Implementing CollectionConstraints across NUnit versions

Question

We've implemented a CollectionConstraint for Nunit in version 2.4.3 in C#. Some of our developers have already upgraded to version 2.4.7 though, and they get project creation errors when compiling. The error is

doMatch: no suitable method found to override

Any advice on how to get this constraint so it compiles version-agnostically?

Answer 1

Unfortunately the constraint API changed in incompatible ways for custom constraints in 2.4.6. NUnit 2.4.5 and earlier used an IConstraint interface and in 2.4.6 it was changed to a Constraint abstract base class. There was an optional Constraint base class in 2.4.5 and earlier, but the class is not consistent between versions.

Therefore there is no way to make a compiled dll work with both versions of NUnit. Everyone should upgrade to the same version of NUnit.

Sorry I'm sure this is not the answer you're looking for.

Sam