Fastify request/response validations

request-response-validation.js

/* eslint-disable no-console */
const responseValidation = require('@fastify/response-validation');
const Ajv = require('ajv');
const addFormats = require('ajv-formats');
const fastify = require('fastify');
const { S } = require('fluent-json-schema');

(async () => {
  const app = fastify();

  const ajv = new Ajv();
  addFormats(ajv);
  app.setValidatorCompiler(({ schema }) => ajv.compile(schema));

  await app.register(responseValidation);

  app.post('/validate', {
    schema: {
      body: S.object()
        .additionalProperties(false)
        .prop('name', S.string())
        .prop('age', S.number())
        .required(['name', 'age'])
        .valueOf(),
      response: {
        200: S.object()
          .additionalProperties(false)
          .prop('missing', S.string())
          .prop('headers', S.object()
            .additionalProperties(true))
          .prop('body', S.object()
            .additionalProperties(true))
          .required(['missing', 'headers', 'body'])
          .valueOf(),
      },
    },
  }, async (req, reply) => reply.send({ headers: req.headers, body: req.body }));

  const responseHandler = (error, { statusCode, statusMessage, headers, json }) => {
    if (error) console.error({ error });
    console.log({ statusCode, statusMessage, headers, body: json() });
  };

  app.inject({ method: 'POST', url: '/validate', payload: { name: 1.5, age: '20' } }, responseHandler);
  app.inject({ method: 'POST', url: '/validate', payload: { name: 'John', age: 20 } }, responseHandler);
})();