public void GetHashCode_TwoDictionariesHaveDifferentValue_ReturnDifferentHashCodes()
{
var reference = new Dictionary <string, string> {
{ "key1", "value1" }, { "key2", "value2" }
};
var other = new Dictionary <string, string> {
{ "key1", "value1" }, { "key2", "value3" }
};
var comparer = new DictionaryEqualityComparer <string, string>();
Assert.AreNotEqual(comparer.GetHashCode(reference), comparer.GetHashCode(other));
}
public void GetHashCode_Null_Throws()
{
var comparer = new DictionaryEqualityComparer <string, string>();
Assert.Throws <ArgumentNullException>(
() => comparer.GetHashCode(null));
}
public void Null()
{
Assert.True(_testComparer.Equals(null, null));
Assert.False(_testComparer.Equals(null, new Dictionary <string, string>()));
Assert.False(_testComparer.Equals(new Dictionary <string, string>(), null));
Assert.AreEqual(0, _testComparer.GetHashCode(null));
}
public void DictionaryEqualityComparerGetHashCodeReturnsDefaultHashCodeIfDictionaryIsEmpty()
{
const int expectedHashCode = 23;
var comparer = new DictionaryEqualityComparer <string, int>();
Dictionary <string, int> dictionary = new Dictionary <string, int>();
int result = comparer.GetHashCode(dictionary);
Assert.AreEqual(expectedHashCode, result);
}
public void DictionaryEqualityComparerGetHashCodeReturnsZeroIfDictionaryIsNull()
{
const int expectedHashCode = 0;
var comparer = new DictionaryEqualityComparer <string, int>();
Dictionary <string, int> dictionary = null;
int result = comparer.GetHashCode(dictionary);
Assert.AreEqual(expectedHashCode, result);
}
public void DictionaryEqualityComparerGetHashCodeReturnsSameHashCodeIfDictionaryContainsNullValues()
{
var comparer = new DictionaryEqualityComparer <string, int?>();
Dictionary <string, int?> dictionary = new Dictionary <string, int?>
{
{ "A", 1 },
{ "B", 2 },
{ "C", 3 },
{ "D", null },
};
//get the HashCode 2000 times to confirm it is consistent for lifetime of dictionary
HashSet <int> hashes = new HashSet <int>();
for (int i = 0; i < 2000; i++)
{
hashes.Add(comparer.GetHashCode(dictionary));
}
Assert.AreEqual(1, hashes.Count);
}
public int GetHashCode(IEqualityComparer comparer)
{
return(DictionaryEqualityComparer <TKey, TValue> .GetHashCode(this, comparer));
}
public void GetHashCode_Null_Throws()
{
var comparer = new DictionaryEqualityComparer<string, string>();
Assert.Throws<ArgumentNullException>(
() => comparer.GetHashCode(null));
}
public void GetHashCode_TwoDictionariesHaveDifferentValue_ReturnDifferentHashCodes()
{
var reference = new Dictionary<string, string> {{"key1", "value1"}, {"key2", "value2"}};
var other = new Dictionary<string, string> {{"key1", "value1"}, {"key2", "value3"}};
var comparer = new DictionaryEqualityComparer<string, string>();
Assert.AreNotEqual(comparer.GetHashCode(reference), comparer.GetHashCode(other));
}
public void GetHashCode_Null_Throws()
{
DictionaryEqualityComparer<string, string> comparer = new DictionaryEqualityComparer<string, string>();
comparer.GetHashCode(null);
}
public void GetHashCode_TwoDictionariesHaveDifferentValue_ReturnDifferentHashCodes()
{
Dictionary<string, string> reference = new Dictionary<string, string>();
reference.Add("key1", "value1");
reference.Add("key2", "value2");
Dictionary<string, string> other = new Dictionary<string, string>();
other.Add("key1", "value1");
other.Add("key2", "value3");
DictionaryEqualityComparer<string, string> comparer = new DictionaryEqualityComparer<string, string>();
Assert.AreNotEqual(comparer.GetHashCode(reference), comparer.GetHashCode(other));
}