unbash: Fast Bash Parser

unbash is a fast, zero-dependency library written in TypeScript for parsing Bash scripts into a structured Abstract Syntax Tree (AST). Currently stable at version 2.2.0, it differentiates itself by offering a pure JavaScript/TypeScript implementation without WASM or native bindings, providing a fully typed API, and delivering high performance, often outperforming alternatives by a significant margin. Its release cadence follows a typical Semantic Versioning approach, with updates for features and bug fixes. Key differentiators include its AST-centric output (unlike CST-focused parsers), tolerant parsing that collects errors rather than throwing exceptions, and built-in support for advanced Bash syntax such as process substitutions, coproc, `[[ ]]` test expressions, `(( ))` arithmetic evaluations, and extglob. It is designed for environments requiring a lightweight, synchronous parsing solution. While it excels at AST generation and speed, it does not offer incremental parsing, full token preservation for CSTs, or multi-shell dialect support (e.g., pure POSIX sh), features found in libraries like tree-sitter-bash or sh-syntax. It requires Node.js v14 or higher and maintains a small bundle size (13KB gzipped).