[InlineData(-2)] // -2*
public void NodWithWithSignH(int h)
{
FiniteDifference goodDifference = FiniteDifference.GetFiniteDifferenceByOrderAndMinH(0, h);
string s = $"u(x{h:+0;-0}*h)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
}
// check parsing simple du
public void Order1CheckWithoutH()
{
FiniteDifference goodDifference = FiniteDifference.GetFiniteDifferenceByOrder(1);
string s = "du(x)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
}
// check simple u(x)
public void NodNoH()
{
FiniteDifference goodDifference = FiniteDifference.GetFiniteDifferenceByOrder(0);
string s = "u(x)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
}
// check parsing d^nu and dnu
public void OrderCheckWithoutH(int order)
{
FiniteDifference goodDifference = FiniteDifference.GetFiniteDifferenceByOrder(order);
// check d^nu
string s = $"d^{order}u(x)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
// check dnu
s = $"d{order}u(x)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
}
// check error in argument
public void ArgsErrors()
{
Assert.Throws <OverflowException>(() => FiniteDifference.Parse("u(x+242342342343*h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u(x+h"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("ux( h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u( h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u(x h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u(x+*h"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u(x -432fe3 h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("u(x -43 3 h)"));
Assert.NotNull(FiniteDifference.Parse("u ( x -4323 * h ) "));
}
// check if order parsing throws exceptions on errors
public void OrderErrors()
{
Assert.Throws <OverflowException>(() => FiniteDifference.Parse("d^43245u(x)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("du"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("ddu(x)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse(" d^u(x)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("d^^2u(x)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse(" d^ 2 2u(x)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse(" d^ - 2u(x)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("ud(x"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("^d2u(x)"));
Assert.Null(FiniteDifference.Parse(" d ^ -2 u ( x -4323 * h ) "));
Assert.NotNull(FiniteDifference.Parse(" d 32 u ( x -4323 * h ) "));
}
// integration test of parsing to check correctness of all parts of parsing
public void OrderAndArgChecks()
{
// check different orders with not null arg
Assert.Equal(FiniteDifference.Parse(" d ^ 21 u ( x - 3h)"),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(21, -3));
Assert.Equal(FiniteDifference.Parse(" d 21 u ( x - 3h)"),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(21, -3));
Assert.Equal(FiniteDifference.Parse(" d u ( x - 3h)"),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(1, -3));
Assert.Equal(FiniteDifference.Parse(" u ( x - 3h)"),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(0, -3));
Assert.Equal(FiniteDifference.Parse(" d ^ -21 u ( x - 3h)"), null);
Assert.Equal(FiniteDifference.Parse(" d -21 u ( x - 3h)"), null);
// check different args with not null orders
Assert.Equal(FiniteDifference.Parse(" d ^ 21 u ( x - h)"),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(21, -1));
Assert.Equal(FiniteDifference.Parse(" d u ( x + h ) "),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(1, 1));
Assert.Equal(FiniteDifference.Parse(" d ^ 21 u ( x + 24 h)"),
FiniteDifference.GetFiniteDifferenceByOrderAndMinH(21, 24));
// check u absence error
Assert.Throws <FormatException>(() => FiniteDifference.Parse("d2(x+2h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("d(x+2h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("(x+2h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("(x)"));
// check args errors with good nont null orders
Assert.Throws <OverflowException>(() => FiniteDifference.Parse(" d^ 5u(x + 24243243242432 h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("d2u(x 2h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse(" d 2u(x + 2 2h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("d^ 11 u(x - - 2h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("d 2u(xh)"));
// check order errors with good nont null args
Assert.Throws <OverflowException>(() => FiniteDifference.Parse(" d 513244u(x+23h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("ddu(x -21h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("2u(x+h)"));
Assert.Throws <FormatException>(() => FiniteDifference.Parse("^1u(x-h)"));
}
// check for u(x-h), u(x+h), u(x-0*h)
public void NodWithHNoNumber()
{
// -0
FiniteDifference goodDifference = FiniteDifference.GetFiniteDifferenceByOrderAndMinH(0, 0);
string s = "u(x-0*h)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
// -h
goodDifference = FiniteDifference.GetFiniteDifferenceByOrderAndMinH(0, -1);
s = "u(x-h)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
// +h
goodDifference = FiniteDifference.GetFiniteDifferenceByOrderAndMinH(0, 1);
s = "u(x+h)";
Assert.True(FiniteDifference.Parse(s) == goodDifference);
}