Abstract backend (#182)

backend/air/src/main/scala/aqua/backend/air/AirBackend.scala

@@ -0,0 +1,17 @@
+package aqua.backend.air
+
+import aqua.backend.{Backend, Compiled}
+import aqua.model.AquaContext
+import aqua.model.transform.BodyConfig
+import cats.implicits.toShow
+
+object AirBackend extends Backend {
+
+  val ext = ".air"
+
+  override def generate(context: AquaContext, bc: BodyConfig): Seq[Compiled] = {
+    context.funcs.values.toList.map(fc =>
+      Compiled("." + fc.funcName + ext, FuncAirGen(fc).generateAir(bc).show)
+    )
+  }
+}

backend/air/src/main/scala/aqua/backend/air/FuncAirGen.scala

@@ -12,13 +12,4 @@ case class FuncAirGen(func: FuncCallable) {
     AirGen(
       Transform.forClient(func, conf)
     ).generate
-
-  /**
-   * Generates AIR from the optimized function body, assuming client is behind a relay
-   * @return
-   */
-  def generateClientAir(conf: BodyConfig = BodyConfig()): Air =
-    AirGen(
-      Transform.forClient(func, conf)
-    ).generate
 }

backend/js/src/main/scala/aqua/backend/js/JavaScriptBackend.scala

@@ -0,0 +1,21 @@
+package aqua.backend.js
+
+import aqua.backend.{Backend, Compiled}
+import aqua.model.AquaContext
+import aqua.model.transform.BodyConfig
+import cats.data.Chain
+
+object JavaScriptBackend extends Backend {
+
+  val ext = ".js"
+
+  override def generate(context: AquaContext, bc: BodyConfig): Seq[Compiled] = {
+    val funcs = Chain.fromSeq(context.funcs.values.toSeq).map(JavaScriptFunc(_))
+    Seq(
+      Compiled(
+        ext,
+        JavaScriptFile.Header + "\n\n" + funcs.map(_.generateTypescript(bc)).toList.mkString("\n\n")
+      )
+    )
+  }
+}

backend/js/src/main/scala/aqua/backend/js/JavaScriptFunc.scala

@@ -16,7 +16,7 @@ case class JavaScriptFunc(func: FuncCallable) {
 
   def generateTypescript(conf: BodyConfig = BodyConfig()): String = {
 
-    val tsAir = FuncAirGen(func).generateClientAir(conf)
+    val tsAir = FuncAirGen(func).generateAir(conf)
 
     val returnCallback = func.ret.as {
       s"""h.onEvent('${conf.callbackService}', '${conf.respFuncName}', (args) => {
@@ -86,8 +86,7 @@ case class JavaScriptFunc(func: FuncCallable) {
 object JavaScriptFunc {
 
   def argsToTs(at: ArrowType): String =
-    at.args
-      .zipWithIndex
+    at.args.zipWithIndex
       .map(_.swap)
       .map(kv => "arg" + kv._1)
       .mkString(", ")

backend/src/main/scala/aqua/backend/Backend.scala

@@ -0,0 +1,18 @@
+package aqua.backend
+
+import aqua.model.AquaContext
+import aqua.model.transform.BodyConfig
+
+/**
+ * Compilation result
+ * @param suffix extension or another info that will be added to a resulted file
+ * @param content a code that is used as an output
+ */
+case class Compiled(suffix: String, content: String)
+
+/**
+ * Describes how context can be finalized
+ */
+trait Backend {
+  def generate(context: AquaContext, bc: BodyConfig): Seq[Compiled]
+}

backend/ts/src/main/scala/aqua/backend/ts/TypeScriptBackend.scala

@@ -0,0 +1,21 @@
+package aqua.backend.ts
+
+import aqua.backend.{Backend, Compiled}
+import aqua.model.AquaContext
+import aqua.model.transform.BodyConfig
+import cats.data.Chain
+
+object TypeScriptBackend extends Backend {
+
+  val ext = ".ts"
+
+  override def generate(context: AquaContext, bc: BodyConfig): Seq[Compiled] = {
+    val funcs = Chain.fromSeq(context.funcs.values.toSeq).map(TypeScriptFunc(_))
+    Seq(
+      Compiled(
+        ext,
+        TypeScriptFile.Header + "\n\n" + funcs.map(_.generateTypescript(bc)).toList.mkString("\n\n")
+      )
+    )
+  }
+}

backend/ts/src/main/scala/aqua/backend/ts/TypeScriptFile.scala

@@ -4,16 +4,16 @@ import aqua.model.AquaContext
 import aqua.model.transform.BodyConfig
 import cats.data.Chain
 
-case class TypescriptFile(context: AquaContext) {
+case class TypeScriptFile(context: AquaContext) {
 
-  def funcs: Chain[TypescriptFunc] =
-    Chain.fromSeq(context.funcs.values.toSeq).map(TypescriptFunc(_))
+  def funcs: Chain[TypeScriptFunc] =
+    Chain.fromSeq(context.funcs.values.toSeq).map(TypeScriptFunc(_))
 
   def generateTS(conf: BodyConfig = BodyConfig()): String =
-    TypescriptFile.Header + "\n\n" + funcs.map(_.generateTypescript(conf)).toList.mkString("\n\n")
+    TypeScriptFile.Header + "\n\n" + funcs.map(_.generateTypescript(conf)).toList.mkString("\n\n")
 }
 
-object TypescriptFile {
+object TypeScriptFile {
 
   val Header: String =
     s"""/**

backend/ts/src/main/scala/aqua/backend/ts/TypeScriptFunc.scala

@@ -7,9 +7,9 @@ import aqua.types._
 import cats.syntax.functor._
 import cats.syntax.show._
 
-case class TypescriptFunc(func: FuncCallable) {
+case class TypeScriptFunc(func: FuncCallable) {
 
-  import TypescriptFunc._
+  import TypeScriptFunc._
 
   def argsTypescript: String =
     func.args.args.map(ad => s"${ad.name}: " + typeToTs(ad.`type`)).mkString(", ")
@@ -25,7 +25,7 @@ case class TypescriptFunc(func: FuncCallable) {
 
   def generateTypescript(conf: BodyConfig = BodyConfig()): String = {
 
-    val tsAir = FuncAirGen(func).generateClientAir(conf)
+    val tsAir = FuncAirGen(func).generateAir(conf)
 
     val returnCallback = func.ret.as {
       s"""h.onEvent('${conf.callbackService}', '${conf.respFuncName}', (args) => {
@@ -102,7 +102,7 @@ case class TypescriptFunc(func: FuncCallable) {
 
 }
 
-object TypescriptFunc {
+object TypeScriptFunc {
 
   def typeToTs(t: Type): String = t match {
     case OptionType(t) => typeToTs(t) + " | null"

build.sbt

@@ -55,7 +55,7 @@ lazy val cli = project
       "com.monovore"  %% "decline-enumeratum" % declineEnumV
     )
   )
-  .dependsOn(semantics, `backend-air`, `backend-ts`, `backend-js`, linker)
+  .dependsOn(semantics, `backend-air`, `backend-ts`, `backend-js`, linker, backend)
 
 lazy val types = project
   .settings(commons)
@@ -94,6 +94,7 @@ lazy val model = project
   .dependsOn(types)
 
 lazy val `test-kit` = project
+  .in(file("model/test-kit"))
   .settings(commons: _*)
   .dependsOn(model)
 
@@ -107,10 +108,15 @@ lazy val semantics = project
   )
   .dependsOn(model, `test-kit` % Test, parser)
 
+lazy val backend = project
+  .in(file("backend"))
+  .settings(commons: _*)
+  .dependsOn(model)
+
 lazy val `backend-air` = project
   .in(file("backend/air"))
   .settings(commons: _*)
-  .dependsOn(model)
+  .dependsOn(backend)
 
 lazy val `backend-ts` = project
   .in(file("backend/ts"))

cli/src/main/scala/aqua/AquaCompiler.scala

@@ -1,24 +1,22 @@
 package aqua
 
-import aqua.backend.air.FuncAirGen
-import aqua.backend.js.JavaScriptFile
-import aqua.backend.ts.TypescriptFile
-import aqua.io.{AquaFileError, AquaFiles, FileModuleId, Unresolvable}
+import aqua.backend.Backend
+import aqua.backend.air.AirBackend
+import aqua.backend.js.JavaScriptBackend
+import aqua.backend.ts.TypeScriptBackend
+import aqua.io._
 import aqua.linker.Linker
 import aqua.model.AquaContext
 import aqua.model.transform.BodyConfig
 import aqua.parser.lift.FileSpan
 import aqua.semantics.{RulesViolated, SemanticError, Semantics}
-import cats.Applicative
-import cats.data.Validated.{Invalid, Valid}
 import cats.data._
 import cats.effect.kernel.Concurrent
 import cats.kernel.Monoid
 import cats.syntax.flatMap._
 import cats.syntax.functor._
-import cats.syntax.show._
+import cats.{Applicative, Monad}
 import fs2.io.file.Files
-import fs2.text
 import wvlet.log.LogSupport
 
 import java.nio.file.Path
@@ -29,36 +27,38 @@ object AquaCompiler extends LogSupport {
   case object JavaScriptTarget extends CompileTarget
   case object AirTarget extends CompileTarget
 
-  case class Prepared(modFile: Path, srcPath: Path, targetPath: Path, context: AquaContext) {
-
-    def hasOutput(target: CompileTarget): Boolean = target match {
-      case _ => context.funcs.nonEmpty
+  private def gatherPreparedFiles(
+    srcPath: Path,
+    targetPath: Path,
+    files: Map[FileModuleId, ValidatedNec[SemanticError[FileSpan.F], AquaContext]]
+  ): ValidatedNec[String, Chain[Prepared]] = {
+    val (errs, _, preps) = files.toSeq.foldLeft[(Chain[String], Set[String], Chain[Prepared])](
+      (Chain.empty, Set.empty, Chain.empty)
+    ) { case ((errs, errsSet, preps), (modId, proc)) =>
+      proc.fold(
+        es => {
+          val newErrs = showProcErrors(es.toChain).filterNot(errsSet.contains)
+          (errs ++ newErrs, errsSet ++ newErrs.iterator, preps)
+        },
+        c => {
+          Prepared(modId.file, srcPath, targetPath, c) match {
+            case Validated.Valid(p) ⇒
+              (errs, errsSet, preps :+ p)
+            case Validated.Invalid(err) ⇒
+              (errs :+ err.getMessage, errsSet, preps)
           }
 
-    def targetPath(ext: String): Validated[Throwable, Path] =
-      Validated.catchNonFatal {
-        val srcDir = if (srcPath.toFile.isDirectory) srcPath else srcPath.getParent
-        val srcFilePath = srcDir.toAbsolutePath
-          .normalize()
-          .relativize(modFile.toAbsolutePath.normalize())
-
-        val targetAqua =
-          targetPath.toAbsolutePath
-            .normalize()
-            .resolve(
-              srcFilePath
+        }
       )
-
-        val fileName = targetAqua.getFileName
-        if (fileName == null) {
-          throw new Exception(s"Unexpected: 'fileName' is null in path $targetAqua")
-        } else {
-          // rename `.aqua` file name to `.ext`
-          targetAqua.getParent.resolve(fileName.toString.stripSuffix(".aqua") + s".$ext")
-        }
     }
+    NonEmptyChain
+      .fromChain(errs)
+      .fold(Validated.validNec[String, Chain[Prepared]](preps))(Validated.invalid)
   }
 
+  /**
+   * Create a structure that will be used to create output by a backend
+   */
   def prepareFiles[F[_]: Files: Concurrent](
     srcPath: Path,
     imports: LazyList[Path],
@@ -81,21 +81,7 @@ object AquaCompiler extends LogSupport {
             ids => Unresolvable(ids.map(_.id.file.toString).mkString(" -> "))
           ) match {
             case Validated.Valid(files) ⇒
-              val (errs, _, preps) =
-                files.toSeq.foldLeft[(Chain[String], Set[String], Chain[Prepared])](
-                  (Chain.empty, Set.empty, Chain.empty)
-                ) { case ((errs, errsSet, preps), (modId, proc)) =>
-                  proc.fold(
-                    es => {
-                      val newErrs = showProcErrors(es.toChain).filterNot(errsSet.contains)
-                      (errs ++ newErrs, errsSet ++ newErrs.iterator, preps)
-                    },
-                    c => (errs, errsSet, preps :+ Prepared(modId.file, srcPath, targetPath, c))
-                  )
-                }
-              NonEmptyChain
-                .fromChain(errs)
-                .fold(Validated.validNec[String, Chain[Prepared]](preps))(Validated.invalid)
+              gatherPreparedFiles(srcPath, targetPath, files)
 
             case Validated.Invalid(errs) ⇒
               Validated.invalid(
@@ -118,6 +104,38 @@ object AquaCompiler extends LogSupport {
         "Semantic error"
     }
 
+  def targetToBackend(target: CompileTarget): Backend = {
+    target match {
+      case TypescriptTarget =>
+        TypeScriptBackend
+      case JavaScriptTarget =>
+        JavaScriptBackend
+      case AirTarget =>
+        AirBackend
+    }
+  }
+
+  private def gatherResults[F[_]: Monad](
+    results: List[EitherT[F, String, Unit]]
+  ): F[Validated[NonEmptyChain[String], Chain[String]]] = {
+    results
+      .foldLeft(
+        EitherT.rightT[F, NonEmptyChain[String]](Chain.empty[String])
+      ) { case (accET, writeET) =>
+        EitherT(for {
+          acc <- accET.value
+          writeResult <- writeET.value
+        } yield (acc, writeResult) match {
+          case (Left(errs), Left(err)) => Left(errs :+ err)
+          case (Right(res), Right(_)) => Right(res)
+          case (Left(errs), _) => Left(errs)
+          case (_, Left(err)) => Left(NonEmptyChain.of(err))
+        })
+      }
+      .value
+      .map(Validated.fromEither)
+  }
+
   def compileFilesTo[F[_]: Files: Concurrent](
     srcPath: Path,
     imports: LazyList[Path],
@@ -129,69 +147,30 @@ object AquaCompiler extends LogSupport {
     prepareFiles(srcPath, imports, targetPath)
       .map(_.map(_.filter { p =>
         val hasOutput = p.hasOutput(compileTo)
-        if (!hasOutput) info(s"Source ${p.modFile}: compilation OK (nothing to emit)")
+        if (!hasOutput) info(s"Source ${p.srcFile}: compilation OK (nothing to emit)")
         hasOutput
       }))
       .flatMap[ValidatedNec[String, Chain[String]]] {
         case Validated.Invalid(e) =>
           Applicative[F].pure(Validated.invalid(e))
         case Validated.Valid(preps) =>
-          (compileTo match {
-            case TypescriptTarget =>
-              preps.map { p =>
-                p.targetPath("ts") match {
-                  case Invalid(t) =>
-                    EitherT.pure(t.getMessage)
-                  case Valid(tp) =>
-                    writeFile(tp, TypescriptFile(p.context).generateTS(bodyConfig)).flatTap { _ =>
-                      EitherT.pure(
-                        Validated.catchNonFatal(
-                          info(
-                            s"Result ${tp.toAbsolutePath}: compilation OK (${p.context.funcs.size} functions)"
-                          )
-                        )
-                      )
-                    }
-                }
-
-              }
-
-            case JavaScriptTarget =>
-              preps.map { p =>
-                p.targetPath("js") match {
-                  case Invalid(t) =>
-                    EitherT.pure(t.getMessage)
-                  case Valid(tp) =>
-                    writeFile(tp, JavaScriptFile(p.context).generateJS(bodyConfig)).flatTap { _ =>
-                      EitherT.pure(
-                        Validated.catchNonFatal(
-                          info(
-                            s"Result ${tp.toAbsolutePath}: compilation OK (${p.context.funcs.size} functions)"
-                          )
-                        )
-                      )
-                    }
-                }
-
-              }
-
-            // TODO add function name to AirTarget class
-            case AirTarget =>
-              preps
+          val backend = targetToBackend(compileTo)
+          val results = preps.toList
             .flatMap(p =>
-                  Chain
-                    .fromSeq(p.context.funcs.values.toSeq)
-                    .map(fc => fc.funcName -> FuncAirGen(fc).generateAir(bodyConfig).show)
-                    .map { case (fnName, generated) =>
-                      val tpV = p.targetPath(fnName + ".air")
-                      tpV match {
-                        case Invalid(t) =>
-                          EitherT.pure(t.getMessage)
-                        case Valid(tp) =>
-                          writeFile(
+              backend.generate(p.context, bodyConfig).map { compiled =>
+                val targetPath = p.targetPath(
+                  p.srcFile.getFileName.toString.stripSuffix(".aqua") + compiled.suffix
+                )
+
+                targetPath.fold(
+                  t => EitherT.leftT[F, Unit](t.getMessage),
+                  tp =>
+                    FileOps
+                      .writeFile(
                         tp,
-                            generated
-                          ).flatTap { _ =>
+                        compiled.content
+                      )
+                      .flatTap { _ =>
                         EitherT.pure(
                           Validated.catchNonFatal(
                             info(
@@ -200,45 +179,12 @@ object AquaCompiler extends LogSupport {
                           )
                         )
                       }
-                      }
+                )
               }
             )
 
-          }).foldLeft(
-            EitherT.rightT[F, NonEmptyChain[String]](Chain.empty[String])
-          ) { case (accET, writeET) =>
-            EitherT(for {
-              a <- accET.value
-              w <- writeET.value
-            } yield (a, w) match {
-              case (Left(errs), Left(err)) => Left(errs :+ err)
-              case (Right(res), Right(_)) => Right(res)
-              case (Left(errs), _) => Left(errs)
-              case (_, Left(err)) => Left(NonEmptyChain.of(err))
-            })
-          }.value
-            .map(Validated.fromEither)
-
+          gatherResults(results)
       }
   }
 
-  def writeFile[F[_]: Files: Concurrent](file: Path, content: String): EitherT[F, String, Unit] =
-    EitherT.right[String](Files[F].deleteIfExists(file)) >>
-      EitherT[F, String, Unit](
-        fs2.Stream
-          .emit(
-            content
-          )
-          .through(text.utf8Encode)
-          .through(Files[F].writeAll(file))
-          .attempt
-          .map { e =>
-            e.left
-              .map(t => s"Error on writing file $file" + t)
-          }
-          .compile
-          .drain
-          .map(_ => Right(()))
-      )
-
 }

cli/src/main/scala/aqua/Prepared.scala

@@ -0,0 +1,57 @@
+package aqua
+
+import aqua.AquaCompiler.CompileTarget
+import aqua.model.AquaContext
+import cats.data.Validated
+
+import java.nio.file.Path
+
+object Prepared {
+
+  /**
+   * @param srcFile aqua source
+   * @param srcPath a main source path with all aqua files
+   * @param targetPath a main path where all output files will be written
+   * @param context processed aqua code
+   * @return
+   */
+  def apply(
+    srcFile: Path,
+    srcPath: Path,
+    targetPath: Path,
+    context: AquaContext
+  ): Validated[Throwable, Prepared] =
+    Validated.catchNonFatal {
+      val srcDir = if (srcPath.toFile.isDirectory) srcPath else srcPath.getParent
+      val srcFilePath = srcDir.toAbsolutePath
+        .normalize()
+        .relativize(srcFile.toAbsolutePath.normalize())
+
+      val targetDir =
+        targetPath.toAbsolutePath
+          .normalize()
+          .resolve(
+            srcFilePath
+          )
+
+      new Prepared(targetDir, srcFile, context)
+    }
+}
+
+/**
+ * All info that can be used to write a final output.
+ * @param targetDir a directory to write to
+ * @param srcFile file with a source (aqua code)
+ * @param context processed code
+ */
+case class Prepared private (targetDir: Path, srcFile: Path, context: AquaContext) {
+
+  def hasOutput(target: CompileTarget): Boolean = target match {
+    case _ => context.funcs.nonEmpty
+  }
+
+  def targetPath(fileName: String): Validated[Throwable, Path] =
+    Validated.catchNonFatal {
+      targetDir.getParent.resolve(fileName)
+    }
+}

cli/src/main/scala/aqua/io/AquaFile.scala

@@ -10,7 +10,6 @@ import cats.effect.Concurrent
 import cats.syntax.apply._
 import cats.syntax.functor._
 import fs2.io.file.Files
-import fs2.text
 
 import java.nio.file.{Path, Paths}
 
@@ -54,27 +53,16 @@ case class AquaFile(
 
 object AquaFile {
 
-  def readSourceText[F[_]: Files: Concurrent](
+  def readAst[F[_]: Files: Concurrent](
     file: Path
-  ): fs2.Stream[F, Either[AquaFileError, String]] =
-    Files[F]
-      .readAll(file, 4096)
-      .fold(Vector.empty[Byte])((acc, b) => acc :+ b)
-      // TODO fix for comment on last line in air
-      // TODO should be fixed by parser
-      .map(_.appendedAll("\n\r".getBytes))
-      .flatMap(fs2.Stream.emits)
-      .through(text.utf8Decode)
-      .attempt
+  ): fs2.Stream[F, Either[AquaFileError, (String, Ast[FileSpan.F])]] =
+    FileOps
+      .readSourceText[F](file)
       .map {
         _.left
           .map(t => FileSystemError(t))
       }
-
-  def readAst[F[_]: Files: Concurrent](
-    file: Path
-  ): fs2.Stream[F, Either[AquaFileError, (String, Ast[FileSpan.F])]] =
-    readSourceText[F](file).map(
+      .map(
         _.flatMap(source =>
           Aqua
             .parseFileString(file.toString, source)

cli/src/main/scala/aqua/io/FileOps.scala

@@ -0,0 +1,47 @@
+package aqua.io
+
+import cats.data.EitherT
+import cats.effect.Concurrent
+import cats.implicits.toFunctorOps
+import fs2.io.file.Files
+import fs2.text
+
+import java.nio.file.Path
+
+object FileOps {
+
+  def writeFile[F[_]: Files: Concurrent](file: Path, content: String): EitherT[F, String, Unit] =
+    EitherT
+      .right[String](Files[F].deleteIfExists(file))
+      .flatMap(_ =>
+        EitherT[F, String, Unit](
+          fs2.Stream
+            .emit(
+              content
+            )
+            .through(text.utf8Encode)
+            .through(Files[F].writeAll(file))
+            .attempt
+            .map { e =>
+              e.left
+                .map(t => s"Error on writing file $file" + t)
+            }
+            .compile
+            .drain
+            .map(_ => Right(()))
+        )
+      )
+
+  def readSourceText[F[_]: Files: Concurrent](
+    file: Path
+  ): fs2.Stream[F, Either[Throwable, String]] =
+    Files[F]
+      .readAll(file, 4096)
+      .fold(Vector.empty[Byte])((acc, b) => acc :+ b)
+      // TODO fix for comment on last line in air
+      // TODO should be fixed by parser
+      .map(_.appendedAll("\n\r".getBytes))
+      .flatMap(fs2.Stream.emits)
+      .through(text.utf8Decode)
+      .attempt
+}

cli/src/test/aqua/test.aqua

@@ -0,0 +1,18 @@
+service CustomId("cid"):
+  id() -> string
+
+func first(node_id: string, viaAr: []string) -> string:
+    on node_id via viaAr:
+        p <- CustomId.id()
+    <- p
+
+
+func second(node_id: string, viaStr: *string) -> string:
+    on node_id via viaStr:
+        p <- CustomId.id()
+    <- p
+
+func third(relay: string, node_id: string, viaOpt: ?string) -> string:
+    on node_id via viaOpt:
+        p <- CustomId.id()
+    <- p

cli/src/test/scala/WriteFileSpec.scala

@@ -0,0 +1,60 @@
+import aqua.AquaCompiler
+import aqua.model.transform.BodyConfig
+import cats.effect.IO
+import cats.effect.unsafe.implicits.global
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+import java.nio.file.{Files, Paths}
+
+class WriteFileSpec extends AnyFlatSpec with Matchers {
+  "cli" should "compile aqua code in js" in {
+    val src = Paths.get("./cli/src/test/aqua")
+    val targetTs = Files.createTempDirectory("ts")
+    val targetJs = Files.createTempDirectory("js")
+    val targetAir = Files.createTempDirectory("air")
+
+    val bc = BodyConfig()
+    AquaCompiler
+      .compileFilesTo[IO](src, LazyList.empty, targetTs, AquaCompiler.TypescriptTarget, bc)
+      .unsafeRunSync()
+      .leftMap { err =>
+        println(err)
+        err
+      }
+      .isValid should be(true)
+    val targetTsFile = targetTs.resolve("test.ts")
+    targetTsFile.toFile.exists() should be(true)
+    Files.deleteIfExists(targetTsFile)
+
+    AquaCompiler
+      .compileFilesTo[IO](src, LazyList.empty, targetJs, AquaCompiler.JavaScriptTarget, bc)
+      .unsafeRunSync()
+      .leftMap { err =>
+        println(err)
+        err
+      }
+      .isValid should be(true)
+    val targetJsFile = targetJs.resolve("test.js")
+    targetJsFile.toFile.exists() should be(true)
+    Files.deleteIfExists(targetJsFile)
+
+    AquaCompiler
+      .compileFilesTo[IO](src, LazyList.empty, targetAir, AquaCompiler.AirTarget, bc)
+      .unsafeRunSync()
+      .leftMap { err =>
+        println(err)
+        err
+      }
+      .isValid should be(true)
+    val targetAirFileFirst = targetAir.resolve("test.first.air")
+    val targetAirFileSecond = targetAir.resolve("test.second.air")
+    val targetAirFileThird = targetAir.resolve("test.third.air")
+    targetAirFileFirst.toFile.exists() should be(true)
+    targetAirFileSecond.toFile.exists() should be(true)
+    targetAirFileThird.toFile.exists() should be(true)
+
+    Seq(targetAirFileFirst, targetAirFileSecond, targetAirFileThird).map(Files.deleteIfExists)
+  }
+
+}

model/test-kit/src/test/scala/aqua/model/topology/TopologySpec.scala

@@ -4,7 +4,7 @@ import aqua.Node
 import aqua.model.VarModel
 import aqua.model.func.Call
 import aqua.model.func.raw.FuncOps
-import aqua.model.func.resolved.{MakeRes, ResolvedOp, SeqRes, XorRes}
+import aqua.model.func.resolved.{MakeRes, ResolvedOp, XorRes}
 import aqua.types.ScalarType
 import cats.Eval
 import cats.data.Chain
@@ -295,31 +295,10 @@ class TopologySpec extends AnyFlatSpec with Matchers {
         callRes(2, initPeer)
       )
 
-//    println(Console.BLUE + init)
-//    println(Console.YELLOW + proc)
-//    println(Console.MAGENTA + expected)
-//    println(Console.RESET)
-
     proc.equalsOrPrintDiff(expected) should be(true)
   }
 
   "topology resolver" should "not stackoverflow" in {
-    /*
-    OnTag(LiteralModel(%init_peer_id%,ScalarType(string)),Chain(VarModel(-relay-,ScalarType(string),Chain()))) {
-        SeqTag{
-          CallServiceTag(LiteralModel("getDataSrv",ScalarType(string)),-relay-,Call(List(),Some(Export(-relay-,ScalarType(string)))),None)
-          CallServiceTag(LiteralModel("getDataSrv",ScalarType(string)),node_id,Call(List(),Some(Export(node_id,ScalarType(string)))),None)
-          CallServiceTag(LiteralModel("getDataSrv",ScalarType(string)),viaAr,Call(List(),Some(Export(viaAr,[]ScalarType(string)))),None)
-          OnTag(VarModel(node_id,ScalarType(string),Chain()),Chain(VarModel(viaAr,[]ScalarType(string),Chain()))) {
-            CallServiceTag(LiteralModel("cid",Literal(string)),ids,Call(List(),Some(Export(p,ScalarType(string)))),None)
-          }
-          OnTag(LiteralModel(%init_peer_id%,ScalarType(string)),Chain(VarModel(-relay-,ScalarType(string),Chain()))) {
-            CallServiceTag(LiteralModel("callbackSrv",ScalarType(string)),response,Call(List(VarModel(p,ScalarType(string),Chain())),None),None)
-          }
-        }
-      }
-
-     */
     val init = on(
       initPeer,
       relay :: Nil,
@@ -394,11 +373,6 @@ class TopologySpec extends AnyFlatSpec with Matchers {
         callRes(3, initPeer)
       )
 
-//    println(Console.BLUE + init)
-//    println(Console.YELLOW + proc)
-//    println(Console.MAGENTA + expected)
-//    println(Console.RESET)
-
     proc.equalsOrPrintDiff(expected) should be(true)
   }
 
@@ -453,11 +427,6 @@ class TopologySpec extends AnyFlatSpec with Matchers {
         callRes(4, initPeer)
       )
 
-//    println(Console.BLUE + init)
-    println(Console.YELLOW + proc)
-    println(Console.MAGENTA + expected)
-    println(Console.RESET)
-
     Node.equalsOrPrintDiff(proc, expected) should be(true)
   }
 

parser/src/test/scala/aqua/parser/CoExprSpec.scala

@@ -0,0 +1,35 @@
+package aqua.parser
+
+import aqua.AquaSpec
+import aqua.parser.expr.{CallArrowExpr, CoExpr}
+import aqua.parser.lexer.Token
+import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import cats.data.Chain
+import cats.free.Cofree
+import cats.{Eval, Id}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+class CoExprSpec extends AnyFlatSpec with Matchers with AquaSpec {
+
+  "co" should "be parsed" in {
+    CoExpr.readLine[Id].parseAll("co x <- y()").value should be(
+      Cofree[Chain, Expr[Id]](
+        CoExpr[Id](Token.lift[Id, Unit](())),
+        Eval.now(
+          Chain(
+            Cofree[Chain, Expr[Id]](
+              CallArrowExpr(
+                Some(AquaSpec.toName("x")),
+                None,
+                AquaSpec.toName("y"),
+                Nil
+              ),
+              Eval.now(Chain.empty)
+            )
+          )
+        )
+      )
+    )
+  }
+}