fix(xanthous): Only use alphabetic chars for menu items r/2682

Previously, we were using `smallestNotIn` for selecting new characters
for menu items with duplicate chatacters - this uses the 'Bounded'
instance for the type, which for Char meant the first character we would
always select was \NUL - making it look like the menu item had no
character, and making it impossible to actually select the menu item.
This introduces an AlphaChar newtype, which is a wrapper around Char
whose Bounded and Enum instances only use alphabetic characters (a-ZA-Z)
and uses that for menu characters instead.

Change-Id: If34ed9e9ce84f2bcb1cb87432cc6273f40b69f72
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3229
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI

3 files changed, 24 insertions, 0 deletions

diff --git a/users/grfn/xanthous/test/Spec.hs b/users/grfn/xanthous/test/Spec.hs
index 85f49fd07c91..dfecfbdd21c5 100644
--- a/users/grfn/xanthous/test/Spec.hs
+++ b/users/grfn/xanthous/test/Spec.hs
@@ -13,6 +13,7 @@ import qualified Xanthous.Entities.RawsSpec
 import qualified Xanthous.Entities.CharacterSpec
 import qualified Xanthous.GameSpec
 import qualified Xanthous.Game.StateSpec
+import qualified Xanthous.Game.PromptSpec
 import qualified Xanthous.Generators.Level.UtilSpec
 import qualified Xanthous.MessageSpec
 import qualified Xanthous.Messages.TemplateSpec
@@ -40,6 +41,7 @@ test = testGroup "Xanthous"
   , Xanthous.Entities.CharacterSpec.test
   , Xanthous.GameSpec.test
   , Xanthous.Game.StateSpec.test
+  , Xanthous.Game.PromptSpec.test
   , Xanthous.Generators.Level.UtilSpec.test
   , Xanthous.MessageSpec.test
   , Xanthous.Messages.TemplateSpec.test
diff --git a/users/grfn/xanthous/test/Xanthous/Game/PromptSpec.hs b/users/grfn/xanthous/test/Xanthous/Game/PromptSpec.hs
new file mode 100644
index 000000000000..d7a3df4acafa
--- /dev/null
+++ b/users/grfn/xanthous/test/Xanthous/Game/PromptSpec.hs
@@ -0,0 +1,19 @@
+--------------------------------------------------------------------------------
+module Xanthous.Game.PromptSpec (main, test) where
+--------------------------------------------------------------------------------
+import           Test.Prelude
+--------------------------------------------------------------------------------
+import           Xanthous.Game.Prompt
+--------------------------------------------------------------------------------
+
+main :: IO ()
+main = defaultMain test
+
+test :: TestTree
+test = testGroup "Xanthous.Game.PromptSpec"
+  [ testGroup "mkMenuItems"
+    [ testCase "with duplicate items"
+      $ mkMenuItems @[_] [('a', MenuOption @Int "a" 1), ('a', MenuOption "a" 2)]
+        @?= mapFromList [('a', MenuOption "a" 1), ('b', MenuOption "a" 2)]
+    ]
+  ]
diff --git a/users/grfn/xanthous/test/Xanthous/UtilSpec.hs b/users/grfn/xanthous/test/Xanthous/UtilSpec.hs
index 0d6b718bc351..684a03b2c7a0 100644
--- a/users/grfn/xanthous/test/Xanthous/UtilSpec.hs
+++ b/users/grfn/xanthous/test/Xanthous/UtilSpec.hs
@@ -40,4 +40,7 @@ test = testGroup "Xanthous.Util"
     , testProperty "the result is the right length" $ \(xs :: [Int]) p ->
         length (removeFirst p xs) `elem` [length xs, length xs - 1]
     ]
+  , testGroup "AlphaChar"
+    [ testCase "succ 'z'" $ succ (AlphaChar 'z') @?= AlphaChar 'A'
+    ]
   ]