[NU-1935] Change record indexer behaviour

docs/Changelog.md

@@ -58,6 +58,7 @@
 * [#7364](https://github.com/TouK/nussknacker/pull/7364) PeriodicDeploymentManger is no longer a separate DM, but instead is an optional functionality and decorator for all DMs
   * in order to use it, DM must implement interface `schedulingSupported`, that handles deployments on a specific engine
   * implementation provided for Flink DM
+* [#7443](https://github.com/TouK/nussknacker/pull/7443) Indexing on record is more similar to indexing on map. The change lets us access record values dynamically. For example now spel expression "{a: 5, b: 10}[#input.field]" compiles and has type "Integer" inferred from types of values of the record. This lets us access record value based on user input, for instance if user passes "{"field": "b"}" to scenario we will get value "10", whereas input {"field": "c"} would result in "null". Expression "{a: 5}["b"]" still does not compile because it is known at compile time that record does not have property "b".
 
 ## 1.18
 

scenario-compiler/src/main/scala/pl/touk/nussknacker/engine/spel/SpelExpressionParseError.scala

@@ -106,6 +106,10 @@ object SpelExpressionParseError {
       override def message: String = s"There is no property '$property' in type: ${typ.display}"
     }
 
+    case class NoPropertyTypeError(typ: TypingResult, propertyType: TypingResult) extends MissingObjectError {
+      override def message: String = s"There is no property of type '${propertyType.display}' in type: ${typ.display}"
+    }
+
     case class UnknownMethodError(methodName: String, displayableType: String) extends MissingObjectError {
       override def message: String = s"Unknown method '$methodName' in $displayableType"
     }

scenario-compiler/src/main/scala/pl/touk/nussknacker/engine/spel/Typer.scala

@@ -26,6 +26,7 @@ import pl.touk.nussknacker.engine.spel.SpelExpressionParseError.IllegalOperation
 import pl.touk.nussknacker.engine.spel.SpelExpressionParseError.MissingObjectError.{
   ConstructionOfUnknown,
   NoPropertyError,
+  NoPropertyTypeError,
   NonReferenceError,
   UnresolvedReferenceError
 }
@@ -199,11 +200,16 @@ private[spel] class Typer(
             case _                                      => typeFieldNameReferenceOnRecord(indexString, record)
           }
         case indexKey :: Nil if indexKey.canBeConvertedTo(Typed[String]) =>
-          if (dynamicPropertyAccessAllowed) valid(Unknown) else invalid(DynamicPropertyAccessError)
-        case _ :: Nil =>
+          if (dynamicPropertyAccessAllowed) valid(Unknown)
+          else
+            record.runtimeObjType.params match {
+              case _ :: value :: Nil if record.runtimeObjType.klass == classOf[java.util.Map[_, _]] => valid(value)
+              case _                                                                                => valid(Unknown)
+            }
+        case e :: Nil =>
           indexer.children match {
             case (ref: PropertyOrFieldReference) :: Nil => typeFieldNameReferenceOnRecord(ref.getName, record)
-            case _ => if (dynamicPropertyAccessAllowed) valid(Unknown) else invalid(DynamicPropertyAccessError)
+            case _ => if (dynamicPropertyAccessAllowed) valid(Unknown) else invalid(NoPropertyTypeError(record, e))
           }
         case _ =>
           invalid(IllegalIndexingOperation)

scenario-compiler/src/test/scala/pl/touk/nussknacker/engine/spel/SpelExpressionSpec.scala

@@ -272,6 +272,15 @@ class SpelExpressionSpec extends AnyFunSuite with Matchers with ValidatedValuesD
   private def evaluate[T: TypeTag](expr: String, context: Context = ctx): T =
     parse[T](expr = expr, context = context).validExpression.evaluateSync[T](context)
 
+  test("should be able to dynamically index record") {
+    evaluate[Int]("{a: 5, b: 10}[#input.toString()]", Context("abc").withVariable("input", "a")) shouldBe 5
+    evaluate[Integer]("{a: 5, b: 10}[#input.toString()]", Context("abc").withVariable("input", "asdf")) shouldBe null
+  }
+
+  test("should figure out result type when dynamically indexing record") {
+    evaluate[Int]("{a: {g: 5, h: 10}, b: {g: 50, h: 100}}[#input.toString()].h", Context("abc").withVariable("input", "b")) shouldBe 100
+  }
+
   test("parsing first selection on array") {
     parse[Any]("{1,2,3,4,5,6,7,8,9,10}.^[(#this%2==0)]").validExpression
       .evaluateSync[java.util.ArrayList[Int]](ctx) should equal(2)

scenario-compiler/src/test/scala/pl/touk/nussknacker/engine/spel/TyperSpec.scala

@@ -13,8 +13,10 @@ import pl.touk.nussknacker.engine.api.typed.typing._
 import pl.touk.nussknacker.engine.definition.clazz.ClassDefinitionTestUtils
 import pl.touk.nussknacker.engine.dict.{KeysDictTyper, SimpleDictRegistry}
 import pl.touk.nussknacker.engine.expression.PositionRange
-import pl.touk.nussknacker.engine.spel.SpelExpressionParseError.IllegalOperationError.DynamicPropertyAccessError
-import pl.touk.nussknacker.engine.spel.SpelExpressionParseError.MissingObjectError.NoPropertyError
+import pl.touk.nussknacker.engine.spel.SpelExpressionParseError.MissingObjectError.{
+  NoPropertyError,
+  NoPropertyTypeError
+}
 import pl.touk.nussknacker.engine.spel.SpelExpressionParseError.UnsupportedOperationError.MapWithExpressionKeysError
 import pl.touk.nussknacker.engine.spel.Typer.TypingResultWithContext
 import pl.touk.nussknacker.engine.spel.TyperSpecTestData.TestRecord._
@@ -162,10 +164,8 @@ class TyperSpec extends AnyFunSuite with Matchers with ValidatedValuesDetailedMe
     typeExpression(s"$testRecordExpr[#var]", "var" -> s"$nonPresentKey").invalidValue.toList should matchPattern {
       case NoPropertyError(typingResult, key) :: Nil if typingResult == testRecordTyped && key == nonPresentKey =>
     }
-    // TODO: this behavior is to be fixed - ideally this should behave the same as above
     typeExpression(s"$testRecordExpr[$nonPresentKey]").invalidValue.toList should matchPattern {
-      case NoPropertyError(typingResult, key) :: DynamicPropertyAccessError :: Nil
-          if typingResult == testRecordTyped && key == nonPresentKey =>
+      case NoPropertyError(typingResult, key) :: Nil if typingResult == testRecordTyped && key == nonPresentKey =>
     }
   }
 
@@ -183,6 +183,17 @@ class TyperSpec extends AnyFunSuite with Matchers with ValidatedValuesDetailedMe
     }
   }
 
+  test("indexing on records with key which is not known at compile time treats record as map") {
+    typeExpression("{a: 5, b: 10}[#var.toString()]", "var" -> "a").validValue.finalResult.typingResult shouldBe Typed
+      .typedClass[Int]
+  }
+
+  test("indexing on records with non string key produces error") {
+    typeExpression("{a: 5, b: 10}[4]").invalidValue.toList should matchPattern {
+      case NoPropertyTypeError(_, _) :: Nil =>
+    }
+  }
+
   private def buildTyper(dynamicPropertyAccessAllowed: Boolean = false) = new Typer(
     dictTyper = new KeysDictTyper(new SimpleDictRegistry(Map.empty)),
     strictMethodsChecking = false,