Adds basic test per Derek's question

tests/Spec/Nri/Ui/Switch.elm

@@ -0,0 +1,45 @@
+module Spec.Nri.Ui.Switch exposing (spec)
+
+import Accessibility.Widget as Widget
+import Html.Styled as HtmlStyled
+import Nri.Ui.Switch.V1 as Switch
+import ProgramTest exposing (..)
+import Test exposing (..)
+import Test.Html.Selector as Selector
+
+
+spec : Test
+spec =
+    describe "Nri.Ui.Switch.V1"
+        [ test "it works" <|
+            \() ->
+                program
+                    [ Switch.label (HtmlStyled.text "Switch")
+                    , Switch.onSwitch identity
+                    , Switch.id "switch"
+                    ]
+                    True
+                    -- switch starts with aria-checked=true and displays the label
+                    |> ensureViewHas
+                        [ Selector.attribute (Widget.checked (Just True))
+                        , Selector.text "Switch"
+                        ]
+                    -- user can click the first switch
+                    |> check "switch" "Switch" False
+                    -- the switch now has aria-checked=false
+                    |> ensureViewHas
+                        [ Selector.attribute (Widget.checked (Just False))
+                        , Selector.text "Switch"
+                        ]
+                    |> done
+        ]
+
+
+program : List (Switch.Attribute Bool) -> Bool -> ProgramTest Bool Bool ()
+program attributes init =
+    ProgramTest.createSandbox
+        { init = init
+        , update = \msg model -> msg
+        , view = \isOpen -> Switch.view attributes isOpen |> HtmlStyled.toUnstyled
+        }
+        |> ProgramTest.start ()