Dynamically modified on fly

If input data structure is complex, and only several fields take part in transformation, presaved data can be read, and fields modified on fly.

test("Mass When weight specified Then weights sum") {
  val expected = 85
  val input = getBulkData.withColumn("weight", lit(85))
  repository.mass(input) shouldBe expected
}

test("Mass When weight is null Then NPE") {
  val input = getBulkData.withColumn("weight", lit(null).cast(DataTypes.IntegerType))
  intercept[RuntimeException] {
    repository.mass(input)
  }

}

private def getBulkData = spark.read.option("header", "true").csv(getTestDataFolder)

Example: DynamicallyModifiedOnFlySpec.scala