docs(es/transformer): Add comprehensive oxc transform porting guide
This guide provides a detailed analysis of all transforms implemented in
oxc_transformer and their porting priorities to SWC's VisitMutHook architecture.
## Key Contents
- **Transform Inventory**: Complete list of all oxc transforms organized by
ECMAScript version (ES2015-ES2026), TypeScript, React/JSX, decorators, and regex
- **Implementation Details**: For each transform:
- Babel equivalent plugin name
- Complexity assessment
- Key AST nodes operated on
- Dependencies and helper functions
- Implementation approach (enter/exit hooks)
- Current status in SWC
- **Porting Priority**: 8 phases prioritizing transforms by:
- Foundation utilities first
- Frequency of use
- Dependencies between transforms
- Complexity vs impact balance
- **Implementation Patterns**: Detailed patterns for:
- Hook usage (entry vs exit)
- Mapping oxc's Traverse trait to SWC's VisitMutHook
- Common transform patterns (syntax rewrite, side effects, multi-phase, etc.)
- Helper function injection
- Scope-aware transformations
- **Testing Strategy**: Guidance on:
- Babel conformance test integration
- Unit, integration, and snapshot testing
- Performance benchmarking
- Real-world validation
- **Architecture Comparison**: Detailed comparison of oxc and SWC architectures
## Transforms Analyzed
Documented 60+ transforms across:
- ES2015 (15 transforms)
- ES2016-ES2022 (20+ transforms)
- TypeScript (6 transforms)
- React/JSX (5 transforms)
- Decorators, regex, and utilities
Follow-up to #11293 which established the foundational swc_ecma_transformer crate.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>