feat(compiler): Generate empty calls to responseHandlerSrv [LNG-286] (#979)

* Add noEmptyResponse

* Fix tests

api/api-npm/index.d.ts

@@ -37,6 +37,8 @@ type CommonArgs = {
   targetType?: "ts" | "js" | "air" | undefined;
   /** Compile aqua in tracing mode (for debugging purposes). Default: false */
   tracing?: boolean | undefined;
+  /** Do not generate response call if there are no returned values */
+  noEmptyResponse?: boolean | undefined;
 };
 
 type CodeString = {

api/api-npm/index.js

@@ -7,6 +7,7 @@ function getConfig({
   noXor = false,
   targetType = "air",
   tracing = false,
+  noEmptyResponse = false,
 }) {
   return new AquaConfig(
     logLevel,
@@ -19,6 +20,7 @@ function getConfig({
       air: "air",
     }[targetType],
     tracing,
+    noEmptyResponse,
   );
 }
 

api/api/.js/src/main/scala/api/types/InputTypes.scala

@@ -4,9 +4,9 @@ import aqua.api.AquaAPIConfig
 import aqua.api.TargetType.*
 import aqua.js.{FunctionDefJs, ServiceDefJs}
 import aqua.model.transform.TransformConfig
+
 import cats.data.Validated.{invalidNec, validNec}
 import cats.data.{Chain, NonEmptyChain, Validated, ValidatedNec}
-
 import scala.scalajs.js
 import scala.scalajs.js.JSConverters.*
 import scala.scalajs.js.annotation.{JSExport, JSExportTopLevel}
@@ -47,7 +47,9 @@ class AquaConfig(
   @JSExport
   val targetType: js.UndefOr[String],
   @JSExport
-  val tracing: js.UndefOr[Boolean]
+  val tracing: js.UndefOr[Boolean],
+  @JSExport
+  val noEmptyResponse: js.UndefOr[Boolean]
 )
 
 object AquaConfig {
@@ -69,7 +71,8 @@ object AquaConfig {
           constants = cjs.constants.map(_.toList).getOrElse(Nil),
           noXor = cjs.noXor.getOrElse(false),
           noRelay = cjs.noRelay.getOrElse(false),
-          tracing = cjs.tracing.getOrElse(false)
+          tracing = cjs.tracing.getOrElse(false),
+          noEmptyResponse = cjs.noEmptyResponse.getOrElse(false)
         )
       }
   }

api/api/src/main/scala/aqua/api/AquaAPIConfig.scala

@@ -10,12 +10,14 @@ case class AquaAPIConfig(
   constants: List[String] = Nil,
   noXor: Boolean = false, // TODO: Remove
   noRelay: Boolean = false,
-  tracing: Boolean = false
+  tracing: Boolean = false,
+  noEmptyResponse: Boolean = false
 ) {
 
   def getTransformConfig: TransformConfig = {
     val config = TransformConfig(
-      tracing = Option.when(tracing)(TransformConfig.TracingConfig.default)
+      tracing = Option.when(tracing)(TransformConfig.TracingConfig.default),
+      noEmptyResponse = noEmptyResponse
     )
 
     if (noRelay) config.copy(relayVarName = None)

compiler/src/test/scala/aqua/compiler/AquaCompilerSpec.scala

@@ -1,12 +1,15 @@
 package aqua.compiler
 
-import aqua.model.{CallModel, ForModel, FunctorModel, LiteralModel, ValueModel, VarModel}
+import aqua.model.AquaContext
+import aqua.model.CallServiceModel
+import aqua.model.FlattenModel
 import aqua.model.transform.ModelBuilder
-import aqua.model.transform.TransformConfig
 import aqua.model.transform.Transform
-import aqua.parser.ParserError
+import aqua.model.transform.TransformConfig
+import aqua.model.{CallModel, ForModel, FunctorModel, LiteralModel, ValueModel, VarModel}
 import aqua.parser.Ast
 import aqua.parser.Parser
+import aqua.parser.ParserError
 import aqua.parser.lift.Span
 import aqua.parser.lift.Span.S
 import aqua.raw.ConstantRaw
@@ -18,15 +21,12 @@ import aqua.types.{ArrayType, CanonStreamType, LiteralType, ScalarType, StreamTy
 import cats.Id
 import cats.data.{Chain, NonEmptyChain, NonEmptyMap, Validated, ValidatedNec}
 import cats.instances.string.*
-import cats.syntax.show.*
-import cats.syntax.option.*
 import cats.syntax.either.*
+import cats.syntax.option.*
+import cats.syntax.show.*
+import org.scalatest.Inside
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
-import org.scalatest.Inside
-import aqua.model.AquaContext
-import aqua.model.FlattenModel
-import aqua.model.CallServiceModel
 
 class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
   import ModelBuilder.*
@@ -358,7 +358,8 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
             join(VarModel(streamName, streamType), arg),
             decrement
           )
-        )
+        ),
+        emptyRespCall(transformCfg, initPeer)
       ),
       errorCall(transformCfg, 0, initPeer)
     )

model/transform/src/main/scala/aqua/model/transform/Transform.scala

@@ -1,25 +1,25 @@
 package aqua.model.transform
 
+import aqua.model.*
 import aqua.model.inline.ArrowInliner
 import aqua.model.inline.state.InliningState
+import aqua.model.transform.TransformConfig.TracingConfig
 import aqua.model.transform.funcop.*
 import aqua.model.transform.pre.*
+import aqua.model.transform.pre.{CallbackErrorHandler, ErrorHandler}
 import aqua.model.transform.topology.Topology
-import aqua.model.*
 import aqua.raw.ops.RawTag
 import aqua.raw.value.VarRaw
 import aqua.res.*
 import aqua.types.ScalarType
-import aqua.model.transform.TransformConfig.TracingConfig
-import aqua.model.transform.pre.{CallbackErrorHandler, ErrorHandler}
 
 import cats.Eval
 import cats.data.Chain
 import cats.free.Cofree
+import cats.instances.list.*
 import cats.syntax.option.*
 import cats.syntax.show.*
 import cats.syntax.traverse.*
-import cats.instances.list.*
 import scribe.Logging
 
 // API for transforming RawTag to Res
@@ -90,7 +90,8 @@ object Transform extends Logging {
 
     val resultsHandler: ResultsHandler = CallbackResultsHandler(
       callbackSrvId = conf.callbackSrvId,
-      funcName = conf.respFuncName
+      funcName = conf.respFuncName,
+      noEmptyResponse = conf.noEmptyResponse
     )
 
     val errorHandler: ErrorHandler = CallbackErrorHandler(

model/transform/src/main/scala/aqua/model/transform/TransformConfig.scala

@@ -1,19 +1,33 @@
 package aqua.model.transform
 
 import aqua.model.{AquaContext, LiteralModel, ValueModel, VarModel}
-import aqua.raw.{ConstantRaw, RawContext, RawPart}
 import aqua.raw.value.{LiteralRaw, ValueRaw, VarRaw}
+import aqua.raw.{ConstantRaw, RawContext, RawPart}
 import aqua.types.ScalarType
+
 import cats.data.Chain
 import cats.kernel.Monoid
 
-// TODO docs
+/**
+ * Configuration for function pre transformer
+ *
+ * @param getDataService - name of the service that provides arguments
+ * @param callbackService - name of the service that provides callbacks
+ * @param errorHandlingService - name of the service that handles errors
+ * @param errorFuncName - name of the function that handles errors (in errorHandlingService)
+ * @param respFuncName - name of the function that handles responses (in getDataService)
+ * @param noEmptyResponse - if true, do not generate response call if there is no return values
+ * @param relayVarName - name of the relay variable
+ * @param tracing - tracing configuration
+ * @param constants - list of constants
+ */
 case class TransformConfig(
   getDataService: String = "getDataSrv",
   callbackService: String = "callbackSrv",
   errorHandlingService: String = "errorHandlingSrv",
   errorFuncName: String = "error",
   respFuncName: String = "response",
+  noEmptyResponse: Boolean = false,
   relayVarName: Option[String] = Some("-relay-"),
   tracing: Option[TransformConfig.TracingConfig] = None,
   constants: List[ConstantRaw] = Nil

model/transform/src/main/scala/aqua/model/transform/pre/ResultsHandler.scala

@@ -1,8 +1,8 @@
 package aqua.model.transform.pre
 
-import aqua.types.Type
 import aqua.raw.ops.{Call, CallArrowRawTag, RawTag}
 import aqua.raw.value.{ValueRaw, VarRaw}
+import aqua.types.Type
 
 import cats.syntax.option.*
 
@@ -10,11 +10,14 @@ trait ResultsHandler {
   def handleResults(results: List[(String, Type)]): Option[RawTag.Tree]
 }
 
-case class CallbackResultsHandler(callbackSrvId: ValueRaw, funcName: String)
+case class CallbackResultsHandler(
-    extends ResultsHandler {
+  callbackSrvId: ValueRaw,
+  funcName: String,
+  noEmptyResponse: Boolean
+) extends ResultsHandler {
 
   override def handleResults(results: List[(String, Type)]): Option[RawTag.Tree] =
-    if (results.isEmpty) none
+    if (results.isEmpty && noEmptyResponse) none
     else {
       val resultVars = results.map(VarRaw.apply.tupled)
       val call = Call(

model/transform/src/test/scala/aqua/model/transform/ModelBuilder.scala

@@ -1,22 +1,22 @@
 package aqua.model.transform
 
 import aqua.model.*
+import aqua.model.FailModel
+import aqua.model.IntoIndexModel
+import aqua.model.OnModel
+import aqua.model.inline.raw.StreamGateInliner
 import aqua.raw.ops.Call
 import aqua.raw.value.{LiteralRaw, ValueRaw, VarRaw}
-import aqua.{model, res}
-import aqua.res.{CallRes, CallServiceRes, MakeRes}
-import aqua.types.{ArrayType, LiteralType, ScalarType}
-import aqua.types.StreamType
-import aqua.model.IntoIndexModel
-import aqua.model.inline.raw.StreamGateInliner
-import aqua.model.OnModel
-import aqua.model.FailModel
 import aqua.res.ResolvedOp
+import aqua.res.{CallRes, CallServiceRes, MakeRes}
+import aqua.types.StreamType
+import aqua.types.{ArrayType, LiteralType, ScalarType}
+import aqua.{model, res}
 
-import scala.language.implicitConversions
 import cats.data.Chain
 import cats.data.Chain.==:
 import cats.syntax.option.*
+import scala.language.implicitConversions
 
 object ModelBuilder {
   implicit def rawToValue(raw: ValueRaw): ValueModel = ValueModel.fromRaw(raw)
@@ -88,15 +88,24 @@ object ModelBuilder {
       )
       .leaf
 
-  def respCall(bc: TransformConfig, value: ValueModel, on: ValueModel = initPeer) =
+  def respCallImpl(
-    res
+    config: TransformConfig,
-      .CallServiceRes(
+    arguments: List[ValueModel],
-        ValueModel.fromRaw(bc.callbackSrvId),
+    on: ValueModel = initPeer
-        bc.respFuncName,
+  ) = res
-        CallRes(value :: Nil, None),
+    .CallServiceRes(
-        on
+      ValueModel.fromRaw(config.callbackSrvId),
-      )
+      config.respFuncName,
-      .leaf
+      CallRes(arguments, None),
+      on
+    )
+    .leaf
+
+  def respCall(config: TransformConfig, value: ValueModel, on: ValueModel = initPeer) =
+    respCallImpl(config, value :: Nil, on)
+
+  def emptyRespCall(config: TransformConfig, on: ValueModel = initPeer) =
+    respCallImpl(config, Nil)
 
   def dataCall(bc: TransformConfig, name: String, on: ValueModel = initPeer) =
     res

model/transform/src/test/scala/aqua/model/transform/TransformSpec.scala

@@ -4,15 +4,15 @@ import aqua.model.transform.ModelBuilder
 import aqua.model.transform.{Transform, TransformConfig}
 import aqua.model.{CallModel, FuncArrow, LiteralModel, VarModel}
 import aqua.raw.ops.{Call, CallArrowRawTag, FuncOp, OnTag, RawTag, SeqTag}
-import aqua.raw.value.{LiteralRaw, VarRaw}
-import aqua.types.{ArrowType, NilType, ProductType, ScalarType}
 import aqua.raw.value.{LiteralRaw, ValueRaw, VarRaw}
+import aqua.raw.value.{LiteralRaw, VarRaw}
 import aqua.res.{CallRes, CallServiceRes, MakeRes, SeqRes, XorRes}
+import aqua.types.{ArrowType, NilType, ProductType, ScalarType}
 
-import org.scalatest.flatspec.AnyFlatSpec
-import org.scalatest.matchers.should.Matchers
 import cats.data.Chain
 import cats.syntax.show.*
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
 class TransformSpec extends AnyFlatSpec with Matchers {