added test for Issue #1222

Author: Jolanrensen

dataframe-jupyter/src/test/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/CodeGenerationTests.kt

@@ -70,4 +70,24 @@ class CodeGenerationTests : DataFrameJupyterTest() {
         df1.leaf.c
         """.checkCompilation()
     }
+
+    // Issue #1222
+    @Test
+    fun `do not reuse marker with non-matching sub-schema`() {
+        @Language("kt")
+        val _1 = """
+            val df1 = dataFrameOf("group" to columnOf("a" to columnOf(1, null, 3)))
+            val df2 = dataFrameOf("group" to columnOf("a" to columnOf(1, 2, 3)))
+            df1.group.a
+            df2.group.a
+            """.checkCompilation()
+
+        @Language("kt")
+        val _2 = """
+            val df1 = dataFrameOf("group" to columnOf("a" to columnOf(1, 2, 3)))
+            val df2 = dataFrameOf("group" to columnOf("a" to columnOf(1, null, 3)))
+            df1.group.a
+            df2.group.a
+            """.checkCompilation()
+    }
 }