HttpPostedFileBase 如何做单元测试

Question

ASP.NET MVC3 中一个Controller的Action需要HttpPostedFileBase，在做单元测试时，怎么为这个参数实例化一个文件呀？

Answer 1

建议使用Moq，参考代码（代码来源）：

[TestMethod]
public void TestUpload() {
    HomeController c = new HomeController();
    Mock<ControllerContext> cc = new Mock<ControllerContext>();
    UTF8Encoding enc = new UTF8Encoding();

    Mock<HttpPostedFileBase> file1 = new Mock<HttpPostedFileBase>();
    file1.Expect(d => d.FileName).Returns("test1.txt");
    file1.Expect(d => d.InputStream).Returns(new MemoryStream(enc.GetBytes(Resources.UploadTestFiles.test1)));

    Mock<HttpPostedFileBase> file2 = new Mock<HttpPostedFileBase>();
    file2.Expect(d => d.FileName).Returns("test2.txt");
    file2.Expect(d => d.InputStream).Returns(new MemoryStream(enc.GetBytes(Resources.UploadTestFiles.test2)));
                
    cc.Expect(d => d.HttpContext.Request.Files.Count).Returns(2);
    cc.Expect(d => d.HttpContext.Request.Files[0]).Returns(file1.Object);
    cc.Expect(d => d.HttpContext.Request.Files[1]).Returns(file2.Object);
    c.ControllerContext = cc.Object;

    ActionResult r = c.Upload();
    Assert.IsInstanceOfType(r, typeof(ContentResult));
    Assert.AreNotEqual("Uploaded 2 files.<br/>\nFile test1.txt: Contents of test file 1<br/>\nFile test2.txt: Contents of test file 2<br/>", ((ContentResult)r).Content);