#Validator class overview

Validator is an encapsulation of AJV, providing compilation caching, error formatting, custom keywords and batch validation capabilities.

import { Validator, s } from 'schema-dsl/pure';
const validator = new Validator();
const schema = s({ email: 'email!' });
console.log(validator.validate(schema, { email: 'test@example.com' }));

#Cache configuration

Validator The constructor supports two cache writing methods:

new Validator({ cache: true }); // Use default cache configuration
new Validator({ cache: false }); // Turn off caching

new Validator({
  cache: {
	enabled: true,
	maxSize: 500,
	ttl: 60 * 60 * 1000
  }
});

The cache is owned by the Validator instance. In a server, create the instance during application startup and reuse it:

const validator = new Validator({ cache: { maxSize: 500 } });

app.post('/users', (req, res) => {
  res.json(validator.validate(userSchema, req.body));
});

Creating new Validator() inside every request handler is usually not a retained-memory leak by itself, but it throws away the previous AJV instance and compile cache. That pattern increases allocation, garbage collection and schema compilation work, so it should only be used for isolated one-off validation paths where the instance is not stored.

The cache only helps when schema structures repeat. If each request produces a never-before-seen dynamic schema, cache entries will churn and the application still pays the compile cost for each miss. Bound the number of dynamic schema shapes, or validate them in an isolated short-lived path.

If you wish to pass in a DSL object directly (e.g. validate({ email: 'email!' }, data)), please use the top-level convenience functions validate() / validateAsync(); Validator instance methods are still recommended to receive the conversion results of standard JSON Schema or s({...}).

Related methods: compile(), validate(), validateAsync(), validateBatch(), addKeyword(), addFormat().

#Corresponding sample file

Example entry: validator.ts Description: Covers new Validator()’s common configuration, single validation, compilation cache hits and validateBatch() reuse paths.