为什么在包装在exports.handler中时，Lambda上的代码出错？

我正在使用这个casperjs nodejs app：https://github.com/narainsagar/node-casperjs-aws-lambda

我已经让我的代码在本地工作，并在上传到Lambda时，但是我需要将我的代码包装在exports.handler中，这样我就可以从API网关向函数传递数据 . （我已经使用其他未使用此应用程序的函数执行此操作 . ）当我将我的代码放在exports.handler中时，它会失败 . 我已经测试过将事件数据添加到lambda中的测试事件中，我尝试过对其进行硬编码 . 当我的代码在exports.handler中时，两者都失败了 . 为什么exports.handler会破坏这段代码？

没有exports.handler的工作代码：

var ua = 'Mozilla/5.0 (iPad; CPU OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13B143 Safari/601.1'
var casper = require('casper').create({
    viewportSize: {width: 768, height: 1024},
    userAgent: ua
});
var login = {email: 'fakeemail@gmail.com', pw: 'fakepw'}
var usrObj = {
    succ: {},
    err: []
};

//exit function
function exit() {
    setTimeout(function() {
        casper.exit();
        casper.bypass(1);
    }, 10);
}
//success & error message function
function message(dat) {
    if (dat === 'credentials') {
        console.log('Error: Login credentials are missing');
        return exit();
    }
    else if (dat) {
        console.log(dat);
        return exit();
    }

    if (usrObj['err'].length > 0) {
        console.log('Error not empty...');
        console.log(usrObj.err);
        return exit();
    }
    else if (usrObj['succ']) {
        console.log('Success not empty...');
        console.log(JSON.stringify(usrObj.succ));
        return exit();
    }

}

//trim login credentials
login.email = login.email.trim();
login.pw = login.pw.trim();

if (login.email && login.pw) {

    casper.start('https://vimeo.com/log_in');
    casper.waitForSelector('form#login_form',
        function success() {
            this.echo(this.getCurrentUrl());
            this.sendKeys('form#login_form input[name="email"]', login.email);
            this.sendKeys('form#login_form input[name="password"]', login.pw);
            this.click('form#login_form input[type=submit][value="Log in with email"]');
        },
        function fail() {
            message('Error with Vimeo [page not loading]')
        }
    );
    casper.waitForSelector('#page_header>h1>a',
        function success() {
            this.echo(this.getCurrentUrl()); 
            usrObj['succ']['uname'] = this.getHTML('span.topnav_user_name');
            usrObj['succ']['profile'] = this.getElementAttribute('li.topnav_user_profile>a', 'href');
            var test = [];
            if (!usrObj.succ.uname) {test.push('Username not retrieved')}
            if (!usrObj.succ.profile) {test.push('Profile link not retrieved')}
            if (test.length > 0) {message(test.join('
'));}
            //else {message();}
        }, 
        function fail() {
            message('Login not successful');
        }
    ); 
    casper.thenOpen('https://vimeo.com/staceydavidgearz', 
        function success() {
            this.echo('Stacey David Profile: ' + this.getTitle());
            this.echo(this.getCurrentUrl()); 
            var finish = function() {
                usrObj['succ']['foll'] = true;
                message();
            }
            //var foll = this.getHTML('button[data-fatal-attraction="container:profile_page|component:follow"] > span');
            var foll = this.getElementAttribute('button[data-fatal-attraction="container:profile_page|component:follow"] > svg', 'viewBox');
            if (foll === '0 0 10 10') {
                this.click('button[data-fatal-attraction="container:profile_page|component:follow"]');
                setTimeout(function() {
                    foll = this.getElementAttribute('button[data-fatal-attraction="container:profile_page|component:follow"] > svg', 'viewBox');
                    if (foll === '0 0 10 10') {
                        message('Can\'t follow SD');

                    }
                    else {finish();}
                }, 250);
            }
            else {
                finish();
            }
        },
        function fail() {
            message('Not going to Stacey David profile page.');
        }
    );

    casper.run();
}
else {message('credentials');}

exports.handler中的代码失败：

var ua = 'Mozilla/5.0 (iPad; CPU OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13B143 Safari/601.1';

var casper = require('casper').create({
    viewportSize: {width: 768, height: 1024},
    userAgent: ua//,
    //verbose: true,
    //logLevel: 'debug'
});

exports.handler = function (event, context) {

    var login = {};
    var usrObj = {
        succ: {},
        err: []
    };
    //exit function
    var exit = function() {
        setTimeout(function() {
            casper.page.close();
            casper.exit();
            casper.bypass(1);
        }, 10);
    };
    //success & error message function
    var message = function(dat) {
        if (dat === 'credentials') {
            usrObj['err'].push('Error: Login credentials are missing');
        }
        else if (dat) {
            usrObj['err'].push(dat);
        }

        if (usrObj['err'].length > 0) {
            console.log('Error not empty...');
            console.log(JSON.stringify(usrObj.err));
            context.fail(JSON.stringify(usrObj.err));
            return exit();
        }
        else if (usrObj['succ']) {
            console.log('Success not empty...');
            console.log(JSON.stringify(usrObj.succ));
            context.succeed(JSON.stringify(usrObj.succ));
            return exit();
        }
    };

    //trim login credentials
    login.email = event.email;
    login.pw = event.pw;

    if (login.email && login.pw) {

        casper.start('https://vimeo.com/log_in');
        casper.waitForSelector('form#login_form',
            function success() {
                this.echo(this.getCurrentUrl());
                this.sendKeys('form#login_form input[name="email"]', login.email);
                this.sendKeys('form#login_form input[name="password"]', login.pw);
                this.click('form#login_form input[type=submit][value="Log in with email"]');
            },
            function fail() {
                message('Error with Vimeo [page not loading]')
            }
        );
        casper.waitForSelector('#page_header>h1>a',
            function success() {
                this.echo(this.getCurrentUrl()); 
                usrObj['succ']['uname'] = this.getHTML('span.topnav_user_name');
                usrObj['succ']['profile'] = this.getElementAttribute('li.topnav_user_profile>a', 'href');
                var test = [];
                if (!usrObj.succ.uname) {test.push('Username not retrieved')}
                if (!usrObj.succ.profile) {test.push('Profile link not retrieved')}
                if (test.length > 0) {message(test.join('
'));}
                //else {message();}
            }, 
            function fail() {
                message('Login not successful');
            }
        ); 
        casper.thenOpen('https://vimeo.com/staceydavidgearz', 
            function success() {
                this.echo('Stacey David Profile: ' + this.getTitle());
                this.echo(this.getCurrentUrl()); 
                var finish = function() {
                    usrObj['succ']['foll'] = true;
                    message();
                }
                var foll = this.getElementAttribute('button[data-fatal-attraction="container:profile_page|component:follow"] > svg', 'viewBox');
                if (foll === '0 0 10 10') {
                    this.click('button[data-fatal-attraction="container:profile_page|component:follow"]');
                    setTimeout(function() {
                        foll = this.getElementAttribute('button[data-fatal-attraction="container:profile_page|component:follow"] > svg', 'viewBox');
                        if (foll === '0 0 10 10') {
                            message('Can\'t follow SD');

                        }
                        else {finish();}
                    }, 250);
                }
                else {
                    finish();
                }
            },
            function fail() {
                message('Not going to Stacey David profile page.');
            }
        );

        casper.run();
    }
    else {message('credentials');}
};

Lambda回复：

身体

[]

日志：

Calling casperJS:  /var/task/node_modules/casperjs/bin/casperjs [ '/var/task/casperjs-script.js' ] { PHANTOMJS_EXECUTABLE: '/var/task/phantomjs' }
child process exited with code 1