ESLint

Rust-native static analysis for JavaScript and TypeScript. Maps a repository as one dependency graph to find unused code and structural problems across file boundaries. Runs from the CLI or GitHub Actions, with VS Code, LSP, MCP, and Node API integrations.

Pluggable and configurable code transformer with built-in eslint, babel plugins support for js, jsx typescript, flow, markdown, yaml and json.

Dependency analysis and optimization toolkit for modern JavaScript and TypeScript projects. Trace imports, identify circular dependencies, find unused code, clean node modules.

ast-grep is a powerful tool designed for managing code at scale using Abstract Syntax Trees (AST). Think of it as a hybrid of grep, eslint, and codemod, with the ability to search, lint, and rewrite code based on its structure rather than plain text. It supports multiple languages and is designed to be extensible, allowing you to register custom languages.

A linter and formatter to help you to improve copywriting, correct spaces, words, punctuations between CJK (Chinese, Japanese, Korean).

Open-Source static code analysis tool to discover, filter and prioritize security risks and vulnerabilities leading to sensitive data exposures (PII, PHI, PD). Highly configurable and easily extensible, built for security and engineering teams.

A language-agnostic linter that keeps code, documentation, and configuration in sync and enforces strict formatting and validation rules.

Ecosystem for structural matching JavaScript and TypeScript code. Offers search tool that understands code structure. Available as CLI tool and Visual Studio Code extension. It helps to search code faster and more accurately making you workflow more effective. Soon it will offer ESLint plugin to create your own rules in minutes to help with assuring codebase quality.

Copy/paste detector for programming source code. Finds duplicated blocks in 200+ file formats — JavaScript, TypeScript, Python, Java, C#, C/C++, Go, Rust, PHP, Ruby and more — using token-based detection. Supports configurable thresholds and ignore patterns, git blame integration, and reporters for console, HTML, JSON, Markdown, SARIF and badges. Runs via CLI, in CI pipelines, or as a library; bundled by MegaLinter and Codacy.

Mega-Linter can handle any type of project thanks to its 70+ embedded Linters, its advanced reporting, runnable on any CI system or locally, with assisted installation and configuration, able to apply formatting and fixes

Semantic version control CLI that provides entity-level diffs, blame, and impact analysis on top of git. Uses tree-sitter to parse 26 languages and builds a cross-file dependency graph with structural hashing. Commands include sem diff, sem blame, sem graph, and sem impact for blast-radius analysis of code changes.

A fast, open-source, static analysis tool for finding bugs and enforcing code standards at editor, commit, and CI time. Its rules look like the code you already write; no abstract syntax trees or regex wrestling. Supports 17+ languages.

Entity-level semantic merge driver for git. Resolves false conflicts that line-based merge produces when independent changes touch the same file. Parses functions and classes via tree-sitter, matches by name, and merges at the entity level. Benchmarked at 100% clean merges vs git's 48% on a 31-scenario suite.