Experiment with an expectGraphQL

Author: vodik

src/GraphQL/Client/Http.elm

@@ -8,7 +8,9 @@ module GraphQL.Client.Http exposing (Error(..), RequestError, DocumentLocation,
 
 import GraphQL.Client.Http.Util as Util
 import GraphQL.Request.Builder as Builder
+import GraphQL.Response as Response
 import Http
+import Json.Decode
 import Task exposing (Task)
 
 
@@ -75,9 +77,7 @@ send :
 send options request toMsg =
     let
         expect =
-            Http.expectJson
-                (Result.mapError (Util.convertHttpError HttpError GraphQLError) >> toMsg)
-                (Util.dataDecoder (Builder.responseDataDecoder request))
+            expectGraphQL toMsg request
 
         documentString =
             Builder.requestBody request
@@ -89,5 +89,39 @@ send options request toMsg =
         |> Http.request
 
 
+expectGraphQL :
+    (Result Error result -> msg)
+    -> Builder.Request operationType result
+    -> Http.Expect msg
+expectGraphQL toMsg request =
+    let
+        decoder =
+            Json.Decode.map2 (\errors data -> ( errors, data ))
+                (Json.Decode.maybe (Json.Decode.field "errors" Response.errorsDecoder))
+                (Json.Decode.field "data" (Builder.responseDataDecoder request))
+    in
+    Http.expectStringResponse toMsg <|
+        \response ->
+            case response of
+                Http.BadUrl_ url ->
+                    Err (HttpError (Http.BadUrl url))
+
+                Http.Timeout_ ->
+                    Err (HttpError Http.Timeout)
+
+                Http.NetworkError_ ->
+                    Err (HttpError Http.NetworkError)
+
+                Http.BadStatus_ metadata body ->
+                    Err (HttpError (Http.BadStatus metadata.statusCode))
+
+                Http.GoodStatus_ metadata body ->
+                    case Json.Decode.decodeString decoder body of
+                        Ok ( Just errors, _ ) ->
+                            Err (GraphQLError errors)
+
+                        Ok ( Nothing, data ) ->
+                            Ok data
 
--- |> Task.mapError (
+                        Err err ->
+                            Err (HttpError (Http.BadBody (Json.Decode.errorToString err)))

src/GraphQL/Client/Http/Util.elm

@@ -1,4 +1,4 @@
-module GraphQL.Client.Http.Util exposing (..)
+module GraphQL.Client.Http.Util exposing (DocumentLocation, Error(..), RequestConfig, RequestError, RequestOptions, defaultRequestOptions, parameterizedUrl, postBody, postBodyJson, requestConfig)
 
 import GraphQL.Response as Response
 import Http
@@ -18,7 +18,7 @@ postBodyJson documentString variableValues =
                 |> Maybe.map (\obj -> [ ( "variables", obj ) ])
                 |> Maybe.withDefault []
     in
-        Json.Encode.object ([ ( "query", documentValue ) ] ++ extraParams)
+    Json.Encode.object ([ ( "query", documentValue ) ] ++ extraParams)
 
 
 postBody : String -> Maybe Json.Encode.Value -> Http.Body
@@ -32,6 +32,7 @@ parameterizedUrl url documentString variableValues =
         firstParamPrefix =
             if String.contains "?" url then
                 "&"
+
             else
                 "?"
 
@@ -46,7 +47,7 @@ parameterizedUrl url documentString variableValues =
                     )
                 |> Maybe.withDefault ""
     in
-        url ++ queryParam ++ variablesParam
+    url ++ queryParam ++ variablesParam
 
 
 type alias RequestOptions =
@@ -81,7 +82,7 @@ type alias RequestConfig a =
     , body : Http.Body
     , expect : Http.Expect a
     , timeout : Maybe Float
-    , tracker: Maybe String
+    , tracker : Maybe String
     }
 
 
@@ -105,40 +106,15 @@ requestConfig requestOptions documentString expect variableValues =
         ( url, body ) =
             if requestOptions.method == "GET" then
                 ( parameterizedUrl requestOptions.url documentString variableValues, Http.emptyBody )
+
             else
                 ( requestOptions.url, postBody documentString variableValues )
     in
-        { method = requestOptions.method
-        , headers = requestOptions.headers
-        , url = url
-        , body = body
-        , expect = expect
-        , timeout = requestOptions.timeout
-        , tracker = Nothing
-        }
-
-
-dataDecoder =
-    Json.Decode.field "data"
-
-
-errorsResponseDecoder : Json.Decode.Decoder (List RequestError)
-errorsResponseDecoder =
-    Json.Decode.field "errors" Response.errorsDecoder
-
-
-convertHttpError : (Http.Error -> err) -> (List RequestError -> err) -> Http.Error -> err
-convertHttpError wrapHttpError wrapGraphQLError httpError =
-    let
-        handleErrorWithResponseBody responseBody =
-            responseBody
-                |> Json.Decode.decodeString errorsResponseDecoder
-                |> Result.map wrapGraphQLError
-                |> Result.withDefault (wrapHttpError httpError)
-    in
-        case httpError of
-            Http.BadBody body ->
-                handleErrorWithResponseBody body
-
-            _ ->
-                wrapHttpError httpError
+    { method = requestOptions.method
+    , headers = requestOptions.headers
+    , url = url
+    , body = body
+    , expect = expect
+    , timeout = requestOptions.timeout
+    , tracker = Nothing
+    }