Fabian
I hadn't noticed the recursive clone issue since the default copy happens
to give the right result at present. But since the point is to take
control of object copying I will have to avoid serialization.
I will use your idea of a maintenance free check that no fields I care
about have default values in the test.
Thanks
David.
On Wed, 31 Oct 2007 13:54:09 +0100, Fabian Schmied <[EMAIL PROTECTED]>
wrote:
>
>There are two important drawbacks about cloning by serialization that
>one should be aware of:
>
>1- Performance: Using BinaryFormatter is much slower than a manual
>implementation of Clone, and it's probably also much slower than a
>reflection-based implementation. Of course, as "slow" is relative,
>that's only an issue if you need to do a lot of cloning within tight
>time constraints.
>
>2- Semantics: A well-behaved implementation of Clone would be expected
>to recursively call Clone on any ICloneable objects it contains. This
>does not happen when you do binary serialization, which can be an
>issue.
>
>Regarding the original question (in case you don't want to use
>serialization): You can use Reflection to check whether an object has
>been cloned correctly, as others have suggested, but as you've
>noticed, this only moves the problem to the issue of setting all
>fields of an object prior to testing.
>
>However, this is something you can ensure in your test: if you have a
>reflection-based comparer, you can not only test whether the object
>has been cloned correctly, but also that the source object is not
>equal to a "default" one.
>
>Illustrative code:
>
>[Test]
>public void Clone()
>{
> MyClass source = GetCloneTestSource();
> MyClass defaultObject = new MyClass();
> Assert.IsFalse (ReflectionBasedComparer.AreEqual (source,
> defaultObject), "Forgot to initialize field for cloning.");
> MyClass clone = source.Clone();
> Assert.IsTrue (ReflectionBasedComparer.AreEqual (source, clone),
> "Clone failed");
>}
>
>Fabian
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