public void TestExpressionToInfix() { ExpressionTree tree1 = new ExpressionTree("A1+B1"); string expression1 = "(A1+B1)+C2+D2"; string expression2 = "(4+2-(4-A))"; string expression3 = "(Alpha+4)"; string expression4 = "Bravo"; string expression5 = string.Empty; List <string> infix1 = new List <string> { "(", "A1", "+", "B1", ")", "+", "C2", "+", "D2" }; List <string> infix2 = new List <string> { "(", "4", "+", "2", "-", "(", "4", "-", "A", ")", ")" }; List <string> infix3 = new List <string> { "(", "Alpha", "+", "4", ")" }; List <string> infix4 = new List <string> { "Bravo" }; List <string> infix5 = new List <string> { string.Empty }; Assert.That(infix1, Is.EqualTo(tree1.ConvertExpressionToInfix(expression1)), "Failed on infix1"); Assert.That(infix2, Is.EqualTo(tree1.ConvertExpressionToInfix(expression2)), "Failed on infix2"); Assert.That(infix3, Is.EqualTo(tree1.ConvertExpressionToInfix(expression3)), "Failed on infix3"); Assert.That(infix4, Is.EqualTo(tree1.ConvertExpressionToInfix(expression4)), "Failed on infix4"); Assert.That(infix5, Is.EqualTo(tree1.ConvertExpressionToInfix(expression5)), "Failed on infix5"); }