Add test cases for failing selectors and event triggering

src/TestContext.elm

@@ -16,7 +16,7 @@ module TestContext
 import Expect exposing (Expectation)
 import TestContextInternal as Internal
 import Test.Html.Query
-import Test.Html.Events as Events exposing (Event)
+import Test.Html.Events exposing (Event)
 import Time exposing (Time)
 
 
@@ -70,11 +70,7 @@ expectView context =
 
 simulate : (Test.Html.Query.Single msg -> Test.Html.Query.Single msg) -> Event -> TestContext model msg -> TestContext model msg
 simulate eventTrigger event context =
-    eventTrigger (expectView context)
-        |> Events.simulate event
-        |> Events.eventResult
-        |> Result.map ((flip update) context)
-        |> Result.withDefault (context)
+    Internal.simulate eventTrigger event context
 
 
 done : TestContext model msg -> Expectation

src/TestContextInternal.elm

@@ -14,6 +14,7 @@ module TestContextInternal
         , advanceTime
         , expectModel
         , expectView
+        , simulate
         , done
           -- private to elm-testable
         , error
@@ -37,6 +38,7 @@ import Set exposing (Set)
 import Testable.EffectManager as EffectManager exposing (EffectManager)
 import Testable.Task exposing (fromPlatformTask, Task(..), ProcessId(..))
 import Test.Html.Query
+import Test.Html.Events as Events exposing (Event)
 import Time exposing (Time)
 import WebSocket.LowLevel
 
@@ -901,6 +903,22 @@ expectView context =
             Html.text (report "expectView" context) |> Test.Html.Query.fromHtml
 
 
+simulate : (Test.Html.Query.Single msg -> Test.Html.Query.Single msg) -> Event -> TestContext model msg -> TestContext model msg
+simulate eventTrigger event context =
+    let
+        eventResult =
+            eventTrigger (expectView context)
+                |> Events.simulate event
+                |> Events.eventResult
+    in
+        case eventResult of
+            Ok msg ->
+                update msg context
+
+            Err err ->
+                withContext ((flip error) err) context
+
+
 done : TestContext model msg -> Expectation
 done =
     expect "TestContext.done" (always ()) (always Expect.pass)

tests/ViewTests.elm

@@ -1,12 +1,14 @@
 module ViewTests exposing (all)
 
+import Expect
 import Html
 import Html.Events exposing (onClick)
 import Test exposing (..)
 import Test.Html.Events as Events
 import Test.Html.Query as Query
 import Test.Html.Selector as Selector
 import TestContext exposing (TestContext)
+import TestContextInternal
 
 
 htmlProgram : TestContext (List String) String
@@ -27,6 +29,16 @@ htmlProgram =
         |> TestContext.start
 
 
+expectError : String -> TestContext model msg -> Expect.Expectation
+expectError expectedError context =
+    case context of
+        TestContextInternal.TestContext _ ->
+            Expect.fail "TestContext should have an error an it doesn't"
+
+        TestContextInternal.TestError { error } ->
+            Expect.equal expectedError error
+
+
 all : Test
 all =
     describe "View"
@@ -48,4 +60,14 @@ all =
                     |> TestContext.simulate (Query.find [ Selector.tag "button" ]) Events.Click
                     |> TestContext.expectView
                     |> Query.has [ Selector.tag "p" ]
+        , test "fails when triggering events on a not found element" <|
+            \() ->
+                htmlProgram
+                    |> TestContext.simulate (Query.find [ Selector.tag "foo" ]) Events.Click
+                    |> expectError "Query.find always expects to find 1 element, but it found 0 instead."
+        , test "fails when triggersingevents on an element that does not handle that event" <|
+            \() ->
+                htmlProgram
+                    |> TestContext.simulate (Query.find [ Selector.tag "button" ]) Events.DoubleClick
+                    |> expectError "Failed to decode string"
         ]