code-contracts

Consider this immutable type: public class Settings { public string Path { get; private set; } [ContractInvariantMethod] private void ObjectInvariants() { Contract.Invariant(Path != null); } public Settings(string path) { Contract.Requires(path != null); Path = path; } } Two things to notice here: There is a contract invariant which ensures the Path property can never be null The constructor checks the path argument value to respect the previous contract invariant At this point, a Setting instance can never have a null Path property. Now, look at this type: public class Program { private

I am looking to validate method parameters in my code, in the most elegant fashion possible. Code Contracts don't seem to work in 2015. Does anyone use any alternatives? They're working on it: https://github.com/Microsoft/CodeContracts/pull/36 If you cannot wait, there are a few things that you can do to fix this: https://github.com/Microsoft/CodeContracts/issues/18 "The contract editor extensions now have a single VSIX package for all of the Visual Studio versions includign VS2015!" https://visualstudiogallery.msdn.microsoft.com/1ec7db13-3363-46c9-851f-1ce455f66970 I have installed

What is the recommended way for adding postconditions to async methods which return Task<T> ? I have read the following suggestion: http://social.msdn.microsoft.com/Forums/hu-HU/async/thread/52fc521c-473e-4bb2-a666-6c97a4dd3a39 The post suggests implementing each method as synchronous, contracting it, and then implementing an async counterpart as a simple wrapper. Unfortunately I don't see this as a workable solution (perhaps through my own misunderstanding): The async method, although assumed to be a wrapper for the sync method, is left without any real code contract and can therefore do as

See below for an explanation of what is going on I have a really weird issue where the exception caught is null. The code uses MEF and tries hard to report composition errors. Using the debugger I can see the exception being thrown (an InvalidOperationException ) but when it is caught by the last catch block in the code below the ex variable is null. This is true both in the debugger and when executing the code normally. static T ResolveWithErrorHandling<T>() where T : class { try { IocContainer.Compose(Settings.Default.IocConfiguration); return IocContainer.Resolve<T>(); } catch

Before I started using Code Contracts I sometimes ran into fiddlyness relating to parameter validation when using constructor chaining. This is easiest to explain with a (contrived) example: class Test { public Test(int i) { if (i == 0) throw new ArgumentOutOfRangeException("i", i, "i can't be 0"); } public Test(string s): this(int.Parse(s)) { if (s == null) throw new ArgumentNullException("s"); } } I want the Test(string) constructor to chain the Test(int) constructor, and to do so I use int.Parse() . Of course, int.Parse() doesn't like having a null argument, so if s is null it will throw