Merge pull request #63 from Dkendal/fix/rand-space-on-diagonal

Fix random space func

lib/battle_snake/world.ex

@@ -93,10 +93,12 @@ defmodule BattleSnake.World do
     width = world.width - 1
     height = world.height - 1
 
-    domain = Stream.map(0..width, (& &1))
-    range = Stream.map(0..height, (& &1))
-    stream = Stream.zip(domain, range)
-    stream = Stream.map(stream, fn {x, y} -> p(x, y) end)
+    stream = Stream.flat_map(0..width, fn x ->
+      Stream.flat_map(0..height, fn y ->
+        [p(x, y)]
+      end)
+    end)
+
     stream = Stream.filter(stream, fn p ->
       !MapSet.member?(spaces, p)
     end)

test/battle_snake/world_test.exs

@@ -82,14 +82,16 @@ defmodule BattleSnake.WorldTest do
     end
 
     test "does the thing" do
+      food = (for x <- 0..90, y <- 0..90, do: p(x, y))
+
       world = build(:world,
+        snakes: [],
         width: 100,
         height: 100,
-        food: (for x <- 0..90, y <- 0..90, do: p(x, y)))
+        food: food)
 
-      assert {:ok, p(x, y)} = World.rand_unoccupied_space(world)
-      assert_in_delta 90, 99, x
-      assert_in_delta 90, 99, y
+      assert {:ok, v} = World.rand_unoccupied_space(world)
+      assert MapSet.member?(MapSet.new(food), v) == false
     end
 
     test "returns an error if there is no space" do