Asp.net Core 中 IFormFile 字段的 xunit 测试

Question

我有一个 Asp.net 核心方法，其定义如下。

[HttpPost]
public IActionResult Upload(IFormFile file)
{
    if (file == null || file.Length == 0)
        throw new Exception("file should not be null");

    var originalFileName = ContentDispositionHeaderValue
        .Parse(file.ContentDisposition)
        .FileName
        .Trim('"');

    file.SaveAs("your_file_full_address");
}

我想为此函数创建 XUnit 测试，如何模拟 IFormFile？

更新：

控制器：

[HttpPost]
public async Task<ActionResult> Post(IFormFile file)
{

    var path = Path.Combine(@"E:\path", file.FileName);

    using (var stream = new FileStream(path, FileMode.Create))
    {
        await file.CopyToAsync(stream);
    }
    return Ok();
}

Xunit 测试

[Fact]
public async void Test1()
{
    var file = new Mock<IFormFile>();
    var sourceImg = File.OpenRead(@"source image path");
    var stream = new MemoryStream();
    var writer = new StreamWriter(stream);
    writer.Write(sourceImg);
    writer.Flush();
    stream.Position = 0;
    var fileName = "QQ.png";
    file.Setup(f => f.OpenReadStream()).Returns(stream);
    file.Setup(f => f.FileName).Returns(fileName);
    file.Setup(f => f.Length).Returns(stream.Length);

    var controller = new ValuesController();
    var inputFile = file.Object;

    var result = await controller.Post(inputFile);

    //Assert.IsAssignableFrom(result, typeof(IActionResult));
}

但是，我在目标路径中得到了空图像。

Answer 1

在使用 IFormFile 依赖项进行测试时，模拟最少的必需成员来执行测试。在上面的 Controller 中使用了 FileName 属性和 CopyToAsync 方法。这些应该为测试设置。

public async Task Test1() {
    // Arrange.
    var file = new Mock<IFormFile>();
    var sourceImg = File.OpenRead(@"source image path");
    var ms = new MemoryStream();
    var writer = new StreamWriter(ms);
    writer.Write(sourceImg);
    writer.Flush();
    ms.Position = 0;
    var fileName = "QQ.png";
    file.Setup(f => f.FileName).Returns(fileName).Verifiable();
    file.Setup(_ => _.CopyToAsync(It.IsAny<Stream>(), It.IsAny<CancellationToken>()))
        .Returns((Stream stream, CancellationToken token) => ms.CopyToAsync(stream))
        .Verifiable();

    var controller = new ValuesController();
    var inputFile = file.Object;

    // Act.
    var result = await controller.Post(inputFile);

    //Assert.
    file.Verify();
    //...
}

虽然在评论中提到问题只是一个演示，但应该抽象出与文件系统的紧密耦合以提供更好的灵活性

Answer 2

您可以像这样创建一个实际实例...

bytes[] filebytes = Encoding.UTF8.GetBytes("dummy image");
IFormFile file = new FormFile(new MemoryStream(filebytes), 0, filebytes.Length, "Data", "image.png");

Answer 3

我必须使用正确的用户对正确的 jpeg 文件上传进行单元测试，所以：

private ControllerContext RequestWithFile()
{
var httpContext = new DefaultHttpContext();
httpContext.Request.Headers.Add("Content-Type", "multipart/form-data");

var sampleImagePath = host.WebRootPath + SampleImagePath; //path to correct image    
var b1 = new Bitmap(sampleImagePath).ToByteArray(ImageFormat.Jpeg);

MemoryStream ms = new MemoryStream(b1);    
var fileMock = new Mock<IFormFile>();

fileMock.Setup(f => f.Name).Returns("files");
fileMock.Setup(f => f.FileName).Returns("sampleImage.jpg");
fileMock.Setup(f => f.Length).Returns(b1.Length);
fileMock.Setup(_ => _.CopyToAsync(It.IsAny<Stream>(), It.IsAny<CancellationToken>()))
.Returns((Stream stream, CancellationToken token) => ms.CopyToAsync(stream))
.Verifiable();              

string val = "form-data; name=";      

val += "\";
val += "\"";
val += "files";
val += "\";
val += "\"";
val += "; filename=";
val += "\";
val += "\"";
val += "sampleImage.jpg";
val += "\";
val += "\"";


fileMock.Setup(f => f.ContentType).Returns(val);
fileMock.Setup(f => f.ContentDisposition).Returns("image/jpeg");      


httpContext.User = ClaimsPrincipal; //user part, you might not need it
httpContext.Request.Form = 
new FormCollection(new Dictionary<string, StringValues>(), new FormFileCollection { fileMock.Object });
var actx = new ActionContext(httpContext, new RouteData(), new ControllerActionDescriptor());

return new ControllerContext(actx);
}

然后在测试中：

[Fact]
public async void TestUploadFile_byFile()
{
var amountOfPosts = _dbContext.Posts.Count();
var amountOfPics = _dbContext.SmallImages.Count();

sut.ControllerContext = RequestWithFile();
var ret = await sut.UploadNewDogePOST(new Doge.Areas.User.Models.UploadDoge());

var amountOfPosts2 = _dbContext.Posts.Count();
var amountOfPics2 = _dbContext.SmallImages.Count();

Assert.True(amountOfPosts < amountOfPosts2);
Assert.True(amountOfPics < amountOfPics2);

var lastImage = _dbContext.SmallImages.Include(im => im.DogeBigImage).Last();
var sampleImagePath = host.WebRootPath + SampleImagePath;
var b1 = new Bitmap(sampleImagePath).ToByteArray(ImageFormat.Jpeg);

Assert.True(b1.Length == lastImage.DogeBigImage.Image.Length);

Assert.IsType<RedirectToActionResult>(ret);
Assert.Equal("Index", ((RedirectToActionResult)ret).ActionName);

}

Asp.net Core 中 IFormFile 字段的 xunit 测试

xunit test for IFormFile field in Asp.net Core

c#

unit-testing

moq

xunit

asp.net-core