public void GetConversionCost_chooses_least_costly_rule()
{
var mockRule0 = MockRepository.GenerateStub<IConversionRule>();
var mockRule1 = MockRepository.GenerateStub<IConversionRule>();
var mockRule2 = MockRepository.GenerateStub<IConversionRule>();
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), new[] { mockRule0, mockRule1, mockRule2 });;
mockRule0.Stub(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Best);
mockRule1.Stub(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Invalid);
mockRule2.Stub(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Default);
Assert.AreEqual(ConversionCost.Best, converter.GetConversionCost(typeof(int), typeof(string)));
}
public void CanConvert_returns_true_if_and_only_if_a_conversion_rule_supports_the_conversion()
{
var mockRule0 = MockRepository.GenerateStub<IConversionRule>();
var mockRule1 = MockRepository.GenerateStub<IConversionRule>();
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), new[] { mockRule0, mockRule1 });;
mockRule0.Stub(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Invalid);
mockRule1.Stub(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Invalid);
mockRule0.Stub(x => x.GetConversionCost(typeof(double), typeof(string), converter)).Return(ConversionCost.Default);
mockRule1.Stub(x => x.GetConversionCost(typeof(double), typeof(string), converter)).Return(ConversionCost.Invalid);
Assert.IsFalse(converter.CanConvert(typeof(int), typeof(string)));
Assert.IsTrue(converter.CanConvert(typeof(double), typeof(string)));
}
public void Convert_caches_the_conversion_so_GetConversionCost_is_only_called_once_for_a_pair_of_types()
{
var mockRule0 = MockRepository.GenerateMock<IConversionRule>();
var mockRule1 = MockRepository.GenerateMock<IConversionRule>();
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), new[] { mockRule0, mockRule1 });
mockRule0.Expect(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Invalid);
mockRule1.Expect(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Return(ConversionCost.Default);
mockRule1.Expect(x => x.Convert(42, typeof(string), converter, true)).Return("42");
mockRule1.Expect(x => x.Convert(53, typeof(string), converter, true)).Return("53");
Assert.AreEqual("42", converter.Convert(42, typeof(string)));
Assert.AreEqual("53", converter.Convert(53, typeof(string)));
mockRule0.VerifyAllExpectations();
mockRule1.VerifyAllExpectations();
}
public void Recursive_conversions_attempts_are_denied()
{
var mockRule = MockRepository.GenerateMock<IConversionRule>();
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), new[] { mockRule });
mockRule.Expect(x => x.GetConversionCost(typeof(int), typeof(string), converter)).Do((GetConversionCostDelegate)delegate
{
Assert.AreEqual(ConversionCost.Invalid, converter.GetConversionCost(typeof(int), typeof(string)));
return ConversionCost.Best;
});
Assert.AreEqual(ConversionCost.Best, converter.GetConversionCost(typeof(int), typeof(string)));
mockRule.VerifyAllExpectations();
}
public void Nullable_target_type_is_translated_before_being_passed_to_the_conversion_rule()
{
var mockRule = MockRepository.GenerateMock<IConversionRule>();
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), new[] { mockRule });
mockRule.Expect(x => x.GetConversionCost(typeof(int), typeof(double), converter)).Return(ConversionCost.Best);
Assert.AreEqual(ConversionCost.Best, converter.GetConversionCost(typeof(int?), typeof(double)));
Assert.AreEqual(ConversionCost.Best, converter.GetConversionCost(typeof(int), typeof(double?)));
Assert.AreEqual(ConversionCost.Best, converter.GetConversionCost(typeof(int?), typeof(double?)));
mockRule.VerifyAllExpectations();
}
public void Custom_conversion()
{
var extensionPoints = new DefaultExtensionPoints();
extensionPoints.CustomConverters.Register<string, Foo>(x => new Foo(Int32.Parse(x)));
var converter = new RuleBasedConverter(extensionPoints, EmptyArray<IConversionRule>.Instance);
var actual = (Foo)converter.Convert("123", typeof(Foo));
Assert.AreEqual(123, actual.Value);
}
public void Nulls_cannot_be_converted_to_non_nullable_ValueTypes()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
converter.Convert(null, typeof(int));
}
public void Nullable_types_are_equivalent_to_non_nullable_types_of_same_underlying_type()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
Assert.AreEqual(ConversionCost.Zero, converter.GetConversionCost(typeof(int?), typeof(int)));
Assert.AreEqual(ConversionCost.Zero, converter.GetConversionCost(typeof(int), typeof(int?)));
Assert.AreEqual(ConversionCost.Zero, converter.GetConversionCost(typeof(int?), typeof(int?)));
}
public void Nulls_remain_rull_during_conversions_to_nullable_ValueTypes()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
Assert.IsNull(converter.Convert(null, typeof(int?)));
}
public void Convert_throws_if_conversion_not_supported()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
converter.Convert("42", typeof(int));
}
public void Convert_returns_same_value_if_types_are_same()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
Assert.AreEqual(42, converter.Convert(42, typeof(int)));
}
public void GetConversionCost_always_returns_zero_if_types_are_same()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
Assert.AreEqual(ConversionCost.Zero, converter.GetConversionCost(typeof(int), typeof(int)));
Assert.AreEqual(ConversionCost.Invalid, converter.GetConversionCost(typeof(int), typeof(string)));
}
public void CanConvert_always_returns_true_if_types_are_same()
{
var converter = new RuleBasedConverter(new DefaultExtensionPoints(), EmptyArray<IConversionRule>.Instance);
Assert.IsTrue(converter.CanConvert(typeof(int), typeof(int)));
Assert.IsFalse(converter.CanConvert(typeof(int), typeof(string)));
}