Please write Ruby code -- a class or three -- that models a game of chess. It doesn't need to decide what move to make next, just to allow an imaginary UI (which we won't develop in this exercise) to start with a standard starting board and pieces, ask whether a proposed move is valid (e.g. a pawn can only move one space forward where the meaning of "forward" depends on the pawn's color) and make moves. It doesn't need to persist anything. To start off, just implement moves and captures by pawns. Ignore en passant captures.
Write the class test-driven with rspec or Cucumber. Refactor it until it's clean enough to eat on. Put the results on github and send me the URL. If you have any questions please ask. Those instructions are ideal, so do whatever you think is appropriate and have time for. The point is for me to see how you code and test, not to test your knowledge of specific technologies.