test(alchemist-loading): add regression test for jsr variable failing when using external variables

alchemist-loading/src/test/kotlin/it/unibo/alchemist/test/TestKtVariable.kt

@@ -77,4 +77,15 @@ class TestKtVariable<T, P : Position<P>> :
             assertNotNull(loader.getWith<T, P>(emptyMap<String, String>()))
             loader.variables["seed"] shouldNot beNull()
         }
+
+        // This is a regression test, when using Alchemist variables inside a JSR223Variable scope,
+        // the simulation does not inherit the external variables into the JSR scope.
+        // Caused by: javax.script.ScriptException: ERROR Unresolved reference: *externalVariableName*
+        "simulation should load external variables inside function scope" {
+            val file = ResourceLoader.getResource("regression/testJSRVariable.yml")
+            assertNotNull(file)
+            val loader = LoadAlchemist.from(file)
+            assertNotNull(loader.getWith<T, P>(emptyMap<String, String>()))
+            loader.variables["simple"] shouldNot beNull()
+        }
     })

alchemist-loading/src/test/resources/regression/testJSRVariable.yml

@@ -0,0 +1,14 @@
+incarnation: sapere
+
+_constants:
+  name: "test"
+
+variables:
+  number: 1
+  other:
+    type: ArbitraryVariable
+    parameters: [ 1, [1, 2]]
+  simple: &simple
+    language: kotlin
+    formula: |
+      val couple: Pair<Int, String> = (number + other) to name