Validate non empty string segment

src/UrlParser.elm

@@ -57,7 +57,12 @@ type alias State value =
 -}
 string : Parser (String -> a) a
 string =
-  custom "STRING" Ok
+  custom "STRING" <|
+    \segment ->
+      if String.isEmpty segment then
+        Err "Empty string"
+      else
+        Ok segment
 
 
 {-| Parse a segment of the path as an `Int`.
@@ -93,14 +98,11 @@ s str =
 
 
 {-| Create a custom path segment parser. Here is how it is used to define the
-`int` and `string` parsers:
+`int` parser:
 
     int =
       custom "NUMBER" String.toInt
 
-    string =
-      custom "STRING" Ok
-
 You can use it to define something like “only CSS files” like this:
 
     css : Parser (String -> a) a

tests/Tests.elm

@@ -6,7 +6,6 @@ import Test exposing (..)
 import Expect
 
 
-
 -- TESTS
 
 
@@ -17,34 +16,58 @@ all =
         ]
 
 
+testParsing : List Test
 testParsing =
-    [ parserTest "Home" "" HomeRoute
-    , parserTest "About" "about" AboutRoute
-    , parserTest "Token" "token/abc" (TokenRoute "abc")
-    , parserTest "Users" "users" (UsersRoutes UsersRoute)
-    , parserTest "User" "users/2" (UsersRoutes (UserRoute 2))
-    , parserTest "Edit" "users/2/edit" (UsersRoutes (UserEditRoute 2))
+    [ parserTest "Home" "" <| Ok HomeRoute
+    , parserTest "About" "about" <| Ok AboutRoute
+    , parserTest "Token" "token/abc" <| Ok (TokenRoute "abc")
+    , parserTest "Token (missing ID)" "token/" <| Err "missing token segment"
+    , parserTest "Users" "users" <| Ok (UsersRoutes UsersRoute)
+    , parserTest "User" "users/2" <| Ok (UsersRoutes (UserRoute 2))
+    , parserTest "Edit" "users/2/edit" <| Ok (UsersRoutes (UserEditRoute 2))
     ]
 
 
-parserTest name path expectedRoute =
-    describe name
-        [ test (name ++ " in path") <|
-            \() ->
-                Expect.equal
-                    (Just expectedRoute)
-                    (parsePath routeParser { newLocation | pathname = "/" ++ path })
-        , test (name ++ " in hash") <|
-            \() ->
-                Expect.equal
-                    (Just expectedRoute)
-                    (parseHash routeParser { newLocation | hash = "#/" ++ path })
-        , test (name ++ "in hash without leading slash") <|
-            \() ->
-                Expect.equal
-                    (Just expectedRoute)
-                    (parseHash routeParser { newLocation | hash = "#" ++ path })
-        ]
+parserTest : String -> String -> Result a MainRoute -> Test
+parserTest name path expectedRouteResult =
+    case expectedRouteResult of
+        Ok expectedRoute ->
+            describe name
+                [ test (name ++ " in path") <|
+                    \() ->
+                        Expect.equal
+                            (Just expectedRoute)
+                            (parsePath routeParser { newLocation | pathname = "/" ++ path })
+                , test (name ++ " in hash") <|
+                    \() ->
+                        Expect.equal
+                            (Just expectedRoute)
+                            (parseHash routeParser { newLocation | hash = "#/" ++ path })
+                , test (name ++ " in hash without leading slash") <|
+                    \() ->
+                        Expect.equal
+                            (Just expectedRoute)
+                            (parseHash routeParser { newLocation | hash = "#" ++ path })
+                ]
+
+        Err _ ->
+            describe name
+                [ test (name ++ " in path") <|
+                    \() ->
+                        Expect.equal
+                            Nothing
+                            (parsePath routeParser { newLocation | pathname = "/" ++ path })
+                , test (name ++ " in hash") <|
+                    \() ->
+                        Expect.equal
+                            Nothing
+                            (parseHash routeParser { newLocation | hash = "#/" ++ path })
+                , test (name ++ "in hash without leading slash") <|
+                    \() ->
+                        Expect.equal
+                            Nothing
+                            (parseHash routeParser { newLocation | hash = "#" ++ path })
+                ]
 
 
 
@@ -73,17 +96,20 @@ type MainRoute
 -- PARSERS
 
 
+routeParser : Parser (MainRoute -> c) c
 routeParser =
     oneOf mainMatchers
 
 
+usersMatchers : List (Parser (UserRoute -> c) c)
 usersMatchers =
     [ map UserEditRoute (int </> s "edit")
     , map UserRoute (int)
     , map UsersRoute top
     ]
 
 
+mainMatchers : List (Parser (MainRoute -> c) c)
 mainMatchers =
     [ map HomeRoute top
     , map AboutRoute (s "about")

tests/elm-package.json

@@ -11,9 +11,8 @@
     "dependencies": {
         "elm-lang/core": "5.0.0 <= v < 6.0.0",
         "elm-lang/http": "1.0.0 <= v < 2.0.0",
-        "elm-community/elm-test": "3.0.0 <= v < 4.0.0",
-        "elm-lang/navigation": "2.0.0 <= v < 3.0.0",
-        "rtfeldman/node-test-runner": "3.0.0 <= v < 4.0.0"
+        "elm-community/elm-test": "4.0.0 <= v < 5.0.0",
+        "elm-lang/navigation": "2.0.0 <= v < 3.0.0"
     },
     "elm-version": "0.18.0 <= v < 0.19.0"
 }