public void Maybe_should_throw_an_exception_while_trying_to_extract_value_from_nothing()
{
string value = null;
var context = Maybe.ApplyTo(value);
Assert.Throws <NoneException>(() => context.GetValue());
}
public void Maybe_should_lift_null_value_into_the_ctx()
{
string value = null;
var context = Maybe.ApplyTo(value);
Assert.That(context.HasValue(), Is.EqualTo(false));
}
public void Maybe_should_lift_not_null_value_into_the_ctx()
{
const string value = "some string";
var context = Maybe.ApplyTo(value);
Assert.That(context.HasValue(), Is.EqualTo(true));
Assert.That(context.GetValue(), Is.EqualTo(value));
}
public void Maybe_should_get_primary_value_when_extracting_from_something()
{
const string defaultValue = "default value";
string value = "another value";
var context = Maybe.ApplyTo(value);
Assert.That(context.HasValue(), Is.EqualTo(true));
Assert.That(context.GetValueOr(defaultValue), Is.EqualTo(value));
}
public void Maybe_should_fallback_to_default_value_when_extracting_data_from_nothing()
{
const string defaultValue = "default value";
string value = null;
var context = Maybe.ApplyTo(value);
Assert.That(context.HasValue(), Is.EqualTo(false));
Assert.Throws <NoneException>(() => context.GetValue());
Assert.That(context.GetValueOr(defaultValue), Is.EqualTo(defaultValue));
}
public void Maybe_should_be_representable_as_monadic_comprehension()
{
const string defaultString = "__defaultString";
const int defaultInteger = 42;
var ctx = from a in Maybe.ApplyTo(defaultInteger)
from b in Maybe.ApplyTo(defaultString)
select new { Left = a, Right = b };
Assert.That(ctx.HasValue(), Is.EqualTo(true));
Assert.That(ctx.GetValue().Left, Is.EqualTo(defaultInteger));
Assert.That(ctx.GetValue().Right, Is.EqualTo(defaultString));
}
