public void GivenMultiLineHelloWorldShouldIgnoreNonOpChars()
{
//Arrange
var input = @"[ This program prints 'Hello World!' and a newline to the screen, its
length is 106 active command characters. [It is not the shortest.]
This loop is an 'initial comment loop', a simple way of adding a comment
to a BF program such that you don't have to worry about any command
characters. Any '.', ',', '+', '-', '<' and '>' characters are simply
ignored, the '[' and ']' characters just have to be balanced. This
loop and the commands it contains are ignored because the current cell
defaults to a value of 0; the 0 value causes this loop to be skipped.
]
++++++++ Set Cell #0 to 8
[
>++++ Add 4 to Cell #1; this will always set Cell #1 to 4
[ as the cell will be cleared by the loop
>++ Add 2 to Cell #2
>+++ Add 3 to Cell #3
>+++ Add 3 to Cell #4
>+ Add 1 to Cell #5
<<<<- Decrement the loop counter in Cell #1
] Loop till Cell #1 is zero; number of iterations is 4
>+ Add 1 to Cell #2
>+ Add 1 to Cell #3
>- Subtract 1 from Cell #4
>>+ Add 1 to Cell #6
[<] Move back to the first zero cell you find; this will
be Cell #1 which was cleared by the previous loop
<- Decrement the loop Counter in Cell #0
] Loop till Cell #0 is zero; number of iterations is 8
The result of this is:
Cell No : 0 1 2 3 4 5 6
Contents: 0 0 72 104 88 32 8
Pointer : ^
>>. Cell #2 has value 72 which is 'H'
>---. Subtract 3 from Cell #3 to get 101 which is 'e'
+++++++..+++. Likewise for 'llo' from Cell #3
>>. Cell #5 is 32 for the space
<-. Subtract 1 from Cell #4 for 87 to give a 'W'
<. Cell #3 was set to 'o' from the end of 'Hello'
+++.------.--------. Cell #3 for 'rl' and 'd'
>>+. Add 1 to Cell #5 gives us an exclamation point
>++. and finally a newline from Cell #6";
var sut = new BrainFuckInterpreter(input, "");
//Act
var actual = sut.Run();
var expected = "Hello World!\n";
//Assert
Assert.AreEqual(expected, actual);
}
public void Given0TerminatedInputStringShouldReturnSameString()
{
//Arrange
var sut = new BrainFuckInterpreter(",[.[-],]", "Codewars" + char.ConvertFromUtf32(0));
//Act
var actual = sut.Run();
var expected = "Codewars";
//Assert
Assert.AreEqual(expected, actual);
}
public void Given2NumberInputsShouldReturnProduct()
{
//Arrange
var sut = new BrainFuckInterpreter(",>,<[>[->+>+<<]>>[-<<+>>]<<<-]>>.", char.ConvertFromUtf32(8) + char.ConvertFromUtf32(9));
//Act
var actual = sut.Run();
var expected = char.ConvertFromUtf32(72);
//Assert
Assert.AreEqual(expected, actual);
}
public void EmptyProgramNonEmptyInputShouldReturnEmptyString()
{
//Arrange
var sut = new BrainFuckInterpreter("", "NOT EMPTY");
//Act
var actual = sut.Run();
var expected = "";
//Assert
Assert.AreEqual(expected, actual);
}