V2.2.1

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
       matrix:
         # Run on Mac and Linux, for multiple Node versions
         os: [macos-latest, ubuntu-latest]
-        node: ['8', '10', '12', '14']
+        node: ['16', '18', '20', '22', '24']
 
     env:
       ELM_HOME: '${{ github.workspace }}/elm-home'
@@ -32,7 +32,7 @@ jobs:
 
       # Install elm and cache ELM_HOME
       - name: Install elm
-        uses: mpizenberg/elm-tooling-action@v1.2
+        uses: mpizenberg/elm-tooling-action@v1.7
         with:
           cache-key: tests-${{ matrix.os }}-node${{ matrix.node }}-0
           cache-restore-key: tests-${{ matrix.os }}-node${{ matrix.node }}
@@ -50,7 +50,7 @@ jobs:
 
       # Install elm-format
       - name: Install elm-format
-        uses: mpizenberg/elm-tooling-action@v1.2
+        uses: mpizenberg/elm-tooling-action@v1.7
         with:
           cache-key: format-${{ matrix.os }}-node${{ matrix.node }}-0
           cache-restore-key: format-${{ matrix.os }}-node${{ matrix.node }}

CHANGELOG.md

@@ -1,24 +1,25 @@
 ## Releases
 
-| Version                                                                              | Notes                                                                                                                                              |
-| ------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------- |
-| [**2.2.0**](https://github.com/elm-explorations/test/tree/2.2.0)                     | `Fuzz`: Add `Fuzz.filterMap`
-| [**2.1.2**](https://github.com/elm-explorations/test/tree/2.1.2)                     | `Fuzz`: Remove arbitrary limit on amount of randomness drawn
-| [**2.1.1**](https://github.com/elm-explorations/test/tree/2.1.1)                     | `Test.Html.Query`: Change how boolean attributes are rendered
-| [**2.1.0**](https://github.com/elm-explorations/test/tree/2.1.0)                     | Add `Test.Html.Selector.exactText`                                                                                                                           |
-| [**2.0.1**](https://github.com/elm-explorations/test/tree/2.0.1)                     | Documentation fixes                                                                                                                                |
-| [**2.0.0**](https://github.com/elm-explorations/test/tree/2.0.0)                     | Reimplements fuzzing+shrinking, adds fuzzer distribution reporting. Most notably readds `Fuzz.andThen`. See ["Changes in 2.0.0"](#changes-in-200)  |
-| [**1.2.2**](https://github.com/elm-explorations/test/tree/1.2.2)                     | Fixes a crash in `Test.Html` when the HTML contains nested `Html.Lazy` nodes. [#78](https://github.com/elm-explorations/test/issues/78)            |
-| [**1.2.1**](https://github.com/elm-explorations/test/tree/1.2.1)                     | Many small documentation fixes.  Improve error messages when failing to simulate an event.                                                         |
-| [**1.2.0**](https://github.com/elm-explorations/test/tree/1.2.0)                     | Add HTML tests. [#41](https://github.com/elm-explorations/test/pull/41)                                                                            |
-| [**1.0.0**](https://github.com/elm-explorations/test/tree/1.0.0)                     | Update for Elm 0.19. Remove `Fuzz.andThen`, `Fuzz.conditional`, and `Test.Runner.getFailure`. Fail on equating floats to encourage checks with tolerance. `Test.Runner.fuzz` now returns a `Result`. |
+| Version                                                          | Notes                                                                                                                                              |
+| ---------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| [**2.2.1**](https://github.com/elm-explorations/test/tree/2.2.1) | `Test.Html.Query`: Support classes set using the `class` attribute |
+| [**2.2.0**](https://github.com/elm-explorations/test/tree/2.2.0) | `Fuzz`: Add `Fuzz.filterMap`                                       |
+| [**2.1.2**](https://github.com/elm-explorations/test/tree/2.1.2) | `Fuzz`: Remove arbitrary limit on amount of randomness drawn       |
+| [**2.1.1**](https://github.com/elm-explorations/test/tree/2.1.1) | `Test.Html.Query`: Change how boolean attributes are rendered      |
+| [**2.1.0**](https://github.com/elm-explorations/test/tree/2.1.0) | Add `Test.Html.Selector.exactText`                                 |
+| [**2.0.1**](https://github.com/elm-explorations/test/tree/2.0.1) | Documentation fixes                                                |
+| [**2.0.0**](https://github.com/elm-explorations/test/tree/2.0.0) | Reimplements fuzzing+shrinking, adds fuzzer distribution reporting. Most notably readds `Fuzz.andThen`. See ["Changes in 2.0.0"](#changes-in-200)  |
+| [**1.2.2**](https://github.com/elm-explorations/test/tree/1.2.2) | Fixes a crash in `Test.Html` when the HTML contains nested `Html.Lazy` nodes. [#78](https://github.com/elm-explorations/test/issues/78)            |
+| [**1.2.1**](https://github.com/elm-explorations/test/tree/1.2.1) | Many small documentation fixes.  Improve error messages when failing to simulate an event.                                                         |
+| [**1.2.0**](https://github.com/elm-explorations/test/tree/1.2.0) | Add HTML tests. [#41](https://github.com/elm-explorations/test/pull/41)                                                                            |
+| [**1.0.0**](https://github.com/elm-explorations/test/tree/1.0.0) | Update for Elm 0.19. Remove `Fuzz.andThen`, `Fuzz.conditional`, and `Test.Runner.getFailure`. Fail on equating floats to encourage checks with tolerance. `Test.Runner.fuzz` now returns a `Result`. |
 | renamed from **elm-community/elm-test** (below) to **elm-explorations/test** (above) |                                                                                                                                                    |
-| [**4.0.0**](https://github.com/elm-community/elm-test/tree/4.0.0)                    | Add `only`, `skip`, `todo`; change `Fuzz.frequency` to fail rather than crash on bad input, disallow tests with blank or duplicate descriptions.   |
-| [**3.1.0**](https://github.com/elm-community/elm-test/tree/3.1.0)                    | Add `Expect.all`                                                                                                                                   |
-| [**3.0.0**](https://github.com/elm-community/elm-test/tree/3.0.0)                    | Update for Elm 0.18; switch the argument order of `Fuzz.andMap`.                                                                                   |
-| [**2.1.0**](https://github.com/elm-community/elm-test/tree/2.1.0)                    | Switch to rose trees for `Fuzz.andThen`, other API additions.                                                                                      |
-| [**2.0.0**](https://github.com/elm-community/elm-test/tree/2.0.0)                    | Scratch-rewrite to project-fuzzball                                                                                                                |
-| [**1.0.0**](https://github.com/elm-community/elm-test/tree/1.0.0)                    | ElmTest initial release                                                                                                                            |
+| [**4.0.0**](https://github.com/elm-community/elm-test/tree/4.0.0) | Add `only`, `skip`, `todo`; change `Fuzz.frequency` to fail rather than crash on bad input, disallow tests with blank or duplicate descriptions. |
+| [**3.1.0**](https://github.com/elm-community/elm-test/tree/3.1.0) | Add `Expect.all`                                                 |
+| [**3.0.0**](https://github.com/elm-community/elm-test/tree/3.0.0) | Update for Elm 0.18; switch the argument order of `Fuzz.andMap`. |
+| [**2.1.0**](https://github.com/elm-community/elm-test/tree/2.1.0) | Switch to rose trees for `Fuzz.andThen`, other API additions.    |
+| [**2.0.0**](https://github.com/elm-community/elm-test/tree/2.0.0) | Scratch-rewrite to project-fuzzball                              |
+| [**1.0.0**](https://github.com/elm-community/elm-test/tree/1.0.0) | ElmTest initial release                                          |
 
 ## Changes in 2.0.0
 

elm.json

@@ -3,7 +3,7 @@
     "name": "elm-explorations/test",
     "summary": "Write unit and fuzz tests for Elm code.",
     "license": "BSD-3-Clause",
-    "version": "2.2.0",
+    "version": "2.2.1",
     "exposed-modules": [
         "Test",
         "Test.Runner",

src/MicroListExtra.elm

@@ -6,6 +6,7 @@ module MicroListExtra exposing
     , setAt
     , splitWhen
     , transpose
+    , unique
     )
 
 
@@ -98,3 +99,26 @@ rowsLength listOfLists =
 
         x :: _ ->
             List.length x
+
+
+unique : List a -> List a
+unique list =
+    uniqueHelp identity [] list []
+
+
+uniqueHelp : (a -> b) -> List b -> List a -> List a -> List a
+uniqueHelp f existing remaining accumulator =
+    case remaining of
+        [] ->
+            List.reverse accumulator
+
+        first :: rest ->
+            let
+                computedFirst =
+                    f first
+            in
+            if List.member computedFirst existing then
+                uniqueHelp f existing rest accumulator
+
+            else
+                uniqueHelp f (computedFirst :: existing) rest (first :: accumulator)

src/Test/Html/Internal/ElmHtml/InternalTypes.elm

@@ -2,6 +2,7 @@ module Test.Html.Internal.ElmHtml.InternalTypes exposing
     ( ElmHtml(..), TextTagRecord, NodeRecord, CustomNodeRecord, MarkdownNodeRecord
     , Facts, Tagger, EventHandler, ElementKind(..)
     , Attribute(..), AttributeRecord, NamespacedAttributeRecord, PropertyRecord, EventRecord
+    , Validation(..), validationMessage, validationFromMessage
     , decodeElmHtml, emptyFacts, toElementKind, decodeAttribute
     )
 
@@ -13,6 +14,8 @@ module Test.Html.Internal.ElmHtml.InternalTypes exposing
 
 @docs Attribute, AttributeRecord, NamespacedAttributeRecord, PropertyRecord, EventRecord
 
+@docs Validation, validationMessage, validationFromMessage
+
 @docs decodeElmHtml, emptyFacts, toElementKind, decodeAttribute
 
 -}
@@ -317,16 +320,56 @@ decodeStyles =
         ]
 
 
+type Validation
+    = ClassVsClassNameValidation
+
+
+classVsClassNameValidationMessage : String
+classVsClassNameValidationMessage =
+    "Found the `class` attribute and the `className` property used in the same HTML node. This would result in unspecified behaviour, and elm-test wouldn't be able to reliably query for classnames. Please only use one of the two."
+
+
+validationMessage : Validation -> String
+validationMessage validation =
+    case validation of
+        ClassVsClassNameValidation ->
+            classVsClassNameValidationMessage
+
+
+validationFromMessage : String -> Maybe Validation
+validationFromMessage message =
+    if message == classVsClassNameValidationMessage then
+        Just ClassVsClassNameValidation
+
+    else
+        Nothing
+
+
 {-| grab things from attributes via a decoder, then anything that isn't filtered on
 the object
 -}
-decodeOthers : Json.Decode.Decoder a -> Json.Decode.Decoder (Dict String a)
-decodeOthers otherDecoder =
+decodeOthers : Json.Decode.Decoder a -> Maybe Validation -> Json.Decode.Decoder (Dict String a)
+decodeOthers otherDecoder validation =
     decodeAttributes otherDecoder
         |> Json.Decode.andThen
             (\attributes ->
                 decodeDictFilterMap otherDecoder
                     |> Json.Decode.map (filterKnownKeys >> Dict.union attributes)
+                    |> (case validation of
+                            Nothing ->
+                                identity
+
+                            Just ClassVsClassNameValidation ->
+                                Json.Decode.andThen
+                                    (\dict ->
+                                        if Dict.member "class" dict && Dict.member "className" dict then
+                                            -- Due to Json.Decode.Error API we need to drop down to strings.
+                                            Json.Decode.fail classVsClassNameValidationMessage
+
+                                        else
+                                            Json.Decode.succeed dict
+                                    )
+                       )
             )
 
 
@@ -374,8 +417,8 @@ decodeFacts (HtmlContext taggers eventDecoder) =
         decodeStyles
         (decodeEvents (eventDecoder taggers))
         (Json.Decode.maybe (Json.Decode.field attributeNamespaceKey Json.Decode.value))
-        (decodeOthers Json.Decode.string)
-        (decodeOthers Json.Decode.bool)
+        (decodeOthers Json.Decode.string (Just ClassVsClassNameValidation))
+        (decodeOthers Json.Decode.bool Nothing)
 
 
 {-| Just empty facts

src/Test/Html/Internal/ElmHtml/Query.elm

@@ -262,8 +262,33 @@ hasStyle style facts =
 
 classnames : Facts msg -> List String
 classnames facts =
-    Dict.get "className" facts.stringAttributes
-        |> Maybe.withDefault ""
+    (case
+        ( Dict.get "class" facts.stringAttributes
+        , Dict.get "className" facts.stringAttributes
+        )
+     of
+        ( Just _, Just _ ) ->
+            -- If you use both the `class` attribute and the `className` property at the same time,
+            -- it’s undefined which classes you end up with. It depends on which order they are specified,
+            -- which order elm/virtual-dom happens to apply them, and which of them changed most recently.
+            -- Mixing both is not a good idea.
+            --
+            -- This code should be impossible to reach because of the validation in
+            -- Test.Html.Internal.ElmHtml.InternalTypes.decodeOthers.
+            --
+            -- If we ever reach this code, silently claim that there are no classes (that no classes match
+            -- the node).
+            ""
+
+        ( Just class, Nothing ) ->
+            class
+
+        ( Nothing, Just className ) ->
+            className
+
+        ( Nothing, Nothing ) ->
+            ""
+    )
         |> String.split " "
 
 

src/Test/Html/Internal/Inert.elm

@@ -1,14 +1,15 @@
-module Test.Html.Internal.Inert exposing (Node, fromElmHtml, fromHtml, parseAttribute, toElmHtml)
+module Test.Html.Internal.Inert exposing (Node, Error(..), fromElmHtml, fromHtml, parseAttribute, toElmHtml)
 
 {-| Inert Html - that is, can't do anything with events.
 
-@docs Node, fromElmHtml, fromHtml, parseAttribute, toElmHtml
+@docs Node, Error, fromElmHtml, fromHtml, parseAttribute, toElmHtml
 
 -}
 
 import Elm.Kernel.HtmlAsJson
 import Html exposing (Html)
 import Json.Decode
+import MicroListExtra as List
 import Test.Html.Internal.ElmHtml.InternalTypes as InternalTypes exposing (ElmHtml, EventHandler, Tagger, decodeAttribute, decodeElmHtml)
 import VirtualDom
 
@@ -17,14 +18,45 @@ type Node msg
     = Node (ElmHtml msg)
 
 
-fromHtml : Html msg -> Result String (Node msg)
+type Error
+    = DecodeError Json.Decode.Error
+    | ValidationErrors { deduped : List InternalTypes.Validation }
+
+
+fromHtml : Html msg -> Result Error (Node msg)
 fromHtml html =
     case Json.Decode.decodeValue (decodeElmHtml taggedEventDecoder) (toJson html) of
         Ok elmHtml ->
             Ok (Node elmHtml)
 
         Err jsonError ->
-            Err (Json.Decode.errorToString jsonError)
+            case findValidationErrors jsonError of
+                [] ->
+                    Err (DecodeError jsonError)
+
+                failedValidations ->
+                    Err (ValidationErrors { deduped = List.unique failedValidations })
+
+
+findValidationErrors : Json.Decode.Error -> List InternalTypes.Validation
+findValidationErrors error =
+    case error of
+        Json.Decode.Field _ e ->
+            findValidationErrors e
+
+        Json.Decode.Index _ e ->
+            findValidationErrors e
+
+        Json.Decode.OneOf es ->
+            List.concatMap findValidationErrors es
+
+        Json.Decode.Failure stringError _ ->
+            case InternalTypes.validationFromMessage stringError of
+                Nothing ->
+                    []
+
+                Just validation ->
+                    [ validation ]
 
 
 fromElmHtml : ElmHtml msg -> Node msg

src/Test/Html/Query.elm

@@ -27,6 +27,8 @@ module Test.Html.Query exposing
 
 import Expect exposing (Expectation)
 import Html exposing (Html)
+import Json.Decode
+import Test.Html.Internal.ElmHtml.InternalTypes as InternalTypes
 import Test.Html.Internal.Inert as Inert
 import Test.Html.Query.Internal as Internal exposing (failWithQuery)
 import Test.Html.Selector exposing (Selector)
@@ -95,8 +97,11 @@ fromHtml html =
             Ok node ->
                 Internal.Query node []
 
-            Err message ->
-                Internal.InternalError message
+            Err (Inert.DecodeError decodeError) ->
+                Internal.InternalError (Json.Decode.errorToString decodeError)
+
+            Err (Inert.ValidationErrors validations) ->
+                Internal.ValidationErrors validations
 
 
 
@@ -377,12 +382,23 @@ contains expectedHtml (Internal.Single showTrace query) =
                 |> failWithQuery showTrace "Query.contains" query
 
         Err errors ->
-            Expect.fail <|
-                String.join "\n" <|
-                    List.concat
-                        [ [ "Internal Error: failed to decode the virtual dom.  Please report this at <https://github.com/elm-explorations/test/issues>." ]
-                        , errors
-                        ]
+            errors
+                |> List.map
+                    (\error ->
+                        (case error of
+                            Inert.DecodeError decodeError ->
+                                [ "Internal Error: failed to decode the virtual dom.  Please report this at <https://github.com/elm-explorations/test/issues>."
+                                , Json.Decode.errorToString decodeError
+                                ]
+
+                            Inert.ValidationErrors { deduped } ->
+                                deduped
+                                    |> List.map InternalTypes.validationMessage
+                        )
+                            |> String.join "\n"
+                    )
+                |> String.join "\n\n"
+                |> Expect.fail
 
 
 collectResults : List (Result x a) -> Result (List x) (List a)