public void it_can_open_any_file_for_read_and_write_and_seek()
{
var fileSystem = new DefaultFileSystem();
var anyFile = fileSystem.New(NewRandomTempFile());
using (var theStream = fileSystem.Open(anyFile)) {
Assert.IsTrue(theStream.CanRead , "Expected the resultant stream to be readable");
Assert.IsTrue(theStream.CanWrite, "Expected the resultant stream to be writable");
Assert.IsTrue(theStream.CanSeek , "Expected the resultant stream to be seekable");
}
}
public void it_fails_to_create_a_new_file_if_the_file_already_exists()
{
var theFilePath = NewRandomTempFile();
var fileSystem = new DefaultFileSystem();
fileSystem.New(theFilePath);
Assert.IsTrue(File.Exists(theFilePath),
"Invalid test data, The file <{0}> does not exist. " +
"The file must exist before a create attempt is tried.",
theFilePath
);
Assert.Throws<IOException>(() => fileSystem.New(theFilePath),
"Expected trying to create a file that already exists to fail with error"
);
}
private void AssertFlushesAutomatically(Byte[] bytes)
{
var fileSystem = new DefaultFileSystem();
var theFilePath = fileSystem.New(NewRandomTempFile());
Assert.That(theFilePath.Length, Is.EqualTo(0),
"Expected the file to be empty to start with"
);
using (var _out = fileSystem.Open(theFilePath)) {
_out.Write(bytes, 0, bytes.Length);
theFilePath.Refresh();
Assert.AreEqual(bytes.Length, theFilePath.Length,
"Expected the bytes to have been automatically flushed because the buffer was filled"
);
}
}
private void AssertDoesNotFlushAutomatically(Byte[] bytes)
{
var fileSystem = new DefaultFileSystem();
var theFilePath = fileSystem.New(NewRandomTempFile());
Assert.That(theFilePath.Length, Is.EqualTo(0),
"Expected the file to be empty to start with"
);
using (var _out = fileSystem.Open(theFilePath)) {
_out.Write(bytes, 0, bytes.Length);
theFilePath.Refresh();
Assert.AreEqual(0, theFilePath.Length,
"Expected that the bytes would not be flushed because the buffer is not yet full"
);
}
}
public void you_need_to_flush_a_file_stream_to_propagate_bytes_to_disk_unless_buffer_is_full()
{
var fileSystem = new DefaultFileSystem();
var theFilePath = fileSystem.New(NewRandomTempFile());
using (var _out = fileSystem.Open(theFilePath)) {
var bytes = Encoding.UTF8.GetBytes("An example string");
_out.Write(bytes, 0, bytes.Length);
Assert.That(theFilePath.Length, Is.EqualTo(0),
"Expected the bytes to have been buffered and not yet written to disk"
);
_out.Flush();
theFilePath.Refresh();
Assert.That(theFilePath.Length, Is.GreaterThan(0),
"Expected the bytes to have been written to disk now that the stream has been flushed"
);
}
}
public void it_opens_the_file_supplied()
{
var fileSystem = new DefaultFileSystem();
var anyFile = fileSystem.New(NewRandomTempFile());
var theExpectedText = "Let’s make toast the American way, you burn it and I’ll scrape it.";
using (var theStream = fileSystem.Open(anyFile)) {
using (var writer = new StreamWriter(theStream)) {
writer.Write(theExpectedText);
}
}
var theActualTextInTheFile = File.ReadAllText(anyFile.FullName);
Assert.AreEqual(theExpectedText, theActualTextInTheFile,
"Expected the text in the file <{0}> to match because we asked DefaultFileSystem to " +
"open it and then we wrote that text to it. " +
"This means the file we asked to be opened was not opened (because the write was successful).",
anyFile
);
}