TestSetPropertyWithBackStoreValueEqualToValueDoesNotSetStoreNorInvokesPropertyChangedEventAndReturnsFalse(
[Values("Hello", "", null)] string currentValue)
{
int invocationCount = 0;
int callbackCount = 0;
BaseViewModelForTest model = new BaseViewModelForTest();
model.PropertyChanged += (s, a) => { invocationCount++; };
void Callback()
{
callbackCount++;
}
string backingStore = currentValue;
string value = currentValue;
bool valueSet = model.InvokeSetProperty(ref backingStore, value, string.Empty, Callback);
Assert.IsFalse(valueSet);
Assert.AreEqual(currentValue, backingStore);
Assert.AreEqual(0, invocationCount);
Assert.AreEqual(0, callbackCount);
}
TestSetPropertyWithBackStoreValueNotEqualToValueSetsStoreAndInvokesPropertyChangedEventAndReturnsTrue(
[Values("Hello", "", null)] string currentValue, [Values("Hello", "", null)] string newValue,
[Values] bool isChangedEventNull, [Values] bool isCallbackNull)
{
// Not valid test case as expecting values to be different
if (currentValue == newValue)
{
return;
}
const string propertyName = "Title";
object sender = null;
PropertyChangedEventArgs args = null;
int invocationCount = 0;
int callbackCount = 0;
int expectedCount = isChangedEventNull ? 0 : 1;
int expectedCallbackCount = isCallbackNull ? 0 : 1;
BaseViewModelForTest model = new BaseViewModelForTest();
if (!isChangedEventNull)
{
model.PropertyChanged += (s, a) =>
{
sender = s;
args = a;
invocationCount++;
};
}
void Callback()
{
callbackCount++;
}
Action callback = isCallbackNull ? (Action)null : Callback;
string backingStore = currentValue;
bool valueSet = model.InvokeSetProperty(ref backingStore, newValue, propertyName, callback);
Assert.IsTrue(valueSet);
Assert.AreEqual(newValue, backingStore);
Assert.AreEqual(expectedCount, invocationCount);
Assert.AreEqual(expectedCallbackCount, callbackCount);
if (!isChangedEventNull)
{
Assert.IsNotNull(sender);
Assert.AreSame(model, sender);
Assert.IsNotNull(args);
Assert.AreEqual(propertyName, args.PropertyName);
}
}