vwo-fme-node-sdk/lib/packages/network-layer/handlers/RequestHandler.ts

VWO Node/JavaScript SDK for Feature Management and Experimentation

/**
 * Copyright 2024-2025 Wingify Software Pvt. Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { dynamic } from '../../../types/Common';
import { GlobalRequestModel } from '../models/GlobalRequestModel';
import { RequestModel } from '../models/RequestModel';

/**
 * A class responsible for creating and modifying request models based on a global configuration.
 */
export class RequestHandler {
  /**
   * Creates a new request by merging properties from a base request and a configuration model.
   * If both the request URL and the base URL from the configuration are missing, it returns null.
   * Otherwise, it merges the properties from the configuration into the request if they are not already set.
   *
   * @param {RequestModel} request - The initial request model.
   * @param {GlobalRequestModel} config - The global request configuration model.
   * @returns {RequestModel} The merged request model or null if both URLs are missing.
   */
  createRequest(request: RequestModel, config: GlobalRequestModel): RequestModel {
    // Check if both the request URL and the configuration base URL are missing
    if (
      (config.getBaseUrl() === null || config.getBaseUrl() === undefined) &&
      (request.getUrl() === null || request.getUrl() === undefined)
    ) {
      return null; // Return null if no URL is specified
    }
    // Set the request URL, defaulting to the configuration base URL if not set
    request.setUrl(request.getUrl() || config.getBaseUrl());
    // Set the request timeout, defaulting to the configuration timeout if not set
    request.setTimeout(request.getTimeout() || config.getTimeout());
    // Set the request body, defaulting to the configuration body if not set
    request.setBody(request.getBody() || config.getBody());
    // Set the request headers, defaulting to the configuration headers if not set
    request.setHeaders(request.getHeaders() || config.getHeaders());
    // Initialize request query parameters, defaulting to an empty object if not set
    const requestQueryParams: Record<string, dynamic> = request.getQuery() || {};
    // Initialize configuration query parameters, defaulting to an empty object if not set
    const configQueryParams: Record<string, dynamic> = config.getQuery() || {};

    // Merge configuration query parameters into the request query parameters if they don't exist
    for (const queryKey in configQueryParams) {
      if (!Object.prototype.hasOwnProperty.call(requestQueryParams, queryKey)) {
        requestQueryParams[queryKey] = configQueryParams[queryKey];
      }
    }
    // Set the merged query parameters back to the request
    request.setQuery(requestQueryParams);
    return request; // Return the modified request
  }
}