To measure coverage of your validation code use ajv v7 to compile schemas to standalone validation code - it is now fully imlemented/supported - and use any testing framework you prefer - no need to use this package.
Instrument validation code generated by Ajv to measure test coverage of your schemas
npm i ajv-istanbul --save-dev
ajv-istanbul requires using Ajv version >= 5.0.1-beta.
var Ajv = require('ajv');
var ajv = new Ajv;
require('ajv-istanbul')(ajv);
See tests for example how to collect coverage and generate reports.