Cost must not be negative

1 files changed, 5 insertions, 3 deletions

diff --git a/src/client/Utils/Validation.elm b/src/client/Utils/Validation.elm
index 0c1773e..b9bccb3 100644
--- a/src/client/Utils/Validation.elm
+++ b/src/client/Utils/Validation.elm
@@ -12,10 +12,12 @@ validateNonEmpty message str =
    then Err message
    else Ok str
 
-validateNumber : String -> String -> Result String Int
-validateNumber message str =
+validateNumber : String -> (Int -> Bool) -> String -> Result String Int
+validateNumber message numberForm str =
   case readInt str of
     Just number ->
-      Ok number
+      if numberForm number
+        then Ok number
+        else Err message
     Nothing ->
       Err message