passing empty params test

src/parser.fs

@@ -354,10 +354,12 @@ let internal toKeyValuePair (segment: string) =
 #endif
 
 let parseParams (querystring: string) =
-    querystring.Substring(1).Split('&')
-    |> Seq.map toKeyValuePair
-    |> Seq.choose id
-    |> Map.ofSeq
+    if System.String.IsNullOrEmpty querystring then Map.empty
+    else
+        querystring.Split('&')
+        |> Seq.map toKeyValuePair
+        |> Seq.choose id
+        |> Map.ofSeq
 
 (**
 #### Parsers
@@ -367,7 +369,7 @@ let parseUrl (parser: Parser<_,_>) (url:string) =
     let pos = url.IndexOf "?"
     if pos >= 0 then
         let path = url.Substring(0,pos)
-        let search = url.Substring(pos)
+        let search = url.Substring(pos+1)
         parse parser path (parseParams search)
     else
         parse parser url Map.empty

tests/Tests.fs

@@ -13,6 +13,11 @@ type Routes =
 let curry3 f a b c = f (a,b,c)
 
 open NUnit.Framework
+[<Test>]
+let ``empty query string`` () =
+  let parser = s "id" </> i32 <?> stringParam "one" <?> stringParam "two" |> map (curry3 IntAndTwoStringOptions)
+  parseUrl parser "id/123?" =! Some (IntAndTwoStringOptions (123, None, None))
+
 [<Test>]
 let ``parses subroute and multiple params`` () =
   let parser = s "id" </> i32 <?> stringParam "one" <?> stringParam "two" |> map (curry3 IntAndTwoStringOptions)