Open Source TypeScript Linters

Vizualize API changes to improve the quality of reviews. Test API changes to ensure nothing bad slips through. OpenAPI diffs are difficult to read. Because these files contain references, small changes can have a large effect on your API. Linters can not check for backward compatibility or enforce versioning and deprecation policies. Optic adds a visual changelog to every Pull Request that makes it easy to see exactly what API changes have been proposed. Optic tests each set of API changes in CI, making it more powerful than a linter. Our built-in checks will help any team ship a more reliable API. OpenAPI diffs are very difficult to review, comprehend and give feedback on. Optic’s changelogs are easy to understand allowing anyone (even non-developers) to participate in review. Optic goes beyond linting OpenAPI, it lets you write test about each set of API changes. We also make it easy to share your API standards.

Converts your TSLint configuration to the closest reasonable ESLint equivalent. The tslint-to-eslint-config command reads in any existing linter, TypeScript, and package configuration files, then creates an .eslintrc.js result based on them. For any TSLint rules with corresponding ESLint equivalents, those equivalents will be used in the new configuration. TSLint rules without ESLint equivalents will be wrapped with eslint-plugin-tslint. If passed without arguments, respects the excludes, files, and includes in your TypeScript configuration.

commitlint checks if your commit messages meet the conventional commit format. commitlint helps your team adhere to a commit convention. By supporting npm-installed configurations it makes sharing of commit conventions easy. We're not a sponsored OSS project. Therefore we can't promise that we will release patch versions for older releases in a timely manner. If you are stuck on an older version and need a security patch we're happy if you can provide a PR. If something in between fails (like a new packages was added and needs to be published for the first time but you forgot) you can use lerna publish from-package to publish anythign that has not been published yet. We identify ease of adoption and developer experience as fields where there is room and need for improvement. The items on the roadmap should enhance commitlint regarding those aspects.

gts is Google's TypeScript style guide, and the configuration for our formatter, linter, and automatic code fixer. No lint rules to edit, no configuration to update, no more bike shedding over syntax. No configuration. The easiest way to enforce consistent style in your project. Just drop it in. Automatically format code. Just run gts fix and say goodbye to messy or inconsistent code. Catch style issues & programmer errors early. Save precious code review time by eliminating back-and-forth between reviewer & contributor. Opinionated, but not to a fault. We recommend you use the default configuration, but if you need to customize compiler or linter config, you can. Under the covers, we use eslint to enforce the style guide and provide automated fixes, and prettier to re-format code.

Ruff Visual Studio Code is an official Visual Studio Code extension that integrates the Ruff Python linter and formatter directly into the development environment, enabling developers to maintain high code quality with minimal configuration. It provides real-time linting and formatting feedback as developers write code, helping catch errors, enforce style guidelines, and automatically fix issues where possible. The extension is built on top of Ruff’s high-performance Rust-based engine, which is significantly faster than traditional Python linting tools, allowing near-instant feedback even on large codebases. It supports both linting and formatting workflows, consolidating the functionality of multiple tools such as Flake8, Black, and isort into a single unified interface.

Ultracite is a highly opinionated, zero-configuration linting and formatting preset designed primarily for modern JavaScript/TypeScript codebases. It is built on top of the Biome toolchain (written in Rust) and aims to deliver sub-second performance so that formatting and linting feel seamless, even on large projects. Because it comes pre-configured with sensible defaults for frameworks like React and Next.js, developers can adopt it with minimal setup—simply run npx ultracite init and start coding. The project emphasizes type-safety and best practices, enforcing stricter rules out of the box so that unsafe or sloppy patterns are discouraged. It also positions itself as “AI-ready,” meaning it’s designed to integrate smoothly into workflows where AI code generation (e.g., from Copilot, Claude Code, etc) is involved, ensuring consistent style across team-written and machine-written code.

Monorepo for all the tooling which enables ESLint to lint Angular projects. Follow the latest Getting Started guide on angular.io in order to install the Angular CLI. Create a new Angular CLI workspace in the normal way, optionally using any of the supported command line arguments and following the interactive prompts. As well as installing all relevant dependencies, the ng add command will automatically detect that you have a workspace with a single project in it, which does not have a linter configured yet. It can therefore go ahead and wire everything up for you!