test("first/last with ignore null") {
    val data = Range(0, 3).flatMap(n => Seq((n, 1), (n, 2))).toDF("a", "b")
    withTempDir { dir =>
      val filename = s"${dir.getAbsolutePath}/first_last_ignore_null.parquet"
      data.repartition(2).write.parquet(filename)
      withSQLConf(CometConf.COMET_BATCH_SIZE.key -> "1") {
        spark.read.parquet(filename).createOrReplaceTempView("t1")
        for (expr <- Seq("first", "last")) {
          // deterministic query that should return one non-null value per group
          val df = spark.sql(
            s"SELECT a, $expr(IF(b==1,null,b)) IGNORE NULLS FROM t1 GROUP BY a ORDER BY a")
          checkSparkAnswerAndOperator(df)
        }
      }
    }
  }