testing question

[CSharper]

In my solution, I seperate the code into one project and test into
another project (NUnit). Now, in one of my test class, I need to
reference a file. This file can not be created on the fly and it has
to be added to the test project and during the testing, I need to load
them from project file and use it for testing. This makes the testing
easy since there will be no external dependency. My question is, how
could I achive this? or is there a better way to do this?
Thanks.

 

[Jon Skeet [C# MVP]]

In my solution, I seperate the code into one project and test into
another project (NUnit). Now, in one of my test class, I need to
reference a file. This file can not be created on the fly and it has
to be added to the test project and during the testing, I need to load
them from project file and use it for testing. This makes the testing
easy since there will be no external dependency. My question is, how
could I achive this? or is there a better way to do this?

Do you need it to reference an actual file, or just the data? I've
always found that adding files to the assembly and then calling
Assembly.GetResourceAsStream is a good way of working. You don't get
hundreds of files cluttering up the output directory, but you can still
work on them sensibly in Visual Studio.

 

[Peter Morris]

The constructor of your class could take an IServiceProvider instance. When
it needs the file contents you would ask it for a specific interface

public interface IFileContentProvider
{
byte[] GetFileContent(string fileName);
}

So you can do something like this

IFileContentProvider fcp =
(IFileContentProvider)seviceProvider.GetService(typeof(IFileContentProvider));
byte[] data = fcp.GetFileContent("c:\\temp\\data.txt");


In the test you can use a mocking framework (I use Rhino Mocks) to do this

MockRepository mocks = new MockRepository();
mocks.RecordAll();

IFileContentProvider mockfcp = mocks.StrictMock<IFileContentProvider>();

IServiceProvider mockServiceProvider = mock.StrictMock<IServiceProvider>();
Expect.Call(mockServiceProvider.GetService(typeof(IFileContentProvider)).Return(mockfcp);

byte[] result = ( some pre-defined test data here )
Expect.Call(mockfcp.GetFileContent("c:\\temp\\data.txt")).Return(result);

mocks.ReplayAll();

YourClass yc = new YourClass(mockServiceProvider);
yc.DoSomething();

mocks.VerifyAll();





Pete

 

[CSharper]

The constructor of your class could take an IServiceProvider instance.  When
it needs the file contents you would ask it for a specific interface

public interface IFileContentProvider
{
    byte[] GetFileContent(string fileName);

}

So you can do something like this

IFileContentProvider fcp =
(IFileContentProvider)seviceProvider.GetService(typeof(IFileContentProvider ));
byte[] data = fcp.GetFileContent("c:\\temp\\data.txt");

In the test you can use a mocking framework (I use Rhino Mocks) to do this

MockRepository mocks = new MockRepository();
mocks.RecordAll();

IFileContentProvider mockfcp = mocks.StrictMock<IFileContentProvider>();

IServiceProvider mockServiceProvider = mock.StrictMock<IServiceProvider>();
Expect.Call(mockServiceProvider.GetService(typeof(IFileContentProvider)).Re turn(mockfcp);

byte[] result = ( some pre-defined test data here )
Expect.Call(mockfcp.GetFileContent("c:\\temp\\data.txt")).Return(result);

mocks.ReplayAll();

YourClass yc = new YourClass(mockServiceProvider);
yc.DoSomething();

mocks.VerifyAll();

Pete

Thank you both for the great answer.