ahmadnassri/httpsnippet

/**
 * @description
 * HTTP code snippet generator to generate raw HTTP/1.1 request strings,
 * in accordance to the RFC 7230 (and RFC 7231) specifications.
 *
 * @author
 * @irvinlim
 *
 * For any questions or issues regarding the generated code snippet, please open an issue mentioning the author.
 */

import { CodeBuilder } from '../../../helpers/code-builder';
import { Client } from '../../targets';

const CRLF = '\r\n';

interface Http11Options {
  absoluteURI?: boolean;
  autoContentLength?: boolean;
  autoHost?: boolean;
}

/**
 * Request follows the request message format in accordance to RFC 7230, Section 3.
 * Each section is prepended with the RFC and section number.
 * See more at https://tools.ietf.org/html/rfc7230#section-3.
 */
export const http11: Client<Http11Options> = {
  info: {
    key: 'http1.1',
    title: 'HTTP/1.1',
    link: 'https://tools.ietf.org/html/rfc7230',
    description: 'HTTP/1.1 request string in accordance with RFC 7230',
  },
  convert: ({ method, fullUrl, uriObj, httpVersion, allHeaders, postData }, options) => {
    const opts = {
      absoluteURI: false,
      autoContentLength: true,
      autoHost: true,
      ...options,
    };

    // RFC 7230 Section 3. Message Format
    // All lines have no indentation, and should be terminated with CRLF.
    const { blank, push, join } = new CodeBuilder({ indent: '', join: CRLF });

    // RFC 7230 Section 5.3. Request Target
    // Determines if the Request-Line should use 'absolute-form' or 'origin-form'.
    // Basically it means whether the "http://domain.com" will prepend the full url.
    const requestUrl = opts.absoluteURI ? fullUrl : uriObj.path;

    // RFC 7230 Section 3.1.1. Request-Line
    push(`${method} ${requestUrl} ${httpVersion}`);

    const headerKeys = Object.keys(allHeaders);
    // RFC 7231 Section 5. Header Fields
    headerKeys.forEach(key => {
      // Capitalize header keys, even though it's not required by the spec.
      const keyCapitalized = key.toLowerCase().replace(/(^|-)(\w)/g, input => input.toUpperCase());
      push(`${keyCapitalized}: ${allHeaders[key]}`);
    });

    // RFC 7230 Section 5.4. Host
    // Automatically set Host header if option is on and on header already exists.
    if (opts.autoHost && !headerKeys.includes('host')) {
      push(`Host: ${uriObj.host}`);
    }

    // RFC 7230 Section 3.3.3. Message Body Length
    // Automatically set Content-Length header if option is on, postData is present and no header already exists.
    if (opts.autoContentLength && postData.text && !headerKeys.includes('content-length')) {
      const length = Buffer.byteLength(postData.text, 'ascii').toString();
      push(`Content-Length: ${length}`);
    }

    // Add extra line after header section.
    blank();

    // Separate header section and message body section.
    const headerSection = join();

    // RFC 7230 Section 3.3. Message Body
    const messageBody = postData.text || '';

    // RFC 7230 Section 3. Message Format
    // Extra CRLF separating the headers from the body.
    return `${headerSection}${CRLF}${messageBody}`;
  },
};