Misc fix

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/state/StateDataSource.scala

@@ -28,9 +28,9 @@ import org.apache.spark.sql.{RuntimeConfig, SparkSession}
 import org.apache.spark.sql.catalyst.DataSourceOptions
 import org.apache.spark.sql.connector.catalog.{Table, TableProvider}
 import org.apache.spark.sql.connector.expressions.Transform
-import org.apache.spark.sql.execution.datasources.v2.state.StateSourceOptions.JoinSideValues
+import org.apache.spark.sql.execution.datasources.v2.state.StateSourceOptions.{JoinSideValues, STATE_VAR_NAME}
 import org.apache.spark.sql.execution.datasources.v2.state.StateSourceOptions.JoinSideValues.JoinSideValues
-import org.apache.spark.sql.execution.datasources.v2.state.metadata.StateMetadataPartitionReader
+import org.apache.spark.sql.execution.datasources.v2.state.metadata.{StateMetadataPartitionReader, StateMetadataTableEntry}
 import org.apache.spark.sql.execution.streaming.{CommitLog, OffsetSeqLog, OffsetSeqMetadata}
 import org.apache.spark.sql.execution.streaming.StreamingCheckpointConstants.{DIR_NAME_COMMITS, DIR_NAME_OFFSETS, DIR_NAME_STATE}
 import org.apache.spark.sql.execution.streaming.StreamingSymmetricHashJoinHelper.{LeftSide, RightSide}
@@ -54,6 +54,30 @@ class StateDataSource extends TableProvider with DataSourceRegister {
 
   private lazy val TRANSFORM_WITH_STATE_OPERATOR_SHORT_NAME = "transformWithStateExec"
 
+  private def runStateVarChecks(
+      sourceOptions: StateSourceOptions,
+      stateStoreMetadata: Array[StateMetadataTableEntry]): Unit = {
+    // Perform checks for transformWithState operator in case state variable name is provided
+    require(stateStoreMetadata.size == 1)
+    val opMetadata = stateStoreMetadata.head
+    // if we are trying to query state source with state variable name, then the operator
+    // should be transformWithState
+    if (opMetadata.operatorName != TRANSFORM_WITH_STATE_OPERATOR_SHORT_NAME) {
+      val errorMsg = "Providing state variable names is only supported with the " +
+        s"transformWithState operator. Found operator=${opMetadata.operatorName}. " +
+        s"Please remove this option and re-run the query."
+      throw StateDataSourceErrors.invalidOptionValue(STATE_VAR_NAME, errorMsg)
+    }
+
+    // if the operator is transformWithState, but the operator properties are empty, then
+    // the user has not defined any state variables for the operator
+    val operatorProperties = opMetadata.operatorProperties
+    if (operatorProperties.isEmpty) {
+      throw StateDataSourceErrors.invalidOptionValue(STATE_VAR_NAME,
+        "No state variable names are defined for the transformWithState operator")
+    }
+  }
+
   override def getTable(
       schema: StructType,
       partitioning: Array[Transform],
@@ -71,15 +95,7 @@ class StateDataSource extends TableProvider with DataSourceRegister {
     }
 
     if (sourceOptions.stateVarName.isDefined) {
-      // Perform checks for transformWithState operator in case state variable name is provided
-      allStateStoreMetadata.foreach { entry =>
-        if (entry.operatorName != TRANSFORM_WITH_STATE_OPERATOR_SHORT_NAME) {
-          val errorMsg = "Providing state variable names is only supported with the " +
-            s"transformWithState operator. Found operator=${entry.operatorName}"
-          throw StateDataSourceErrors.invalidOptionValue(sourceOptions.stateVarName.get,
-            errorMsg)
-        }
-      }
+      runStateVarChecks(sourceOptions, stateStoreMetadata)
     }
 
     new StateTable(session, schema, sourceOptions, stateConf, stateStoreMetadata)

sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/v2/state/StateDataSourceReadSuite.scala

@@ -268,6 +268,25 @@ class StateDataSourceNegativeTestSuite extends StateDataSourceTestBase {
           "message" -> s"value should be less than or equal to $endBatchId"))
     }
   }
+
+  test("ERROR: trying to specify state variable name with " +
+    s"non-transformWithState operator") {
+    withTempDir { tempDir =>
+      runDropDuplicatesQuery(tempDir.getAbsolutePath)
+
+      val exc = intercept[StateDataSourceInvalidOptionValue] {
+        spark.read.format("statestore")
+          // trick to bypass getting the last committed batch before validating operator ID
+          .option(StateSourceOptions.BATCH_ID, 0)
+          .option(StateSourceOptions.STATE_VAR_NAME, "test")
+          .load(tempDir.getAbsolutePath)
+      }
+      checkError(exc, "STDS_INVALID_OPTION_VALUE.WITH_MESSAGE", Some("42616"),
+        Map("optionName" -> StateSourceOptions.STATE_VAR_NAME,
+          "message" -> ".*"),
+        matchPVals = true)
+    }
+  }
 }
 
 /**