ast_analyser

Dart AST analysis CLI built on tree-sitter.

What it does

Scans Dart source files for null-assertion operator (!) usage and reports locations as structured JSON. Designed to run in CI pipelines as a code quality gate — currently used in production at my employer to enforce null-safety discipline across the codebase.

Tech Stack

• Rust — core language
• tree-sitter — incremental parsing framework for AST construction
• tree-sitter-dart — Dart grammar for tree-sitter
• clap — CLI argument parsing
• walkdir — recursive directory traversal
• serde — JSON serialization of analysis results

Running locally

# Analyse a single file
cargo run -- file -f path/to/file.dart

# Analyse all files in a directory recursively
cargo run -- directory -d path/to/dart/project

# Analyse multiple specific files
cargo run -- files -f file1.dart,file2.dart

Output is JSON with transgression locations, counts, and affected files.

Design Decisions

• tree-sitter over regex: AST-level analysis catches bang operators in all syntactic positions without false positives from comments or strings.
• Structured JSON output: Enables integration with CI tools, editors, and reporting dashboards without parsing human-readable text.
• Subcommand-based CLI: Separate file, files, and directory modes keep each path simple and explicit rather than overloading a single interface.