index.js

const AWS = require('aws-sdk');
const dynamoDb = new AWS.DynamoDB.DocumentClient();
const uuidv4 = require('uuid/v4');
const processResponse = require('./process-response.js');
const TABLE_NAME = process.env.TABLE_NAME;
const IS_CORS = process.env.IS_CORS;
const PRIMARY_KEY = process.env.PRIMARY_KEY;

exports.handler = (event) => {
  if (event.httpMethod === 'OPTIONS') {
    return Promise.resolve(processResponse(IS_CORS));
  }
  if (!event.body) {
    return Promise.resolve(processResponse(IS_CORS, 'invalid', 400));
  }
  let item = JSON.parse(event.body);
  item[PRIMARY_KEY] = uuidv4();
  let params = {
    TableName: TABLE_NAME,
    Item: item
  }
  return dynamoDb.put(params)
    .promise()
    .then(() => (processResponse(IS_CORS)))
    .catch(dbError => {
      let errorResponse = `Error: Execution update, caused a Dynamodb error, please look at your logs.`;
      if (dbError.code === 'ValidationException') {
        if (dbError.message.includes('reserved keyword')) errorResponse = `Error: You're using AWS reserved keywords as attributes`;
      }
      console.log(dbError);
      return processResponse(IS_CORS, errorResponse, 500);
    });
};