'use strick';

var aws = require('aws-sdk')
aws.config.update({region:'ap-northeast-1'})

class Users {

    constructor() {
        this.table = 'Users'
        this.dynamodb = new aws.DynamoDB()
    }

    getData(email) {
        let params = {
            TableName: this.table,
            Key      : { 'email': {'S':email} }
        }

        return this.dynamodb.getItem(params).promise()
    }
}
// module.exports = Users // ← this will be success.
module.exports = new Users(); // ← this will be failure.

'use strict';

var aws = require('aws-sdk-mock'),
    users = require('./user'),
    chai = require('chai'),
    path = require('path'),
    should = chai.should(),
    input = 'test@gmail.com',
    usersObj;

aws.setSDK(path.resolve('node_modules/aws-sdk'));

describe('All Tests', function () {
    // this.timeout(0);
    beforeEach(function () {
        aws.mock('DynamoDB', 'getItem', function (params, callback) {
            callback(null, {Item: {email: params.Key.email.S}});
        });

        // usersObj = new users(); ← this will be success.
        usersObj = users; // ← this will be failure.
    });

    it('getData', function (done) {
        usersObj.getData(input).then(function (res) {

            console.log(res);

            res.Item.email.should.equal(input);
            done();
        });
    });
});