DSH-Syntax-Checker

AI models frequently emit code with subtle syntax problems-mismatched brackets, zero-width spaces, BOM markers, broken Python indentation-that force developers to comb through generated output line by line. DSH Syntax Checker turns syntax validation into a tool the model can call directly, catching and fixing issues at the point of generation instead of after the fact.

The engine covers JavaScript, TypeScript, YAML, and Python: JS/TS/YAML are parsed by web-tree-sitter (WASM grammars) and Python by Ruff. It detects unmatched brackets (brackets inside string literals are automatically excluded), invisible characters (zero-width spaces, BOM, bidirectional control marks), syntax errors, trailing whitespace, duplicate YAML keys, and Tab indentation. Auto-fix is powered by Ruff check --fix, and an edit applier maps line/column positions back to source offsets for precise write-back. The same engine ships in three forms: a DSH Cordis plugin exposing a syntax_check tool to the model and a syntaxChecker service to sibling plugins, a standalone Fastify HTTP service with OpenAPI documentation, or a createSyntaxChecker() library for direct embedding in any Node.js upstream system.

It is aimed at DSH ecosystem developers who want a code-quality gatekeeper in front of their AI assistant, teams running production services that need a lightweight multi-language lint-and-fix endpoint, and engineers building automated quality pipelines who would rather call one well-tested module than wire up Tree-sitter and Ruff themselves.