public void Should_use_member_hashing_function()
{
var foo = new Foo();
var configuration = new GetHashCodeConfiguration <Foo>().For(f => f.Number, (h, i) => 777);
Func <Foo, int> customFn = new GetHashCodeExpressionBuilder <Foo>(configuration)
.Build()
.Compile();
int customNumberHash = customFn(foo);
customNumberHash.Should().BeNotEqualToDefaultHashCodeOf(foo);
}
public void Should_use_provided_primes()
{
var foo = new Foo();
var configuration = new GetHashCodeConfiguration <Foo>().WithPrimes(31, 41);
Func <Foo, int> primesFn = new GetHashCodeExpressionBuilder <Foo>(configuration)
.Build()
.Compile();
int customPrimeHash = primesFn(foo);
customPrimeHash.Should().BeNotEqualToDefaultHashCodeOf(foo);
}
public void Should_not_take_member_into_account_if_it_is_registered_as_skipped()
{
var foo = new Foo();
var configuration = new GetHashCodeConfiguration <Foo>().Skip(f => f.Number);
Func <Foo, int> skippedFn = new GetHashCodeExpressionBuilder <Foo>(configuration)
.Build()
.Compile();
int skippedNumberHash = skippedFn(foo);
skippedNumberHash.Should().BeNotEqualToDefaultHashCodeOf(foo);
}
public void Should_hash_collection_items()
{
var item = new Mock <Foo>();
var foo = new Foo()
{
Foos = new [] { item.Object, item.Object }
};
Func <Foo, int> hashFn = new GetHashCodeExpressionBuilder <Foo>().Build().Compile();
hashFn(foo);
item.Verify(i => i.GetHashCode(), Times.Exactly(foo.Foos.Length));
}
public void Should_not_hash_collection_items_if_registered()
{
var item = new Mock <Foo>();
var foo = new Foo()
{
Foos = new[] { item.Object, item.Object }
};
var configuration = new GetHashCodeConfiguration <Foo>().ExcludeCollectionItems();
Func <Foo, int> hashFn = new GetHashCodeExpressionBuilder <Foo>(configuration)
.Build()
.Compile();
hashFn(foo);
item.Verify(i => i.GetHashCode(), Times.Exactly(0));
}
public void Should_succeed_with_overflow()
{
checked
{
var foo = new Foo()
{
Number = int.MaxValue, Text = "some text"
};
var configuration = new GetHashCodeConfiguration <Foo>().WithPrimes(int.MaxValue, int.MaxValue);
Func <Foo, int> hashFn = new GetHashCodeExpressionBuilder <Foo>(configuration)
.Build()
.Compile();
Action action = () => hashFn(foo);
action.ShouldNotThrow();
}
}
public void Should_take_into_account_order_of_items_in_collection_property()
{
var fooOrdered = new Foo()
{
Words = new[] { "a", "b" }
};
var fooReversed = new Foo()
{
Words = new[] { "b", "a" }
};
Func <Foo, int> hashFn = new GetHashCodeExpressionBuilder <Foo>().Build().Compile();
int orderedColHash = hashFn(fooOrdered);
int reversedColHash = hashFn(fooReversed);
orderedColHash.Should().NotBe(reversedColHash);
}
public static void Register([NotNull] Action <GetHashCodeConfiguration <T> > configure)
{
try
{
var configuration = new GetHashCodeConfiguration <T>();
configure(configuration);
Func <T, int> hashFn = new GetHashCodeExpressionBuilder <T>(configuration).Build().Compile();
if (Interlocked.CompareExchange(ref hasher, hashFn, defaultHasher) != defaultHasher)
{
throw new InvalidOperationException($"Type '{typeof(T)}' was already registered with FastEasyHash");
}
}
catch (Exception ex)
{
initializationException = ex;
}
}
public static void BeNotEqualToDefaultHashCodeOf <T>(this NumericAssertions <int> assertions, T value)
{
Func <T, int> defaultHashFn = new GetHashCodeExpressionBuilder <T>().Build().Compile();
assertions.Should().NotBe(defaultHashFn(value));
}
