💡 Learn more about JSON Schema at json-schema.org.
Because after using it for years, I came to acknowledge that the current de facto standard library for JSON schema validation in JavaScript apps -- AJV -- is clunky. I thought, "how hard could it be?" Two days later, here we are. As it turns out, not that hard.
I primarily use JSON Schema validation for HTTP requests. For each endpoint, I model the query parameters, path parameters, and request body I expect as a JSON Schema, and I short-circuit processing when this validation fails. It's one of the many stages in a multi-stage request processing pipeline.
- lightweight and minimal -- zero dependencies
- readable implementation -- learn from the source code
- readable errors -- easy to see what failed and why
- comprehensive test suite -- 100% code coverage
- idiomatic usage -- failed validation throws an error
- concurrency-friendly -- tightly scoped for massively parallel usage
- fast -- highly tuned for validation performance
- standard compliant -- IETF draft-bhutton-json-schema-validation-01 (2022-06-16)
Install VSJ just like you would any other npm package:
npm install vsjimport { createValidator } from 'vsj';
const validate = createValidator({ type: 'number' });
// throws a validation error
validate('hello world');
// does not throw an error
validate(123);