Effect handler errors

modules/circe/src/test/scala/CirceEffectHandlerErrorData.scala

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+// Copyright (c) 2016-2023 Association of Universities for Research in Astronomy, Inc. (AURA)
+// Copyright (c) 2016-2023 Grackle Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import cats.effect.Sync
+import cats.implicits._
+import fs2.concurrent.SignallingRef
+
+import grackle.Cursor
+import grackle.Query
+import grackle.Query.EffectHandler
+import grackle.Result
+import grackle.circe.CirceMapping
+import grackle.syntax._
+
+class TestCirceEffectHandlerErrorMapping[F[_]: Sync](ref: SignallingRef[F, Int]) extends CirceMapping[F] {
+  val schema =
+    schema"""
+      type Query {
+        n: Int!
+        s: String!
+      }
+    """
+
+  val QueryType = schema.ref("Query")
+
+  case class TestEffectHandler[A](value: A) extends EffectHandler[F] {
+    def runEffects(queries: List[(Query, Cursor)]): F[Result[List[Cursor]]] =
+      queries.traverse { case (_, _) =>
+        ref.update(_ + 1).as(
+          Result.failure[Cursor](s"value: $value")
+        )
+      }.map(_.sequence)
+  }
+
+  val nHandler = TestEffectHandler(42)
+  val sHandler = TestEffectHandler("hi")
+
+  val typeMappings = List(
+    ObjectMapping(
+      tpe = QueryType,
+      fieldMappings =
+        List(
+          EffectField("n", nHandler, Nil),
+          EffectField("s", sHandler, Nil)
+        )
+    )
+  )
+
+
+}

modules/circe/src/test/scala/CirceEffectHandlerErrorSuite.scala

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+// Copyright (c) 2016-2023 Association of Universities for Research in Astronomy, Inc. (AURA)
+// Copyright (c) 2016-2023 Grackle Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import cats.effect.IO
+import fs2.concurrent.SignallingRef
+import io.circe.Json
+import io.circe.literal._
+import munit.CatsEffectSuite
+
+final class CirceEffectHandlerErrorSuite extends CatsEffectSuite {
+  test("circe effect handler") {
+    val query = """
+      query {
+        s,
+        n
+      }
+    """
+
+    val expected = json"""
+      {
+        "errors" : [
+          { "message": "value: hi" },
+          { "message": "value: 42" }
+        ]
+      }
+    """
+
+    val prg: IO[(Json, Int)] =
+      for {
+        ref  <- SignallingRef[IO, Int](0)
+        map  =  new TestCirceEffectHandlerErrorMapping(ref)
+        res  <- map.compileAndRun(query)
+        eff  <- ref.get
+      } yield (res, eff)
+
+    assertIO(prg, (expected, 2))
+  }
+
+}