我正在努力使这个测试工作，但我无法理解如何使用FileReader编写测试。这是我的代码
function Uploader(file) {
this.file = file;
}
Uploader.prototype = (function() {
function upload_file(file, file_contents) {
var file_data = new FormData()
file_data.append('filename', file.name)
file_data.append('mimetype', file.type)
file_data.append('data', file_contents)
file_data.append('size', file.size)
$.ajax({
url: "/upload/file",
type: "POST",
data: file_contents,
contentType: file.type,
success: function(){
// $("#thumbnail").attr("src", "/upload/thumbnail");
},
error: function(){
alert("Failed");
},
xhr: function() {
myXhr = $.ajaxSettings.xhr();
if(myXhr.upload){
myXhr.upload.addEventListener('progress',showProgress, false);
} else {
console.log("Upload progress is not supported.");
}
return myXhr;
}
});
}
return {
upload : function() {
var self = this,
reader = new FileReader(),
file_content = {};
reader.onload = function(e) {
file_content = e.target.result.split(',')[1];
upload_file(self.file, file_content);
}
}
};
})();
这是我的考验
describe("Uploader", function() {
it("should upload a file successfully", function() {
spyOn($, "ajax");
var fakeFile = {};
var uploader = new Uploader(fakeFile);
uploader.upload();
expect($.ajax.mostRecentCall.args[0]["url"]).toEqual("/upload/file");
})
});
但它永远不会到达reader.onload。
这里的问题是使用reader.onload很难测试。您可以使用reader.addEventListener，这样您就可以监视全局FileReader对象并返回一个模拟：
eventListener = jasmine.createSpy();
spyOn(window, "FileReader").andReturn({
addEventListener: eventListener
})
那么你可以自己激活onload回调：
expect(eventListener.mostRecentCall.args[0]).toEqual('load');
eventListener.mostRecentCall.args[1]({
target:{
result:'the result you wanna test'
}
})
此语法在2.0中已更改。下面的代码给出了一个基于AndreasKöberle答案但使用新语法的示例
// create a mock object, its a function with some inspection methods attached
var eventListener = jasmine.createSpy();
// this is going to be returned when FileReader is instantiated
var dummyFileReader = { addEventListener: eventListener };
// pipe the dummy FileReader to the application when FileReader is called on window
// this works because window.FileReader() is equivalent to new FileReader()
spyOn(window, "FileReader").and.returnValue(dummyFileReader)
// your application will do something like this ..
var reader = new FileReader();
// .. and attach the onload event handler
reader.addEventListener('load', function(e) {
// obviously this wouldnt be in your app - but it demonstrates that this is the
// function called by the last line - onloadHandler(event);
expect(e.target.result).toEqual('url');
// jasmine async callback
done();
});
// if addEventListener was called on the spy then mostRecent() will be an object.
// if not it will be null so careful with that. the args array contains the
// arguments that addEventListener was called with. in our case arg[0] is the event name ..
expect(eventListener.calls.mostRecent().args[0]).toEqual('load');
// .. and arg[1] is the event handler function
var onloadHandler = eventListener.calls.mostRecent().args[1];
// which means we can make a dummy event object ..
var event = { target : { result : 'url' } };
// .. and call the applications event handler with our test data as if the user had
// chosen a file via the picker
onloadHandler(event);
我觉得自己下次做的最容易。
结果 - 我不嘲笑Filereader
// CONTROLLER
$scope.handleFile = function (e) {
var f = e[0];
$scope.myFile = {
name: "",
size: "",
base64: ""
};
var reader = new FileReader();
reader.onload = function (e) {
try {
var buffer = e.target.result;
$scope.myFile = {
name: f.name,
size: f.size,
base64: XLSX.arrayBufferToBase64(buffer)
};
$scope.$apply();
} catch (error) {
$scope.error = "ERROR!";
$scope.$apply();
}
};
reader.readAsArrayBuffer(f);
//run in test env
if ( typeof jasmine == 'object') {reader.onload(e)}
}
//JASMINE TEST
it('handleFile 0', function () {
var fileContentsEncodedInHex = ["\x45\x6e\x63\x6f\x64\x65\x49\x6e\x48\x65\x78\x42\x65\x63\x61\x75\x73\x65\x42\x69\x6e\x61\x72\x79\x46\x69\x6c\x65\x73\x43\x6f\x6e\x74\x61\x69\x6e\x55\x6e\x70\x72\x69\x6e\x74\x61\x62\x6c\x65\x43\x68\x61\x72\x61\x63\x74\x65\x72\x73"];
var blob = new Blob(fileContentsEncodedInHex);
blob.type = 'application/zip';
blob.name = 'name';
blob.size = 11111;
var e = {0: blob, target: {result: {}}};
$scope.handleFile(e);
expect($scope.error ).toEqual("");
});我也面临类似的问题，并且能够在不使用addeventlistener的情况下实现它。我曾经使用过onloadend，所以下面是我做的。我的ts文件有以下代码： -
let reader = new FileReader();
reader.onloadend = function() {
let dataUrl = reader.result;
// Some working here
};
reader.readAsDataURL(blob);
我的spec文件（测试）案例代码： -
let mockFileReader = {
result:'',
readAsDataURL:(blobInput)=> {
console.log('readAsDataURL');
},
onloadend:()=> {
console.log('onloadend');
}
};
spyOn<any>(window, 'FileReader').and.returnValue(mockFileReader);
spyOn<any>(mockFileReader, 'readAsDataURL').and.callFake((blobInput)=> {
// debug your running application and assign to "encodedString" whatever
//value comes actually after using readAsDataURL for e.g.
//"data:*/*;base64,XoteIKsldk......"
mockFileReader.result = encodedString;
mockFileReader.onloadend();
});
这样你就模拟了FileReader对象，并向你自己的“readAsDataURL”返回了一个假调用。因此，现在当您的实际代码调用“reasAsDataURL”时，您调用伪函数，其中您在“结果”中分配编码字符串并调用“onloadend”函数，您已在代码（.ts）文件中分配了一个功能。因此它会被预期结果调用。希望能帮助到你。
当onloadend调用时，我努力想弄清楚如何测试readAsDataURL。这是我最终的结果。
生产代码：
loadFileDataIntoChargeback(tempFileList) {
var fileNamesAndData = [];
for (var i = 0, f; f = tempFileList[i]; i++) {
let theFile = tempFileList[i];
var reader = new FileReader();
reader.onloadend = ((theFile) => {
return (fileData) => {
var insertionIndex = this.chargeback.fileList.length;
this.chargeback.fileList.push({ FileName: theFile.name, Data: fileData.target.result, FileType: theFile.type });
this.loadFilePreviews(theFile, insertionIndex);
}
})(f);
reader.readAsDataURL(f);
}
this.fileInputPath = "";
}
测试代码：
describe('when the files are loaded into the chargeback', () => {
it('loads file previews', () => {
let mockFileReader = {
target: { result: '' },
readAsDataURL: (blobInput) => {},
onloadend: () => {}
};
spyOn(chargeback, "loadFilePreviews");
spyOn(window, 'FileReader').and.returnValue(mockFileReader);
spyOn(mockFileReader, 'readAsDataURL').and.callFake((blobInput) => {
mockFileReader.onloadend({ target: { result: "data:image/jpeg;base64,/9j/4QAYRXh" } });
});
var readFileList = chargeback.getArrayFromFileInput([getImageFile1()]);
chargeback.loadFileDataIntoChargeback(readFileList);
expect(chargeback.loadFilePreviews).toHaveBeenCalled();
});
});