@ibm-cloud/openapi-ruleset/src/functions/precondition-header.js

Spectral ruleset for validating IBM Cloud services

/**
 * Copyright 2017 - 2023 IBM Corporation.
 * SPDX-License-Identifier: Apache2.0
 */

const { LoggerFactory } = require('../utils');

let ruleId;
let logger;

module.exports = function (operation, _opts, context) {
  if (!logger) {
    ruleId = context.rule.name;
    logger = LoggerFactory.getInstance().getLogger(ruleId);
  }
  return preconditionHeader(operation, context.path);
};

/**
 * This function checks if an operation contains a 412 response it must support at least one conditional header.
 * @param {*} operation an operation within the API definition
 * @param {*} path the array of path segments indicating the "location" of the operation within the API definition
 * @returns an array containing the violations found or [] if no violations
 */
function preconditionHeader(operation, path) {
  if (!operation.responses) {
    return [];
  }

  logger.debug(
    `${ruleId}: checking operation for pre-condition headers at location: ${path.join(
      '.'
    )}`
  );

  if (Object.keys(operation.responses).includes('412')) {
    const conditionalHeaders = [
      'If-Match',
      'If-None-Match',
      'If-Modified-Since',
      'If-Unmodified-Since',
    ];
    let found = false;
    for (const k in operation.parameters) {
      if (conditionalHeaders.includes(operation.parameters[k].name)) {
        found = true;
        logger.debug(
          `${ruleId}: found pre-condition header param'${operation.parameters[k].name}'`
        );
      }
    }

    if (!found) {
      logger.debug(`${ruleId}: no pre-condition header params found!`);
      return [
        {
          message:
            'An operation that returns a 412 status code must support at least one conditional header',
          path: [...path, 'responses'],
        },
      ];
    }
  }

  return [];
}