Improve error reporting when running DAML Script over the JSON API (#6481)

It is pretty easy to hit this, e.g., when your templates haven’t been
uploaded to the ledger. Just printing the response doesn’t actually
include the response body which means that you don’t see the actual
error so it’s pretty useless. This PR changes that by printing the
status code and the response body.

All the rest is just test setup to be able to submit a script with a
template that has not been uploaded to the ledger.

changelog_begin
changelog_end

daml-script/runner/src/main/scala/com/digitalasset/daml/lf/engine/script/LedgerInteraction.scala

@@ -579,9 +579,13 @@ class JsonLedgerClient(
         getResponseDataBytes(resp).map(description =>
           Left(new StatusRuntimeException(Status.UNKNOWN.withDescription(description))))
       } else {
-        // A non-500 failure is something like invalid JSON. In that case
-        // the script runner is just broken so fail hard.
-        Future.failed(new RuntimeException(s"Request failed: $resp"))
+        // A non-500 failure is something like invalid JSON or “cannot resolve template ID”.
+        // We don’t want to treat that failures as ones that can be caught
+        // via `submitMustFail` so fail hard.
+        getResponseDataBytes(resp).flatMap(
+          description =>
+            Future.failed(
+              new RuntimeException(s"Request failed: $description, status code: ${resp.status}")))
       }
     }
   }

daml-script/test/BUILD.bazel

@@ -47,6 +47,39 @@ EOF
     visibility = ["//visibility:public"],
 )
 
+# A variant of script-test that has not been uploaded to the ledger
+# to test missing template ids. We only care that this has a different package id.
+genrule(
+    name = "script-test-no-ledger",
+    srcs =
+        glob(["**/*.daml"]) + [
+            "//daml-script/daml:daml-script.dar",
+            "//docs:source/daml-script/template-root/src/ScriptExample.daml",
+        ],
+    outs = ["script-test-no-ledger.dar"],
+    cmd = """
+      set -eou pipefail
+      TMP_DIR=$$(mktemp -d)
+      mkdir -p $$TMP_DIR/daml
+      cp -L $(location :daml/ScriptTest.daml) $$TMP_DIR/daml
+      cp -L $(location //daml-script/daml:daml-script.dar) $$TMP_DIR/
+      cat << EOF > $$TMP_DIR/daml.yaml
+sdk-version: {sdk}
+name: script-test-no-ledger
+source: daml
+version: 0.0.2
+dependencies:
+  - daml-stdlib
+  - daml-prim
+  - daml-script.dar
+EOF
+      $(location //compiler/damlc) build --project-root=$$TMP_DIR -o $$PWD/$(location script-test-no-ledger.dar)
+      rm -rf $$TMP_DIR
+    """.format(sdk = sdk_version),
+    tools = ["//compiler/damlc"],
+    visibility = ["//visibility:public"],
+)
+
 da_scala_library(
     name = "test-lib",
     srcs = glob(
@@ -95,7 +128,10 @@ da_scala_test_suite(
     srcs = [
         "src/com/digitalasset/daml/lf/engine/script/test/JsonApiIt.scala",
     ],
-    data = [":script-test.dar"],
+    data = [
+        ":script-test.dar",
+        ":script-test-no-ledger.dar",
+    ],
     resources = glob(["src/main/resources/**/*"]),
     deps = [
         ":test-lib",

daml-script/test/daml/ScriptTest.daml

@@ -236,6 +236,11 @@ jsonMultiParty (alice, bob) = do
   submit bob (exerciseCmd c Accept)
   pure ()
 
+jsonMissingTemplateId : Party -> Script Int
+jsonMissingTemplateId p = do
+  cid <- submit p (createCmd $ TProposal p p)
+  snd <$> submit p (exerciseCmd cid Accept)
+
 -- maxInboundMessageSize
 
 template MessageSize

daml-script/test/src/com/digitalasset/daml/lf/engine/script/test/JsonApiIt.scala

@@ -16,7 +16,7 @@ import scalaz.syntax.traverse._
 import spray.json._
 
 import com.daml.bazeltools.BazelRunfiles._
-import com.daml.lf.archive.DarReader
+import com.daml.lf.archive.{Dar, DarReader}
 import com.daml.lf.archive.Decode
 import com.daml.lf.data.Ref._
 import com.daml.lf.engine.script.{
@@ -30,6 +30,7 @@ import com.daml.lf.engine.script.{
 }
 import com.daml.lf.iface.EnvironmentInterface
 import com.daml.lf.iface.reader.InterfaceReader
+import com.daml.lf.language.Ast.Package
 import com.daml.lf.speedy.SError._
 import com.daml.lf.speedy.SValue
 import com.daml.lf.speedy.SValue._
@@ -61,6 +62,7 @@ trait JsonApiFixture
   self: Suite =>
 
   override protected def darFile = new File(rlocation("daml-script/test/script-test.dar"))
+  protected val darFileNoLedger = new File(rlocation("daml-script/test/script-test-no-ledger.dar"))
   protected def server: SandboxServer = suiteResource.value._1
   override protected def serverPort: Port = server.port
   override protected def channel: Channel = suiteResource.value._2
@@ -134,11 +136,17 @@ final class JsonApiIt
     with SuiteResourceManagementAroundAll
     with TryValues {
 
-  private val dar = DarReader().readArchiveFromFile(darFile).get.map {
-    case (pkgId, archive) => Decode.readArchivePayload(pkgId, archive)
+  private def readDar(file: File): (Dar[(PackageId, Package)], EnvironmentInterface) = {
+    val dar = DarReader().readArchiveFromFile(file).get.map {
+      case (pkgId, archive) => Decode.readArchivePayload(pkgId, archive)
+    }
+    val ifaceDar = dar.map(pkg => InterfaceReader.readInterface(() => \/-(pkg))._2)
+    val envIface = EnvironmentInterface.fromReaderInterfaces(ifaceDar)
+    (dar, envIface)
   }
-  private val ifaceDar = dar.map(pkg => InterfaceReader.readInterface(() => \/-(pkg))._2)
-  private val envIface = EnvironmentInterface.fromReaderInterfaces(ifaceDar)
+
+  val (dar, envIface) = readDar(darFile)
+  val (darNoLedger, envIfaceNoLedger) = readDar(darFileNoLedger)
 
   def getToken(parties: List[String], admin: Boolean): String = {
     val payload = AuthServiceJWTPayload(
@@ -161,7 +169,8 @@ final class JsonApiIt
   private def getClients(
       parties: List[String] = List(party),
       defaultParty: Option[String] = None,
-      admin: Boolean = false) = {
+      admin: Boolean = false,
+      envIface: EnvironmentInterface = envIface) = {
     // We give the default participant some nonsense party so the checks for party mismatch fail
     // due to the mismatch and not because the token does not allow inferring a party
     val defaultParticipant =
@@ -183,8 +192,9 @@ final class JsonApiIt
   private def run(
       clients: Participants[ScriptLedgerClient],
       name: QualifiedName,
-      inputValue: Option[JsValue] = Some(JsString(party))): Future[SValue] = {
-    val scriptId = Identifier(packageId, name)
+      inputValue: Option[JsValue] = Some(JsString(party)),
+      dar: Dar[(PackageId, Package)] = dar): Future[SValue] = {
+    val scriptId = Identifier(dar.main._1, name)
     Runner.run(
       dar,
       scriptId,
@@ -305,5 +315,18 @@ final class JsonApiIt
         assert(result == SUnit)
       }
     }
+    "missing template id" in {
+      for {
+        clients <- getClients(envIface = envIfaceNoLedger)
+        ex <- recoverToExceptionIf[RuntimeException](
+          run(
+            clients,
+            QualifiedName.assertFromString("ScriptTest:jsonMissingTemplateId"),
+            dar = darNoLedger
+          ))
+      } yield {
+        assert(ex.toString.contains("Cannot resolve template ID"))
+      }
+    }
   }
 }