ListMapper

Important

ListMapper has been deprecated as of NUnit Framework 3.13.2. The functionality was removed in NUnit Framework 4.0.

Unlike Constraint classes, ListMapper is used to modify the actual value argument to Assert.That(). It transforms the actual value, which must be a collection, creating a new collection to be tested against the supplied constraint. Currently, ListMapper supports one transformation: creating a collection of property values.

Normally, ListMapper will be used through the List.Map() syntax helper. The following example shows two forms of the same assert.

string[] strings = new string[] { "a", "ab", "abc" };
int[] lengths = new int[] { 1, 2, 3 };

Assert.That(List.Map(strings).Property("Length"),
       Is.EqualTo(lengths));

Assert.That(new ListMapper(strings).Property("Length"),
       Is.EqualTo(lengths));