Set string props to empty on removal (#13)

* Set string props to empty on removal

* Correct version constraint

Author: natefaubion

bower.json

@@ -30,7 +30,8 @@
     "purescript-maybe": "^2.0.1",
     "purescript-unsafe-coerce": "^2.0.0",
     "purescript-bifunctors": "^2.0.0",
-    "purescript-refs": "^2.0.0"
+    "purescript-refs": "^2.0.0",
+    "purescript-foreign": "^3.0.1"
   },
   "devDependencies": {
     "purescript-psci-support": "^2.0.0",

src/Halogen/VDom/DOM/Prop.purs

@@ -16,6 +16,7 @@ import Control.Monad.Eff.Ref as Ref
 import Data.Maybe (Maybe(..), maybe)
 import Data.StrMap as StrMap
 import Data.Nullable (toNullable)
+import Data.Foreign (typeOf)
 import Data.Function.Uncurried as Fn
 import Data.Tuple (Tuple(..), fst, snd)
 import DOM (DOM)
@@ -190,4 +191,6 @@ unsafeGetProperty = Util.unsafeGetAny
 
 removeProperty ∷ ∀ eff. Fn.Fn2 String DOM.Element (Eff (dom ∷ DOM | eff) Unit)
 removeProperty = Fn.mkFn2 \key el →
-  Fn.runFn3 Util.unsafeSetAny key Util.jsUndefined el
+  case typeOf (Fn.runFn2 Util.unsafeGetAny key el) of
+    "string" → Fn.runFn3 Util.unsafeSetAny key "" el
+    _        → Fn.runFn3 Util.unsafeSetAny key Util.jsUndefined el