You could use jest.mock(moduleName, factory, options) to mock aws-sdk module manually. E.g. handler.js: const aws = require('aws-sdk'); const dynamoDb = new aws.DynamoDB.DocumentClient(); const promisify = (foo) => new Promise((resolve, reject) => { foo((error, result) => { if (error) { reject(error); } else { resolve(result); } }); }); const getUser = (userId) => promisify((callback) => dynamoD..