docs/articles/nunit/writing-tests/constraints/DictionaryContainsKeyConstraint.md
DictionaryContainsKeyConstraint is used to test whether a dictionary
contains an expected object as a key.
DictionaryContainsKeyConstraint(object)
Contains.Key(object)
Does.ContainKey(object)
Does.Not.ContainKey(object)
...WithValue(object expectedValue)
As of version 4.4.0 of NUnit the other modifiers were removed as they were non-functional.
NUnit's ContainKey works the same as the ContainsKey method on Dictionary
It uses the comparer specified when the dictionary was created.
var caseSensitiveDictionary = new Dictionary<string, string>(StringComparer.Ordinal)
{
["Hello"] = "World",
};
Assert.That(caseSensitiveDictionary, Does.ContainKey("Hello"));
Assert.That(caseSensitiveDictionary, Does.Not.ContainKey("hello"));
var caseInsensitiveDictionary = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
{
["Hello"] = "World",
};
Assert.That(caseInsensitiveDictionary, Does.ContainKey("Hello"));
Assert.That(caseInsensitiveDictionary, Does.ContainKey("hello"));
Assert.That(caseInsensitiveDictionary, Does.Not.ContainKey("hallo"));
// Note that the 'IgnoreCase' here is on the Value part, not the Key.
Assert.That(caseInsensitiveDictionary, Does.ContainKey("hello").WithValue("world").IgnoreCase);