pad menu selections to same width

src/Mtlstats/Types/Menu.hs

@@ -39,6 +39,7 @@ module Mtlstats.Types.Menu (
 import Lens.Micro ((^.))
 import Lens.Micro.TH (makeLenses)
 
+import Mtlstats.Format
 import Mtlstats.Types
 
 -- | Defines a menu
@@ -65,8 +66,15 @@ makeLenses ''Menu
 makeLenses ''MenuItem
 
 instance Show (Menu a) where
-  show m = m ^. menuTitle ++ "\n\n" ++ items
-    where items = unlines $ map show $ m ^. menuItems
+  show m = unlines
+    $  [ m^.menuTitle
+       , ""
+       ]
+    ++ body
+    where
+      body  = map (left width) items
+      width = maximum $ map length items
+      items = map show $ m^.menuItems
 
 instance Show (MenuItem a) where
   show i = [i ^. miKey] ++ ": " ++ i ^. miDescription

test/Types/MenuSpec.hs

@@ -37,11 +37,11 @@ showSpec :: Spec
 showSpec = describe "show" $
   it "should display correctly" $ let
     menu = Menu "Foo" ()
-      [ MenuItem '1' "Item 1" $ return ()
-      , MenuItem '2' "Item 2" $ return ()
+      [ MenuItem '1' "foo" $ return ()
+      , MenuItem '2' "bar baz" $ return ()
       ]
     expected =
       "Foo\n\n\
-      \1: Item 1\n\
-      \2: Item 2\n"
+      \1: foo    \n\
+      \2: bar baz\n"
     in show menu `shouldBe` expected