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

1 files changed, 19 insertions, 0 deletions

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)]
+    ]
+  ]