wmt-marketplace-auth/src/lib/headers.ts

Generate the authentication headers required by Walmart Marketplace API.

/**
 * WM_SVC Authentication header namespace.
 */
export interface WMService {
  /**
   * Walmart Service Name.
   *
   * Header WM_SVC.NAME.
   */
  Name: string;
}

/**
 * WM_QOS Authentication header namespace.
 */
export interface WMQOS {
  /**
   * A unique ID to correlate a vendor's calls with the Walmart system.
   *
   * Header WM_QOS.CORRELATION_ID.
   */
  CorrelationId: string;
}

/**
 * WM_SEC Authentication header namespace.
 */
export interface WMSecurity {
  /**
   * The short-lived token, (which expires after 15 minutes), receiving after
   * using the Token API.
   *
   * Header WM_SEC.ACCESS_TOKEN.
   */
  AccessToken: string;
}

/**
 * Walmart authentication headers. Use the custom class to set custom values to the
 * headers before adding to the request.
 *
 * @see {@link https://developer.walmart.com/#/apicenter/marketPlace/latest#apiAuthentication}
 */
export class Custom {
  /**
   * WM_SVC Authentication headers.
   */
  WMService: WMService;
  /**
   * WM_QOS Authentication headers.
   */
  WMQOS: WMQOS;
  /**
   * WM_SEC Authentication headers.
   *
   */
  WMSecurity: WMSecurity;
  /**
   * The desired returned data format of the response. May override the default to
   * 'application/xml' if an XML response is preferred instead of JSON.
   */
  Accept: string;
  /**
   * The data format used in the request. May override the default to
   * 'application/xml' if an XML response is preferred instead of JSON.
   */
  ContentType: string;

  constructor() {
    this.WMQOS = { CorrelationId: uuid() };
    this.WMService = { Name: 'Walmart Marketplace' };
    this.Accept = 'application/json';
    this.ContentType = 'application/json';
  }

  /**
   * Set the vendor's Correlation ID.
   *
   * @param correlationId A unique ID to correlate a vendor's calls with the Walmart
   *                      system.
   */
  setCorrelationId(correlationId: string): void {
    this.WMQOS = { CorrelationId: correlationId };
  }
}

/**
 * The Token API request headers compiled according to the API specs.
 */
export interface TokenRequestHeaders {
  'WM_SVC.NAME': string;
  'WM_QOS.CORRELATION_ID': string;
  'Authorization': string;
  'Accept': string;
  'Content-Type': string;
}

/**
 * The standard request headers including the granted access token.
 */
export interface TokenHeaders extends TokenRequestHeaders {
  'WM_SEC.ACCESS_TOKEN': string;
}

export interface Credentials {
  /**
   * The API ClientID, provided by Walmart.
   */
  ClientID: string;
  /**
   * The API ClientSecret, provided by Walmart.
   */
  ClientSecret: string;
}

export interface TokenResponse {
  'access_token': string;
  'token_type': string;
  'expires_in': number;
}

export function getTokenRequestHeaders(custom: Custom, credentials: Credentials): TokenRequestHeaders {
  let headers: TokenRequestHeaders = {
    'WM_SVC.NAME': custom.WMService.Name,
    'WM_QOS.CORRELATION_ID': custom.WMQOS.CorrelationId,
    'Authorization': 'Basic ' + Buffer.from(credentials.ClientID + ':' + credentials.ClientSecret).toString('base64'),
    'Accept': custom.Accept,
    'Content-Type': 'application/x-www-form-urlencoded'
  }
  return headers;
}

export function uuid() {
  return "00000000-0000-4000-8000-000000000000".replace(/0/g, function () { return (0 | Math.random() * 16).toString(16) })
}