require 'rubygems'
require 'test/unit'
require 'shoulda'
require 'sudoku'
class CellTest < Test::Unit::TestCase
def create_group_with(cell, *numbers)
g = Group.new
g << cell
numbers.each do |n|
c = Cell.new
c.number = n
g << c
end
g
end
context 'a cell' do
setup do
@cell = Cell.new("C25")
end
should 'know its name' do
assert_equal "C25", @cell.to_s
end
should 'be inspectable' do
assert_equal "C25", @cell.inspect
end
should 'initially have no number' do
assert_nil @cell.number
end
should 'be able to set number' do
@cell.number = 4
assert_equal 4, @cell.number
end
should 'accept a zero as no number' do
@cell.number = 0
assert_nil @cell.number
end
should 'report all numbers are available' do
assert_equal( Set[*(1..9)], @cell.available_numbers )
end
context 'within a group' do
setup do
@group = create_group_with(@cell, 3, 4, 5)
end
should 'report available numbers not in the group' do
assert_equal Set[1, 2, 6, 7, 8, 9], @cell.available_numbers
end
should 'report no available numbers if a number has been assigned' do
@cell.number = 6
assert_equal Set[], @cell.available_numbers
end
end
end
end
class GroupTest < Test::Unit::TestCase
context 'a group of cells' do
setup do
@group = Group.new
end
should 'exist' do
assert_not_nil @group
end
context 'with cells' do
setup do
@cells = (1..10).map { |i| Cell.new("C#{i}") }
@cells.each do |c| @group << c end
end
should 'give a list of numbers' do
assert_equal Set[], @group.numbers
end
context 'with some numbers' do
setup do
@cells[0].number = 3
@cells[3].number = 6
end
should 'give a list of the remaining missing numbers' do
assert_equal [3, 6], @group.numbers.sort
end
end
end
end
end
module Puzzles
Wiki =
"53 7 " +
"6 195 " +
" 98 6 " +
"8 6 3" +
"4 8 3 1" +
"7 2 6" +
" 6 28 " +
" 419 5" +
" 8 79"
Medium =
" 4 7 3 " +
" 85 1 " +
" 15 3 9 " +
"5 7 21 " +
" 6 8 " +
" 81 6 9" +
" 2 4 57 " +
" 7 29 " +
" 5 7 8 "
Evil =
" 53 694 " +
" 3 1 6" +
" 3 " +
"7 9 " +
" 1 3 2 " +
" 2 7" +
" 6 " +
"8 7 5 " +
" 436 81 "
end
class BoardTest < Test::Unit::TestCase
include Puzzles
context 'a board' do
setup do
@board = Board.new
end
should 'be inspectable' do
assert_match %r(^<Board \.{81}>$), @board.inspect
end
should 'initially give all 9 numbers for all cells' do
@board.each do |cell|
assert_equal((1..9).to_a, cell.available_numbers.sort)
end
end
should 'parse a string representation of the puzzle' do
@board.parse(Wiki)
assert_equal "5 3 . . 7 . . . . \n" +
"6 . . 1 9 5 . . . \n" +
". 9 8 . . . . 6 . \n\n" +
"8 . . . 6 . . . 3 \n" +
"4 . . 8 . 3 . . 1 \n" +
"7 . . . 2 . . . 6 \n\n" +
". 6 . . . . 2 8 . \n" +
". . . 4 1 9 . . 5 \n" +
". . . . 8 . . 7 9 \n\n",
@board.to_s
end
should 'solve the Wikipedia Puzzle' do
board = Board.new.parse(Wiki)
board.solve
assert board.solved?
assert_equal "534678912672195348198342567" +
"859761423426853791713924856" +
"961537284287419635345286179",
board.encoding
end
should 'solve the Wikipedia Puzzle with DOS line endings' do
board = Board.new.parse(open("puzzles/wiki_dos.sud") { |f| f.read })
board.solve
assert board.solved?
assert_equal "534678912672195348198342567" +
"859761423426853791713924856" +
"961537284287419635345286179",
board.encoding
end
should 'solve the Medium Puzzle' do
board = Board.new.parse(Medium)
board.solve
assert board.solved?
assert_equal "942187635368594127715236498" +
"593478216476921853281365749" +
"829643571137852964654719382",
board.encoding
end
should 'solve the Evil Puzzle' do
board = Board.new.parse(Evil)
board.solve
assert board.solved?
assert_equal "285376941439125786176849235" +
"752981364618734529394562817" +
"567213498821497653943658172",
board.encoding
end
end
end
class SudokuSolverTest < Test::Unit::TestCase
WikiPuzzleFile = 'puzzles/wiki.sud'
SOLUTION = %{5 3 4 6 7 8 9 1 2
6 7 2 1 9 5 3 4 8
1 9 8 3 4 2 5 6 7
8 5 9 7 6 1 4 2 3
4 2 6 8 5 3 7 9 1
7 1 3 9 2 4 8 5 6
9 6 1 5 3 7 2 8 4
2 8 7 4 1 9 6 3 5
3 4 5 2 8 6 1 7 9}
def redirect_output
old_stdout = $stdout
$stdout = StringIO.new
yield
$stdout.string
ensure
$stdout = old_stdout
end
context 'a solver' do
setup do
@solver = SudokuSolver.new
end
should 'solve a puzzle' do
result = redirect_output do
@solver.run([WikiPuzzleFile])
end
assert_match(/#{SOLUTION}/, result)
end
should 'complain if no file given' do
result = redirect_output do
assert_raise(SystemExit) do
@solver.run([])
end
end
assert_match(/Usage:/, result)
end
end
end
