test: Verify variable access in filter expression

Add a test case to verify that a list filter expression can access an item property and the property is not overridden by a variable with the same name.

(cherry picked from commit a61f15e)

src/test/scala/org/camunda/feel/impl/interpreter/InterpreterListExpressionTest.scala

@@ -17,6 +17,7 @@
 package org.camunda.feel.impl.interpreter
 
 import org.camunda.feel.api.EvaluationFailureType
+import org.camunda.feel.context.{CustomContext, VariableProvider}
 import org.camunda.feel.impl.{EvaluationResultMatchers, FeelEngineTest}
 import org.camunda.feel.syntaxtree._
 import org.scalatest.flatspec.AnyFlatSpec
@@ -400,4 +401,36 @@ class InterpreterListExpressionTest
     )
   }
 
+  "A filter expression" should "access an item property if the context contains a variable with the same name" in {
+    evaluateExpression(
+      expression =
+        """sum({"loans" : [
+                           {"loanId" : "AAA001", "amount" : 10},
+                           {"loanId" : "AAA002", "amount" : 20},
+                           {"loanId" : "AAA001", "amount" : 50}
+                         ]}.loans[loanId = id].amount)""",
+      variables = Map("id" -> "AAA002", "loanId" -> "AAA002")
+    ) should returnResult(20)
+  }
+
+  it should "access an item property if the custom context contains a variable with the same name" in {
+    evaluateExpression(
+      expression =
+        """sum({"loans" : [
+                           {"loanId" : "AAA001", "amount" : 10},
+                           {"loanId" : "AAA002", "amount" : 20},
+                           {"loanId" : "AAA001", "amount" : 50}
+                         ]}.loans[loanId = id].amount)""",
+      context = new MyContext(Map("id" -> "AAA002", "loanId" -> "AAA002"))
+    ) should returnResult(20)
+  }
+
+  class MyContext(val vars: Map[String, Any]) extends CustomContext {
+    override def variableProvider: VariableProvider = new VariableProvider {
+      override def getVariable(name: String): Option[Any] = vars.get(name)
+
+      override def keys: Iterable[String] = vars.keys
+    }
+  }
+
 }