public void ExampleOfATestSimulatingFileContainingMultipleLines()
{
string[] lines = ArraryContaining("Hello World", "Are you ok?");
using (ClassUsingFile obj = new ClassUsingFile(StreamContaining(StringListBuiltFrom(lines))))
{
string[] actual = ArraryContaining(obj.GetStreamContentsAsLines());
Assert.That(actual, Is.EqualTo(lines));
}
}
public void PreferPassingInMemoryStreamsRatherThanFilePath()
{
string s = "Hello World";
using (ClassUsingFile unit = new ClassUsingFile(StreamContaining(s)))
{
Assert.That(unit.GetStreamContents(), Is.EqualTo(s));
}
}
public void ExampleOfHowToWriteTestThatUsesPhysicalFiles()
{
//strictly if a test touches the file system its not a unit test
//(ie a unit test must be fast)!
FileInfo file = TempFile.CreateWithContents("Hello");
using (ClassUsingFile unit = new ClassUsingFile(file.FullName))
{
Assert.That(unit.GetStreamContents(), Is.EqualTo("Hello"));
}
}
public void PreferPassingInTextReaderRatherThanFilePath()
{
//if the Class Under Test (CUT) is expected to work against a file,
//prefer passing in a TextReader/Writer. This allows our unit test to
//simulate a file with just an in-memory string.
//This assumes that the file being worked against is a text file.
//If this is not true then prefer simulating a file using
//MemoryStream and passing this to the CUT (see previous examples)
string[] lines = ArraryContaining("Hello World", "Are you ok?");
using (ClassUsingFile obj = new ClassUsingFile(ReaderContaining(StringListBuiltFrom(lines))))
{
string[] actual = ArraryContaining(obj.GetStreamContentsAsLines());
Assert.That(actual, Is.EqualTo(lines));
}
}
