Persisting literal values more conservativly (#1907)

* Persisting literal values more conservativly

Fixes issues with python interface files

* Avoid toString() call for strings

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/statements/expressions/Literal.kt

@@ -60,10 +60,14 @@ class Literal<T> : Expression() {
 
 class ValueConverter : AttributeConverter<Any?, Any?> {
     override fun toGraphProperty(value: Any?): Any? {
-        return if (value is BigInteger) {
-            value.toString()
-        } else {
-            value
+        // Neo4J only supports a limited set of primitive values natively, everything else, we need
+        // to convert to a string.
+        return when (value) {
+            null -> null
+            (value is Number && value !is BigInteger) -> value
+            is Boolean -> value
+            is String -> value
+            else -> value.toString()
         }
     }
 

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/persistence/Common.kt

@@ -31,7 +31,6 @@ import de.fraunhofer.aisec.cpg.graph.Persistable
 import de.fraunhofer.aisec.cpg.graph.edges.collections.EdgeCollection
 import de.fraunhofer.aisec.cpg.graph.edges.collections.EdgeList
 import de.fraunhofer.aisec.cpg.helpers.neo4j.NameConverter
-import java.math.BigInteger
 import kotlin.reflect.KClass
 import kotlin.reflect.KProperty1
 import kotlin.reflect.KTypeProjection
@@ -134,8 +133,6 @@ fun Any.convert(
         properties.put(originalKey, this.name)
     } else if (this is Uuid) {
         properties.put(originalKey, this.toString())
-    } else if (this is BigInteger) {
-        properties.put(originalKey, this.toString())
     } else {
         properties.put(originalKey, this)
     }