const awsSdk = require('aws-sdk');
module.exports = {
downloadFile(bucketName, fileName, callback) {
var s3 = new awsSdk.S3();
var params = { Bucket: bucketName, Key: fileName };
var file = require('fs').createWriteStream('abcd.jpg');
var stream = s3.getObject(params).on('error', function (err) {
console.log(' download.on');
callback('error', null);
})
.createReadStream()
stream.pipe(file);
}
}
以上,是我需要在我的测试类中使用 proxyquire 模拟的代码。问题是,我无法模拟 getObject、on、createReadStream 等方法。同样在模拟之后,我需要从测试类发出错误事件,该事件将触发上述 on 方法,该方法将在测试异常的测试类中调用回调。
下面是我的测试类代码。
const proxyquire = require('proxyquire').noCallThru().noPreserveCache();
const sinon = require('sinon');
const emitter = require('events').EventEmitter;
function Download() {
emitter.call(this);
this.error = function () {
this.emit('error');
}
}
describe('S3 download test', () => {
awsSdkMock = {}
awsSdkMock.config = {};
awsSdkMock.config.region = { };
var s3Instance = {};
awsSdkMock.S3 = function (){
return s3Instance;
};
var object = {};
s3Instance.getObject = function (params){
return object;
};
var request = {};
const errorCallBack = sinon.spy();
var err = 'error';
object.on = function (err, errorCallBack) {
console.log('object.on');
errorCallBack();
return request;
};
var stream = {};
request.createReadStream = function(){
console.log('createReadStream');
return stream
};
stream.pipe = function(file){
console.log('download.error');
// download.error();
};
Download.prototype.__proto__ = emitter.prototype;
var download = new Download();
const s3 = proxyquire('./../../../modules/s3', {
'aws-sdk': awsSdkMock
})
it('Error in download test', (done) => {
const errorCallBack = sinon.spy();
s3.downloadFile('123', 'abcd', errorCallBack);
sinon.assert.calledWith(errorCallBack, 'error', null);
done();
});
})
任何帮助表示赞赏。