将Moq与SystemWrapper结合使用以对Action c＃MVC进行单元测试

Question

I'm trying to test an action where I have an InputStream, and I don't really know how to procede.

I'm trying with mocking the class and I get notice that we cannot Mock the System.IO because we don't have an abstraction layer.

So, after some searchs, I'm oriented to use a package that add a abstraction layer of the IO system and wrap it. is "SystemWrapper", but I didn't successed to use it.

My goal: Is to check Excel file headers if it's the same as the canva format if the format excpected it will be true else false.

There is my code :

Function that I want to test:

public bool checkFileHeaders(UploadedFile file)
{
    ExcelPackage package = new ExcelPackage(file.filePath.InputStream);
    ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
    List<string> expectedArray = new List<string>();
    List<string> array = new List<string>();
    bool checkExprectedArrayWithReelArray = true;
    switch (file.typeFile)
    {
        case "headcount":
        expectedArray.AddRange(new string[] { "MLE", "NOM", "PRENOM", "type"      });
    try
    {
        array.AddRange(new string[] { (string)worksheet.Cells["A1"].Value,   (string)worksheet.Cells["B1"].Value, (string)worksheet.Cells["C1"].Value,   (string)worksheet.Cells["D1"].Value});
    }
    catch
    {
        checkExprectedArrayWithReelArray = false;
    }
    case "File2":
    expectedArray.AddRange(new string[] { "Field1", "Field2", "Field3" });
    try
    {
        array.AddRange(new string[] { (string)worksheet.Cells["A1"].Value, (string)worksheet.Cells["B1"].Value, (string)worksheet.Cells["C1"].Value});
    }
    catch
    {
        checkExprectedArrayWithReelArray = false;
    }
}

checkExprectedArrayWithReelArray = Enumerable.SequenceEqual(expectedArray.OrderBy(t => t), array.OrderBy(t => t));
package.Dispose();
return checkExprectedArrayWithReelArray;

}

Test Function :

    [TestMethod]
    public void CheckFileHeaders_STCWithExpectedFormat_ShouldReturnTrue()
    {
        var mockFileStream = new Mock<FileStreamWrap>();

        var _mockHttpStream = new Mock<HttpPostedFileBase>();
        _mockHttpStream.Setup(f => f.InputStream)
        .Returns( ??????);


        OpsReview.Core.Parsers.UploadedFile file = new OpsReview.Core.Parsers.UploadedFile
        {
            typeFile = "stc",
            filePath = _mockHttpStream.Object
        };
        var result = _controller.checkFileHeaders(file);
        result.Should().Be(true);
    }

Type of my Input stream Or, if you can give me another approach to follow it's will be great from you.

Thanks

Answer 1

You can mock it by setting up the InputStream to return the BaseStream of a StreamReader to a test file, eg:

var mockPostedFileBase = new Mock<HttpPostedFileBase>();
mockPostedFileBase.SetupGet(s => s.InputStream).Returns(new StreamReader(/* path to test file */).BaseStream);