tsval

tsval is a command-line tool designed for validating JSON or YAML data against a provided TypeScript schema. It leverages the power of TypeScript's type system to ensure that data conforms to a specific structure and set of rules. The tool works by taking a schema file written in TypeScript, compiling it into a JavaScript validation function, and then using this function to check input JSON or YAML data.

The primary use case for tsval is in scenarios where data integrity is critical, such as API request/response validation, configuration file parsing, or inter-service communication. By defining data structures using familiar TypeScript syntax, developers can benefit from type safety and autocompletion during schema definition. The validation process is performed at runtime, catching deviations from the defined schema before they can cause issues in an application.

tsval supports various data types and validation rules, including primitives, arrays, objects, unions, intersections, and custom types. It aims to provide a developer-friendly experience by integrating seamlessly into existing TypeScript development workflows. The tool can be particularly useful for projects that already utilize TypeScript, as it avoids the need to learn a separate validation language.