maropu commented on a change in pull request #28830: URL: https://github.com/apache/spark/pull/28830#discussion_r439892041
########## File path: sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala ########## @@ -2548,6 +2548,21 @@ class DataFrameSuite extends QueryTest assert(df.schema === new StructType().add(StructField("d", DecimalType(38, 0)))) } } + + test("SPARK-31990: preserves the input order of colNames in dropDuplicates") { + val df = Seq((1, 2, 3, 4, 5), (1, 2, 3, 4, 5)).toDF("c", "e", "d", "a", "b") + val inputColNames = Seq("c", "b", "c", "d", "b", "c", "b") Review comment: @xuanyuanking Do you have a test input seq to reproduce this issue? I checked if this test suite could fail w/o the hot-fix, but it passed... ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org