Files
Dunqing 8ab883afaa fix(codegen): preserve property key annotations (#25766)
`@__KEY__` and `#__KEY__` are currently treated as normal comments. Codegen can drop them before a later property-mangling pass. The property may then be renamed while the annotated string keeps its old name.

This classifies the marker as a property-key annotation. Codegen keeps it next to string and no-substitution template literals when annotation comments are enabled, and the property mangler reads that classification instead of scanning source text. Final output still follows the normal comment options, so whitespace-minified or annotation-disabled output removes the marker.

## Example

Input:

```js
const object = { _field: 1 };
const key = /* #__KEY__ */ "_field";
object[key];
```

Before, an intermediate codegen pass could remove the marker:

```js
const object = { _field: 1 };
const key = "_field";
object[key];
```

After, the marker survives for the later property-mangling pass.

Verified with the affected crate suites, `just minsize`, workspace lint, docs, AST generation, and independent review. `just ready` is only blocked locally by existing Node-version and terminal-color snapshot differences.

Implemented with AI assistance (OpenAI Codex). I reviewed and understand the changes and remain responsible for this contribution under the repository AI usage policy.
2026-08-17 09:23:04 +00:00
..
…

Oxc Parser

High-performance JavaScript and TypeScript parser with comprehensive language support.

Overview

This crate provides a fast, spec-compliant parser for JavaScript and TypeScript that produces a complete Abstract Syntax Tree (AST). It supports all modern language features including JSX, TSX, and the latest ECMAScript proposals.

Key Features

  • Complete language support: JavaScript, TypeScript, JSX, and TSX
  • Latest ECMAScript: All stable ECMAScript features plus stage 3+ proposals
  • High performance: Significantly faster than traditional parsers
  • Error recovery: Continues parsing after errors to provide complete AST
  • Comprehensive AST: Detailed node information with accurate source positions

Architecture

Parser Design

  • Recursive descent: Traditional recursive descent parser architecture
  • Error recovery: Sophisticated error recovery for IDE-friendly parsing
  • Memory efficient: Uses arena allocation for optimal performance
  • Streaming: Processes source text in a single pass

Language Support

  • JavaScript: Full ECMAScript 2024+ support
  • TypeScript: Complete TypeScript syntax including decorators
  • JSX/TSX: React JSX and TypeScript JSX syntax
  • Proposals: Stage 3 decorators and other advancing proposals

AST Structure

The parser produces an AST that closely follows ECMAScript specifications:

  • Accurate positions: Every node has precise source location information
  • Complete information: Preserves all syntactic details including trivia
  • Type-safe: Leverages Rust's type system for correctness
  • Visitor-friendly: Designed for easy traversal and transformation

The parser is designed as the foundation for all other oxc tools, providing the high-quality AST needed for analysis, transformation, and code generation.