HTTP GET support for Akka and http4s

akka-http/src/main/scala/caliban/AkkaHttpAdapter.scala

@@ -1,39 +1,63 @@
 package caliban
 
 import akka.http.scaladsl.model.MediaTypes.`application/json`
-import akka.http.scaladsl.model.{ HttpEntity, HttpResponse }
-import akka.http.scaladsl.server.Route
+import akka.http.scaladsl.model.{ HttpEntity, HttpResponse, StatusCodes }
+import akka.http.scaladsl.server.Directives.complete
+import akka.http.scaladsl.server.{ Route, StandardRoute }
 import caliban.Value.NullValue
 import de.heikoseeberger.akkahttpcirce.FailFastCirceSupport
+import io.circe.Decoder.Result
+import io.circe.Json
 import io.circe.syntax._
 import zio.{ Runtime, URIO }
 
 import scala.concurrent.ExecutionContext
 
 object AkkaHttpAdapter extends FailFastCirceSupport {
 
-  private def execute[R, E](
+  private def executeHttpResponse[R, E](
     interpreter: GraphQLInterpreter[R, E],
-    query: GraphQLRequest
-  ): URIO[R, GraphQLResponse[E]] =
-    interpreter.execute(query.query, query.operationName, query.variables.getOrElse(Map()))
+    request: GraphQLRequest
+  ): URIO[R, HttpResponse] =
+    interpreter
+      .execute(request.query, request.operationName, request.variables.getOrElse(Map()))
+      .foldCause(cause => GraphQLResponse(NullValue, cause.defects).asJson, _.asJson)
+      .map(gqlResult => HttpResponse(StatusCodes.OK, entity = HttpEntity(`application/json`, gqlResult.toString())))
+
+  def getGraphQLRequest(query: String, op: Option[String], vars: Option[String]): Result[GraphQLRequest] = {
+    import io.circe.parser._
+    val variablesJs = vars.flatMap(parse(_).toOption)
+    val fields = List("query" -> Json.fromString(query)) ++
+      op.map(o => "operationName"       -> Json.fromString(o)) ++
+      variablesJs.map(js => "variables" -> js)
+    Json
+      .fromFields(fields)
+      .as[GraphQLRequest]
+  }
+
+  def completeRequest[R, E](
+    interpreter: GraphQLInterpreter[R, E]
+  )(request: GraphQLRequest)(implicit ec: ExecutionContext, runtime: Runtime[R]): StandardRoute =
+    complete(
+      runtime
+        .unsafeRunToFuture(executeHttpResponse(interpreter, request))
+        .future
+    )
 
   def makeHttpService[R, E](
     interpreter: GraphQLInterpreter[R, E]
   )(implicit ec: ExecutionContext, runtime: Runtime[R]): Route = {
     import akka.http.scaladsl.server.Directives._
-    post {
-      entity(as[GraphQLRequest]) { request =>
-        complete({
-          runtime
-            .unsafeRunToFuture(
-              execute(interpreter, request)
-                .foldCause(cause => GraphQLResponse(NullValue, cause.defects).asJson, _.asJson)
-                .map(gqlResult => HttpResponse(200, entity = HttpEntity(`application/json`, gqlResult.toString())))
-            )
-            .future
-        })
+
+    get {
+      parameters((Symbol("query").as[String], Symbol("operationName").?, Symbol("variables").?)) {
+        case (query, op, vars) =>
+          getGraphQLRequest(query, op, vars)
+            .fold(failWith, completeRequest(interpreter))
+      }
+    } ~
+      post {
+        entity(as[GraphQLRequest]) { completeRequest(interpreter) }
       }
-    }
   }
 }

build.sbt

@@ -1,9 +1,9 @@
 import sbtcrossproject.CrossPlugin.autoImport.{ crossProject, CrossType }
 
-val mainScala     = "2.12.10"
-val allScala      = Seq("2.13.1", mainScala)
-val http4sVersion = "0.21.0-M5"
-
+val mainScala       = "2.12.10"
+val allScala        = Seq("2.13.1", mainScala)
+val http4sVersion   = "0.21.0-M5"
+val silencerVersion = "1.4.4"
 inThisBuild(
   List(
     organization := "com.github.ghostdogpr",
@@ -108,7 +108,9 @@ lazy val http4s = project
       compilerPlugin(
         ("org.typelevel" %% "kind-projector" % "0.11.0")
           .cross(CrossVersion.full)
-      )
+      ),
+      compilerPlugin("com.github.ghik" % "silencer-plugin" % silencerVersion cross CrossVersion.full),
+      "com.github.ghik" % "silencer-lib" % silencerVersion % Provided cross CrossVersion.full
     )
   )
   .dependsOn(coreJVM)

http4s/src/main/scala/caliban/Http4sAdapter.scala

@@ -7,7 +7,8 @@ import cats.effect.Effect
 import cats.effect.syntax.all._
 import cats.~>
 import fs2.{ Pipe, Stream }
-import io.circe._
+import io.circe.Decoder.Result
+import io.circe.Json
 import io.circe.parser._
 import io.circe.syntax._
 import org.http4s._
@@ -18,6 +19,7 @@ import org.http4s.websocket.WebSocketFrame
 import org.http4s.websocket.WebSocketFrame.Text
 import zio._
 import zio.interop.catz._
+import com.github.ghik.silencer.silent
 
 object Http4sAdapter {
 
@@ -32,7 +34,24 @@ object Http4sAdapter {
   def makeRestService[R, E](interpreter: GraphQLInterpreter[R, E]): HttpRoutes[RIO[R, *]] =
     makeHttpService(interpreter)
 
-  def makeHttpService[R, E](interpreter: GraphQLInterpreter[R, E]): HttpRoutes[RIO[R, *]] = {
+  private def getGraphQLRequest(query: String, op: Option[String], vars: Option[String]): Result[GraphQLRequest] = {
+    val variablesJs = vars.flatMap(parse(_).toOption)
+    val fields = List("query" -> Json.fromString(query)) ++
+      op.map(o => "operationName"       -> Json.fromString(o)) ++
+      variablesJs.map(js => "variables" -> js)
+    Json
+      .fromFields(fields)
+      .as[GraphQLRequest]
+  }
+
+  private def getGraphQLRequest(params: Map[String, String]): Result[GraphQLRequest] =
+    getGraphQLRequest(
+      params.getOrElse("query", ""),
+      params.get("operationName"),
+      params.get("variables")
+    )
+
+  @silent def makeHttpService[R, E](interpreter: GraphQLInterpreter[R, E]): HttpRoutes[RIO[R, *]] = {
     object dsl extends Http4sDsl[RIO[R, *]]
     import dsl._
 
@@ -43,6 +62,12 @@ object Http4sAdapter {
           result   <- executeToJson(interpreter, query)
           response <- Ok(result)
         } yield response
+      case req @ GET -> Root =>
+        for {
+          query    <- Task.fromEither(getGraphQLRequest(req.params))
+          result   <- executeToJson(interpreter, query)
+          response <- Ok(result)
+        } yield response
     }
   }