public void TestRouteExists()
{
// Arrange
// null
DirectedGraphNode nullSource = null;
DirectedGraphNode nullDest = new DirectedGraphNode(1);
// source == dest
DirectedGraphNode sameSource = new DirectedGraphNode(1);
DirectedGraphNode sameDest = sameSource;
// common case
DirectedGraphNode commonCaseSource = new DirectedGraphNode(1);
DirectedGraphNode commonCase2 = new DirectedGraphNode(2);
DirectedGraphNode commonCase3 = new DirectedGraphNode(3);
DirectedGraphNode commonCaseDest = new DirectedGraphNode(4);
DirectedGraphNode commonCase5 = new DirectedGraphNode(5);
commonCaseSource.Children.Add(commonCase2);
commonCaseSource.Children.Add(commonCase3);
commonCase2.Children.Add(commonCase3);
commonCase3.Children.Add(commonCaseDest);
// Act
bool nullResult = TreesAndGraphs.RouteExists(nullSource, nullDest);
bool sameResult = TreesAndGraphs.RouteExists(sameSource, sameDest);
bool commonCaseResult = TreesAndGraphs.RouteExists(commonCaseSource, commonCaseDest);
bool commonCaseFalseResult = TreesAndGraphs.RouteExists(commonCaseSource, commonCase5);
// Assert
Assert.IsFalse(nullResult);
Assert.IsTrue(sameResult);
Assert.IsTrue(commonCaseResult);
Assert.IsFalse(commonCaseFalseResult);
}