adding check for non-sealed interface in MarkersExtractor for a Marker to be isOpen.

Extra check for isOpen in getAllSuperMarkers

Author: Jolanrensen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/codeGen/MarkersExtractor.kt

@@ -37,7 +37,10 @@ internal object MarkersExtractor {
     fun get(markerClass: KClass<*>, nullableProperties: Boolean = false): Marker =
         cache.getOrPut(Pair(markerClass, nullableProperties)) {
             val fields = getFields(markerClass, nullableProperties)
-            val isOpen = markerClass.findAnnotation<DataSchema>()?.isOpen ?: false
+            val isOpen = !markerClass.isSealed &&
+                markerClass.java.isInterface &&
+                markerClass.findAnnotation<DataSchema>()?.isOpen == true
+
             val baseSchemas = markerClass.superclasses.filter { it != Any::class }.map { get(it, nullableProperties) }
             Marker(
                 name = markerClass.qualifiedName ?: markerClass.simpleName!!,

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/codeGen/ReplCodeGeneratorImpl.kt

@@ -92,9 +92,7 @@ internal class ReplCodeGeneratorImpl : ReplCodeGenerator {
             extensionProperties = true,
             isOpen = isOpen,
             visibility = MarkerVisibility.IMPLICIT_PUBLIC,
-            knownMarkers = registeredMarkers
-                .filterKeys { !it.isData } // filter out data classes, so they aren't used as supertypes
-                .values,
+            knownMarkers = registeredMarkers.values,
         )
 
         result.newMarkers.forEach {

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/codeGen/SchemaProcessorImpl.kt

@@ -22,7 +22,7 @@ internal class SchemaProcessorImpl(
     override val generatedMarkers = mutableListOf<Marker>()
 
     private fun DataFrameSchema.getAllSuperMarkers() = registeredMarkers
-        .filter { it.schema.compare(this).isSuperOrEqual() }
+        .filter { it.isOpen && it.schema.compare(this).isSuperOrEqual() }
 
     private fun List<Marker>.onlyLeafs(): List<Marker> {
         val skip = flatMap { it.allSuperMarkers.keys }.toSet()

core/src/test/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/JupyterCodegenTests.kt

@@ -36,7 +36,7 @@ class JupyterCodegenTests : JupyterReplTestCase() {
         @Language("kts")
         val res1 = exec(
             """
-            @DataSchema(isOpen = false)
+            @DataSchema
             data class A(val a: Int)
             """.trimIndent()
         )
@@ -52,6 +52,69 @@ class JupyterCodegenTests : JupyterReplTestCase() {
         (res2 as AnyFrame).should { it.isNotEmpty() }
     }
 
+    @Test
+    fun `Don't inherit from non open class`() {
+        @Language("kts")
+        val res1 = exec(
+            """
+            @DataSchema
+            class A(val a: Int)
+            """.trimIndent()
+        )
+
+        @Language("kts")
+        val res2 = execRaw(
+            """
+            val df = dataFrameOf("a", "b")(1, 2)
+            df
+            """.trimIndent()
+        )
+
+        (res2 as AnyFrame).should { it.isNotEmpty() }
+    }
+
+    @Test
+    fun `Don't inherit from open class`() {
+        @Language("kts")
+        val res1 = exec(
+            """
+            @DataSchema
+            open class A(val a: Int)
+            """.trimIndent()
+        )
+
+        @Language("kts")
+        val res2 = execRaw(
+            """
+            val df = dataFrameOf("a", "b")(1, 2)
+            df
+            """.trimIndent()
+        )
+
+        (res2 as AnyFrame).should { it.isNotEmpty() }
+    }
+
+    @Test
+    fun `Do inherit from open interface`() {
+        @Language("kts")
+        val res1 = exec(
+            """
+            @DataSchema
+            interface A { val a: Int }
+            """.trimIndent()
+        )
+
+        @Language("kts")
+        val res2 = execRaw(
+            """
+            val df = dataFrameOf("a", "b")(1, 2)
+            df
+            """.trimIndent()
+        )
+
+        (res2 as AnyFrame).should { it.isNotEmpty() }
+    }
+
     @Test
     fun `codegen for enumerated frames`() {
         @Language("kts")