SolvingChess

I started this project to learn F#. My goal is to create a very basic chess puzzle solver.

Current version is good enough to solve this problems:

[<Test>]
let ``puzzle 01``() =
    let startpos = { 
        EmptyBoard with 
                    WhiteKing = F7;
                    WhitePawns = F5 ||| G6;
                    WhiteKnights = G4;
                    BlackKing = H8;
                    BlackPawns = G7 ||| F6
    }

    let mateline = (findMate startpos 0 5)
    Assert.True(mateline <> None)

    let expected = [| N G4 H6; p G7 H6; p G6 G7; K H8 H7; p G7 G8 |]
    let current = mateline.Value

    Assert.AreEqual(expected, current)

[<Test>]
let ``puzzle 02``() =
    let startpos = { 
        EmptyBoard with 
                    WhiteKing = H1;
                    WhitePawns = A2 ||| C3 ||| D4 ||| F4 ||| H2;
                    WhiteQueens = G5;
                    WhiteBishops = G6;
                    WhiteRooks = H5;
                
                    BlackKing = G7;
                    BlackPawns = A7 ||| B6 ||| C7 ||| D5;
                    BlackKnights = G4 ||| H6;
                    BlackRooks = A8 ||| F8;

                    SideToMove = White
    }

    let mateline = (findMate startpos 0 8)
    Assert.True(mateline <> None)

    let expected = [| B G6 F5; K G7 H8; R H5 H6; N G4 H6; Q G5 H6; K H8 G8; Q H6 H7 |]
    let current = mateline.Value

    Assert.AreEqual(expected, current)

[<Test>]
let ``puzzle 03``() =
    let startpos = { 
        EmptyBoard with 
                    WhiteKing = G1;
                    WhitePawns = A3 ||| B4 ||| C3 ||| D4 ||| E4 ||| F5 ||| G2 ||| H3;
                    WhiteQueens = F2;
                    WhiteBishops = E3 ||| H5;
                    WhiteRooks = D1 |||D3;
                    WhiteKnights = G3 ||| G4;
                
                    BlackKing = H7;
                    BlackPawns = A4 ||| B5 ||| C7 ||| D6 ||| E5 ||| F6 ||| G5 ||| H6;
                    BlackQueens = F8;
                    BlackBishops = B7 ||| G7;
                    BlackRooks = B8 ||| H8;
                    BlackKnights = C6 ||| D7;

                    SideToMove = White
    }

    let mateline = (findMate startpos 0 8)
    Assert.True(mateline <> None)

    let expected = [| B H5 G6; K H7 G8; Q F2 A2; p D6 D5; Q A2 D5; Q F8 F7; Q D5 F7 |]
    let current = mateline.Value

    Assert.AreEqual(expected, current)

Feel free to suggest code improvements. I will work to make it better. ;)