AWS Lambda code to add a default warehouse to a commercetools platform API request

ctp-add-default-warehouse-in-lambda.js

'use strict';

const https = require('https');
exports.handler = (event, context, callback) => {
  const buffer = Buffer.from(event.body, 'base64');
  let requestBody = JSON.parse(buffer.toString());
  requestBody = setDefaultSupplyChannel(requestBody);
  let requestBodyAsString = JSON.stringify(requestBody);
  
  const options = {
    hostname: 'api.sphere.io',
    port: 443,
    path: '/' + event.stageVariables.project_key + event.path,
    method: event.httpMethod,
    headers: event.headers
  };
  options.headers.Host = 'api.sphere.io';
  const req = https.request(options, (res) => {
    var chunks = [];
    res.on('data', (chunk) => chunks.push(chunk));
    res.on('end', () => {
      var buffer = Buffer.concat(chunks);
      var responseBody = buffer.toString('base64');
      callback(null, {
        "body": responseBody,
        "isBase64Encoded": true,
        "statusCode": res.statusCode,
        "headers": res.headers
      });
    });
  });
  req.on('error', callback);
  req.write(requestBodyAsString);
  req.end();
};

const setDefaultSupplyChannel = (requestBody) => {
  requestBody.actions = requestBody.actions.map((action) => {
    if (action.action == 'addLineItem') {
      // CHECK #1: In doubt, deliver from the san francisco store.
      if (typeof action.supplyChannel != 'Object') {
        action.supplyChannel = {
          'typeId' : 'channel',
          'id' : 'e852da8d-e1b3-4628-9ac0-e0d3c4fb8523'
        };
        console.log("added channel to line item")
      }
    }
    return action;
  });
  return requestBody;
};