public void TestSimpleUnchanged()
{
var w = Mutable.From(0);
w.PropertyChanged += (s, e) => { throw new Exception("Shouldn't fire Changed event if value is unchanged"); };
w.Value = 0;
}
public void TestRecursion()
{
var w = Mutable.From(0);
// Not okay to set it to a different value (hence expected exception)
w.PropertyChanged += (s, e) => w.Value++;
w.Value++;
}
public void TestReentrance()
{
var w = Mutable.From(0);
// Okay to assign to writeable that just changed as long as it's the same (new) value
w.PropertyChanged += (s, e) => w.Value = 1;
w.Value++;
}
public void TestSimpleChanged()
{
var w = Mutable.From(0);
var changed = false;
w.PropertyChanged += (s, e) => changed = true;
w.Value = 1;
Assert.IsTrue(changed);
}
public void TestNotification()
{
var x = Mutable.From(1);
var y = Mutable.From(2);
var z = Computed.From(() => x.Value + y.Value);
Assert.AreEqual(3, z.Value);
Assert.AreEqual(false, z.IsActive);
x.Value = 3;
Assert.AreEqual(5, z.Value);
Assert.AreEqual(false, z.IsActive);
var p = Computed.From(() => z.Value * 2);
Assert.AreEqual(10, p.Value);
Assert.AreEqual(false, p.IsActive);
Assert.AreEqual(false, z.IsActive);
var notified = 0;
PropertyChangedEventHandler changed = (s, e) => notified++;
p.PropertyChanged += changed;
Assert.AreEqual(true, p.IsActive);
Assert.AreEqual(true, z.IsActive);
Assert.AreEqual(0, notified);
y.Value = 1;
Assert.AreEqual(true, p.IsActive);
Assert.AreEqual(true, z.IsActive);
Assert.AreEqual(1, notified);
Assert.AreEqual(8, p.Value);
p.PropertyChanged -= changed;
Assert.AreEqual(false, p.IsActive);
Assert.AreEqual(false, z.IsActive);
Assert.AreEqual(1, notified);
Assert.AreEqual(8, p.Value);
x.Value = 1;
Assert.AreEqual(false, p.IsActive);
Assert.AreEqual(false, z.IsActive);
Assert.AreEqual(1, notified);
Assert.AreEqual(4, p.Value);
}
public void TestCustomEquality()
{
// Default comparison uses equals method
var changed = false;
var w = Mutable.From(new[] { 5, 20, 13 });
w.PropertyChanged += (s, e) => changed = true;
w.Value = new[] { 5, 20, 13 }; // even though contents are same, still counts as changed
Assert.IsTrue(changed);
changed = false;
// Replace with order-agnostic sequence comparison
w.EqualityComparer = (a, b) => a.OrderBy(i => i).SequenceEqual(b.OrderBy(i => i));
// Same contents in different order, no Changed event
w.Value = new[] { 5, 13, 20 };
Assert.IsFalse(changed);
// Change one value and it triggers Changed
w.Value = new[] { 5, 3, 20 };
Assert.IsTrue(changed);
}