fix(compiler): Handle errors from result handling [fixes LNG-247] (#913)

Move args and return under try

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

@@ -159,10 +159,10 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers {
     val retVar = VarModel("ret", ScalarType.string)
 
     val expected =
-      SeqRes.wrap(
-        getDataSrv("-relay-", "-relay-", ScalarType.string),
-        getDataSrv("peers", peers.name, peers.`type`),
-        XorRes.wrap(
+      XorRes.wrap(
+        SeqRes.wrap(
+          getDataSrv("-relay-", "-relay-", ScalarType.string),
+          getDataSrv("peers", peers.name, peers.`type`),
           RestrictionRes(results.name, resultsType).wrap(
             SeqRes.wrap(
               ParRes.wrap(
@@ -203,9 +203,9 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers {
               ).leaf
             )
           ),
-          errorCall(transformCfg, 0, initPeer)
+          respCall(transformCfg, flatResult, initPeer)
         ),
-        respCall(transformCfg, flatResult, initPeer)
+        errorCall(transformCfg, 0, initPeer)
       )
 
     exec.body.equalsOrShowDiff(expected) shouldBe (true)
@@ -276,8 +276,8 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers {
     val resCanonVM = VarModel("-res-fix-0", CanonStreamType(ScalarType.string))
     val resFlatVM = VarModel("-res-flat-0", ArrayType(ScalarType.string))
 
-    val expected = SeqRes.wrap(
-      XorRes.wrap(
+    val expected = XorRes.wrap(
+      SeqRes.wrap(
         RestrictionRes(resVM.name, resStreamType).wrap(
           SeqRes.wrap(
             // res <- foo()
@@ -303,9 +303,9 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers {
             ).leaf
           )
         ),
-        errorCall(transformCfg, 0, initPeer)
+        respCall(transformCfg, resFlatVM, initPeer)
       ),
-      respCall(transformCfg, resFlatVM, initPeer)
+      errorCall(transformCfg, 0, initPeer)
     )
 
     barfoo.body.equalsOrShowDiff(expected) should be(true)

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

@@ -9,7 +9,22 @@ import aqua.types.*
 import cats.syntax.show.*
 import cats.syntax.option.*
 
-// TODO: doc
+/**
+ * Pre-transformer for top functions:
+ * - Get arguments
+ * - Get relay
+ * - Generate callbacks for function arguments
+ * - Handle result
+ * - Handle error
+ *
+ * @param argsProvider - provides arguments
+ * @param resultsHandler - handles results
+ * @param errorHandler - handles errors
+ * @param callback - generates callback for function argument
+ * @param relayVarName - name of the relay variable
+ * @param wrapCallableName - name of the generated wrapper function
+ * @param arrowCallbackPrefix - prefix for generated callbacks names
+ */
 case class FuncPreTransformer(
   argsProvider: ArgsProvider,
   resultsHandler: ResultsHandler,
@@ -50,7 +65,7 @@ case class FuncPreTransformer(
    * removes function return
    *
    * @param func Function to transform
-   * @return
+   * @return Transformed function
    */
   def preTransform(func: FuncArrow): FuncArrow = {
     val returnType = ProductType(func.ret.map(_.`type`).map {
@@ -93,13 +108,13 @@ case class FuncPreTransformer(
 
     val call = CallArrowRawTag.func(func.funcName, funcCall).leaf
 
-    val body = SeqTag.wrap(
-      provideArgs ++ List(
-        TryTag.wrap(
-          call,
-          handleError
-        )
-      ) ++ handleResults
+    val body = TryTag.wrap(
+      SeqTag.wrap(
+        provideArgs
+          .appended(call)
+          .appendedAll(handleResults)
+      ),
+      handleError
     )
 
     FuncArrow(

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

@@ -48,29 +48,28 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
     val procFC = fc.value.body
 
-    val expectedFC =
+    val expectedFC = XorRes.wrap(
       SeqRes.wrap(
         dataCall(bc, "-relay-", initPeer),
         XorRes.wrap(
-          XorRes.wrap(
-            SeqRes.wrap(
-              through(relayV),
-              through(otherRelay),
-              callRes(1, otherPeer),
-              through(otherRelay),
-              through(relayV)
-            ),
-            SeqRes.wrap(
-              through(otherRelay),
-              through(relayV),
-              through(initPeer),
-              failErrorRes
-            )
+          SeqRes.wrap(
+            through(relayV),
+            through(otherRelay),
+            callRes(1, otherPeer),
+            through(otherRelay),
+            through(relayV)
           ),
-          errorCall(bc, 0, initPeer)
+          SeqRes.wrap(
+            through(otherRelay),
+            through(relayV),
+            through(initPeer),
+            failErrorRes
+          )
         ),
         respCall(bc, ret, initPeer)
-      )
+      ),
+      errorCall(bc, 0, initPeer)
+    )
 
     procFC.equalsOrShowDiff(expectedFC) should be(true)
 
@@ -80,9 +79,21 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
     val ret = LiteralRaw.quote("return this")
 
+    /**
+     * func ret() -> string:
+     *   srv0.fn0()
+     *   on "other-peer":
+     *     srv1.fn1()
+     *   <- "return this"
+     */
     val func: FuncArrow = FuncArrow(
       "ret",
-      SeqTag.wrap(callOp(0).leaf, OnTag(otherPeer, Chain.empty).wrap(callOp(1).leaf)),
+      SeqTag.wrap(
+        callOp(0).leaf,
+        OnTag(otherPeer, Chain.empty).wrap(
+          callOp(1).leaf
+        )
+      ),
       stringArrow,
       ret :: Nil,
       Map.empty,
@@ -96,29 +107,26 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
     val procFC = fc.value.body
 
-    val expectedFC =
+    val expectedFC = XorRes.wrap(
       SeqRes.wrap(
         dataCall(bc, "-relay-", initPeer),
+        callRes(0, initPeer),
         XorRes.wrap(
           SeqRes.wrap(
-            callRes(0, initPeer),
-            XorRes.wrap(
-              SeqRes.wrap(
-                through(relayV),
-                callRes(1, otherPeer),
-                through(relayV)
-              ),
-              SeqRes.wrap(
-                through(relayV),
-                through(initPeer),
-                failErrorRes
-              )
-            )
+            through(relayV),
+            callRes(1, otherPeer),
+            through(relayV)
           ),
-          errorCall(bc, 0, initPeer)
+          SeqRes.wrap(
+            through(relayV),
+            through(initPeer),
+            failErrorRes
+          )
         ),
         respCall(bc, ret, initPeer)
-      )
+      ),
+      errorCall(bc, 0, initPeer)
+    )
 
     procFC.equalsOrShowDiff(expectedFC) should be(true)
 
@@ -126,13 +134,13 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
   "transform.forClient" should "link funcs correctly" in {
     /*
-    func one() -> u64:
-      variable <- Demo.get42()
-      <- variable
+    func f1() -> string:
+      v <- srv1.fn1()
+      <- v
 
-    func two() -> u64:
-      variable <- one()
-      <- variable
+    func f2() -> string:
+      v <- f1()
+      <- v
      */
 
     val f1: FuncArrow =
@@ -163,13 +171,13 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
     val procFC = Transform.funcRes(f2, bc).value.body
 
-    val expectedFC = SeqRes.wrap(
-      dataCall(bc, "-relay-", initPeer),
-      XorRes.wrap(
+    val expectedFC = XorRes.wrap(
+      SeqRes.wrap(
+        dataCall(bc, "-relay-", initPeer),
         callRes(1, initPeer),
-        errorCall(bc, 0, initPeer)
+        respCall(bc, VarRaw("v", ScalarType.string), initPeer)
       ),
-      respCall(bc, VarRaw("v", ScalarType.string), initPeer)
+      errorCall(bc, 0, initPeer)
     )
 
     procFC.equalsOrShowDiff(expectedFC) should be(true)