Fix for 409: assert on mask target must have NoData defined

Signed-off-by: Jason T. Brown <[email protected]>

Author: vpipkt

core/src/main/scala/org/locationtech/rasterframes/expressions/transformers/Mask.scala

@@ -23,7 +23,7 @@ package org.locationtech.rasterframes.expressions.transformers
 
 import com.typesafe.scalalogging.Logger
 import geotrellis.raster
-import geotrellis.raster.Tile
+import geotrellis.raster.{CellType, NoNoData, Tile}
 import geotrellis.raster.mapalgebra.local.{Undefined, InverseMask ⇒ gtInverseMask, Mask ⇒ gtMask}
 import org.apache.spark.sql.catalyst.analysis.TypeCheckResult
 import org.apache.spark.sql.catalyst.analysis.TypeCheckResult.{TypeCheckFailure, TypeCheckSuccess}
@@ -73,6 +73,15 @@ abstract class Mask(val left: Expression, val middle: Expression, val right: Exp
   override protected def nullSafeEval(targetInput: Any, maskInput: Any, maskValueInput: Any): Any = {
     implicit val tileSer = TileUDT.tileSerializer
     val (targetTile, targetCtx) = tileExtractor(targetExp.dataType)(row(targetInput))
+
+    // Which of these is preferable? companion object Seq contains or pattern match on trait?
+//    assert(!CellType.noNoDataCellTypes.contains(targetTile.cellType), maskErrorStr)
+    targetTile.cellType match {
+      case _: NoNoData ⇒ assert(false,
+        s"Input data expression ${left.prettyName} must have a CellType with NoData defined in order to perform a masking operation. Found CellType ${targetTile.cellType.toString()}.")
+      case _ ⇒
+    }
+
     val (maskTile, maskCtx) = tileExtractor(maskExp.dataType)(row(maskInput))
 
     if (targetCtx.isEmpty && maskCtx.isDefined)