AJV validator to use with react-final-form

ajvValidator.js

import Ajv from 'ajv/dist/ajv.min';
import AddIf from 'ajv-keywords/keywords/if';

const makeValidator = (schema) => {
  const ajv = new Ajv({ allErrors: true, coerceTypes: true });

  // Add If-then-else from ajv-keywords package
  AddIf(ajv);

  // Add custom keyword
  ajv.addKeyword('customKeyword', {
    validate: (aSchema, value) => customValidationFunction(value),
    errors: false,
  });

  const validator = ajv.compile(schema);

  // Return a redux-form compatible validation function
  return (values) => {
    const errors = {};

    if (values.toJS) {
      validator(values.toJS());
      if (validator.errors) {
        validator.errors.forEach((obj) => {
          // Massage ajv errors to the { 'fieldName': 'errorMessage' } format expected by redux-form
          if (obj.keyword === 'required') {
            errors[obj.params.missingProperty] = obj.message;
          } else {
            errors[obj.dataPath.replace('.', '')] = obj.message;
          }
        });
      }
    }

    return errors;
  };
}

This REALLY helped with integrating into the clusterfck bullsht that is react-admin, which uses react-final-form under the hood. You're a goddamn saint.