stac-node-validator/src/baseValidator.js

STAC Validator for NodeJS

const Test = require('./test');
try {
  // eslint-disable-next-line no-unused-vars -- imported for JSDoc type
  const { STAC } = require('stac-js');
} catch (error) {
  // stac-js is optional
}

class BaseValidator {
  /**
   * Creates a new BaseValidator instance.
   */
  constructor() {}

  /**
   * Customize the ajv JSON Schema validator instance before schemas are compiled.
   *
   * @param {import('ajv').default} ajv
   * @returns {import('ajv').default}
   */
  async createAjv(ajv) {
    return ajv;
  }

  /**
   * Any preprocessing work you want to do on the data.
   *
   * @param {Object} data
   * @param {import('.').Report} report
   * @param {import('.').Config} config
   * @returns {Object}
   */
  async afterLoading(data, report, config) {
    return data;
  }

  /**
   * Bypass the STAC validation, do something different but still return a report.
   *
   * Could be used to validate against a different schema, e.g. OGC API - Records.
   *
   * Return a Report to bypass validation, or null to continue with STAC validation.
   *
   * @param {Object} data
   * @param {import('.').Report} report
   * @param {import('.').Config} config
   * @returns {import('.').Report|null}
   */
  async bypassValidation(data, report, config) {
    return null;
  }

  /**
   * Any custom validation routines you want to run.
   *
   * You can either create a list of errors using the test interface
   * or just throw on the first error.
   *
   * @param {Object|STAC} data STAC object, optionally a stac-js object if the dependency is installed.
   * @param {Test} test
   * @param {import('.').Report} report
   * @param {import('.').Config} config
   * @throws {Error}
   */
  async afterValidation(data, test, report, config) {}

  /**
   * Runs a test function and collects any errors into the report.
   *
   * @param {import('.').Report} report
   * @param {Function} fn - Async function receiving (report, test) as arguments.
   */
  async testFn(report, fn) {
    let errors = [];
    try {
      const test = new Test();
      await fn(report, test);
      errors = test.errors;
    } catch (error) {
      errors = [error];
    } finally {
      report.results.custom = (report.results.custom || []).concat(errors);
      if (errors.length > 0) {
        report.valid = false;
      }
    }
  }
}

module.exports = BaseValidator;