What is AJV schema validation and how does it work?

What is AJV schema validation and how does it work?

AJV (Another JSON Schema Validator) is a JavaScript library used to validate JSON objects against JSON Schema definitions. It ensures that the data structure adheres to specified rules.

Can you give me an example of how to use AJV for validation?

Sure! First, you need to install AJV using npm. Then, you can define a schema and validate a JSON object against it. Here's a simple example:

const Ajv = require('ajv');
const ajv = new Ajv();

const schema = {
  type: 'object',
  properties: {
    name: { type: 'string' },
    age: { type: 'integer', minimum: 0 }
  },
  required: ['name', 'age']
};

const validate = ajv.compile(schema);
const data = { name: 'John', age: 30 };
const valid = validate(data);

if (!valid) console.log(validate.errors);
else console.log('Valid data!');

What are some common errors that can occur during validation?

Common errors include type mismatches (e.g., expecting a string but receiving a number), missing required properties, and values that do not meet specified constraints (like minimum or maximum values). You can access these errors through validate.errors.