Is this a good or bad way to use constructor chaining? (... to allow for testing).
- by panamack
My motivation for chaining my class constructors here is so that I have a default constructor for mainstream use by my application and a second that allows me to inject a mock and a stub.
It just seems a bit ugly 'new'-ing things in the ":this(...)" call and counter-intuitive calling a parametrized constructor from a default constructor , I wondered what other people would do here?
(FYI - SystemWrapper)
using SystemWrapper;
public class MyDirectoryWorker{
// SystemWrapper interface allows for stub of sealed .Net class.
private IDirectoryInfoWrap dirInf;
private FileSystemWatcher watcher;
public MyDirectoryWorker()
: this(
new DirectoryInfoWrap(new DirectoryInfo(MyDirPath)),
new FileSystemWatcher()) { }
public MyDirectoryWorker(IDirectoryInfoWrap dirInf, FileSystemWatcher watcher)
{
this.dirInf = dirInf;
if(!dirInf.Exists){
dirInf.Create();
}
this.watcher = watcher;
watcher.Path = dirInf.FullName;
watcher.NotifyFilter = NotifyFilters.FileName;
watcher.Created += new FileSystemEventHandler(watcher_Created);
watcher.Deleted += new FileSystemEventHandler(watcher_Deleted);
watcher.Renamed += new RenamedEventHandler(watcher_Renamed);
watcher.EnableRaisingEvents = true;
}
public static string MyDirPath{get{return Settings.Default.MyDefaultDirPath;}}
// etc...
}
