Test update and view function

tests/PhotoGrooveTest.elm

@@ -1,16 +1,20 @@
 module PhotoGrooveTest exposing (..)
 
-import Expect exposing (Expectation)
+import Expect
-import Fuzz exposing (Fuzzer, int, list, string)
+import Fuzz
+import Html.Attributes as Attr
 import Json.Decode as J
-import Json.Encode as Encode exposing (Value)
+import Json.Encode as Encode
-import PhotoGroove.Internal as Testee
+import PhotoGroove.Internal as Testee exposing (FilterType(..), FilterValues, Message(..), Photo, filterTypeToName, initialModel)
 import Test exposing (..)
+import Test.Html.Query as Query
+import Test.Html.Selector exposing (attribute, tag)
 
 
 suite : Test
 suite =
-    describe "photoDecoder"
+    concat
+        [ describe "photoDecoder"
             [ fuzz2 Fuzz.string Fuzz.int "title always defaults to '(untitled)'" <|
                 \url size ->
                     [ ( "url", Encode.string url )
@@ -21,3 +25,83 @@ suite =
                         |> Result.map .title
                         |> Expect.equal (Ok "(untitled)")
             ]
+        , describe "update"
+            [ describe "slider event sets filter value"
+                [ sliderTest Hue .hue
+                , sliderTest Ripple .ripple
+                , sliderTest Noise .noise
+                ]
+            , test "when photos are loaded, the first one gets selected" <|
+                \_ ->
+                    Testee.initialModel
+                        |> Testee.update (GotPhotos (Ok <| [ photoFromUrl "1.jpg" ]))
+                        |> Tuple.first
+                        |> .status
+                        |> selectedUrl
+                        |> Expect.equal (Just "1.jpg")
+            ]
+        , describe "view"
+            [ test "no photos, no thumbnails" <|
+                \_ ->
+                    Testee.initialModel
+                        |> Testee.view
+                        |> Query.fromHtml
+                        |> Query.findAll [ tag "img" ]
+                        |> Query.count (Expect.equal 0)
+            , fuzz (Fuzz.intRange 1 5) "URLs render as thumbnails" <|
+                \count ->
+                    let
+                        urls : List String
+                        urls =
+                            List.range 1 count
+                                |> List.map (\num -> String.fromInt num ++ ".png")
+
+                        photos =
+                            List.map photoFromUrl urls
+
+                        checks =
+                            List.map thumbnailRendered urls
+                    in
+                    { initialModel | status = Testee.Loaded photos "" }
+                        |> Testee.view
+                        |> Query.fromHtml
+                        |> Expect.all checks
+            ]
+        ]
+
+
+sliderTest : FilterType -> (FilterValues -> Int) -> Test
+sliderTest filterType value =
+    fuzz Fuzz.int (filterTypeToName filterType) <|
+        \amount ->
+            Testee.initialModel
+                |> Testee.update (ChangedFilter filterType amount)
+                |> Tuple.first
+                |> .filterValues
+                |> value
+                |> Expect.equal amount
+
+
+thumbnailRendered : String -> Query.Single msg -> Expect.Expectation
+thumbnailRendered url query =
+    query
+        |> Query.findAll [ tag "img", attribute (Attr.src (Testee.urlPrefix ++ url)) ]
+        |> Query.count (Expect.atLeast 1)
+
+
+photoFromUrl : String -> Photo
+photoFromUrl url =
+    { url = url, size = 0, title = "" }
+
+
+selectedUrl : Testee.Status -> Maybe String
+selectedUrl status =
+    case status of
+        Testee.Loading ->
+            Nothing
+
+        Testee.Loaded _ url ->
+            Just url
+
+        Testee.Errored _ ->
+            Nothing