmotel) -0dd4db3packages/codegen: Store mapping positions in an `Int32Array` (#26085) (overlookmotel)
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.