TypedColumn#year and LocalDateTime generator (#228)

* added year function
* changed Column#year type to Option[Int]
* cleanup
* Formatting NonAggregateFunctionsTests
* fix merge conflicts
* clean up after merge
* removed curly braces from `year` function

dataset/src/main/scala/frameless/functions/NonAggregateFunctions.scala

@@ -1,8 +1,7 @@
 package frameless
 package functions
 
-import org.apache.spark.sql.Column
-import org.apache.spark.sql.{functions => untyped}
+import org.apache.spark.sql.{Column, functions => untyped}
 
 import scala.util.matching.Regex
 
@@ -318,4 +317,14 @@ trait NonAggregateFunctions {
     */
   def upper[T](str: AbstractTypedColumn[T, String]): str.ThisType[T, String] =
     str.typed(untyped.upper(str.untyped))
-}
+
+  /**
+    * Non-Aggregate function: Extracts the year as an integer from a given date/timestamp/string.
+    *
+    * Differs from `Column#year` by wrapping it's result into an `Option`.
+    *
+    * apache/spark
+    */
+  def year[T](str: AbstractTypedColumn[T, String]): str.ThisType[T, Option[Int]] =
+    str.typed[Option[Int]](untyped.year(str.untyped))
+}

dataset/src/test/scala/frameless/functions/NonAggregateFunctionsTests.scala

@@ -5,9 +5,9 @@ import java.io.File
 
 import frameless.functions.nonAggregate._
 import org.apache.commons.io.FileUtils
-import org.apache.spark.sql.{Encoder, SaveMode, functions => untyped}
-import org.scalacheck.Gen
+import org.apache.spark.sql.{Encoder, Row, SaveMode, functions => untyped}
 import org.scalacheck.Prop._
+import org.scalacheck.{Gen, Prop}
 
 class NonAggregateFunctionsTests extends TypedDatasetSuite {
   val testTempFiles = "target/testoutput"
@@ -33,7 +33,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
           .map(_.getAs[B](0))
           .collect().toList
 
-
         val typedDS = TypedDataset.create(values)
         val col = typedDS('a)
         val res = typedDS
@@ -98,7 +97,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
         .map(DoubleBehaviourUtils.nanNullHandler)
         .collect().toList
 
-
       val typedDS = TypedDataset.create(values)
       val res = typedDS
         .select(acos(typedDS('a)))
@@ -119,7 +117,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
     check(forAll(prop[Double] _))
   }
 
-
    /*
     * Currently not all Collection types play nice with the Encoders.
     * This test needs to be readressed and Set readded to the Collection Typeclass once these issues are resolved.
@@ -174,7 +171,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
         .map(_.getAs[Boolean](0))
         .collect().toList
 
-
       val typedDS = TypedDataset.create(List(X1(values)))
       val res = typedDS
         .select(arrayContains(typedDS('a), contained))
@@ -185,7 +181,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
       res ?= resCompare
     }
 
-
     check(
       forAll(
         Gen.listOfN(listLength, Gen.choose(0,100)),
@@ -286,7 +281,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
       res ?= resCompare
     }
 
-
     check(forAll(prop[Int] _))
     check(forAll(prop[Long] _))
     check(forAll(prop[Short] _))
@@ -375,7 +369,6 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
       (res ?= resCompare).&&(aggrTyped ?= aggrSpark)
     }
 
-
     check(forAll(prop[Int] _))
     check(forAll(prop[Long] _))
     check(forAll(prop[Short] _))
@@ -660,9 +653,8 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
 
   test("concat for TypedAggregate") {
     val spark = session
-    import spark.implicits._
-
     import frameless.functions.aggregate._
+    import spark.implicits._
     val pairs = for {
       y <- Gen.alphaStr
       x <- Gen.nonEmptyListOf(X2(y, y))
@@ -708,9 +700,8 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
 
   test("concat_ws for TypedAggregate") {
     val spark = session
-    import spark.implicits._
-
     import frameless.functions.aggregate._
+    import spark.implicits._
     val pairs = for {
       y <- Gen.alphaStr
       x <- Gen.listOfN(10, X2(y, y))
@@ -1037,4 +1028,35 @@ class NonAggregateFunctionsTests extends TypedDatasetSuite {
     // This fails due to issue #239
     //check(forAll(prop[Option[Vector[Boolean]], Long] _))
   }
-}
+
+  test("year") {
+    val spark = session
+    import spark.implicits._
+
+    val nullHandler: Row => Option[Int] = _.get(0) match {
+      case i: Int => Some(i)
+      case _ => None
+    }
+
+    def prop(data: List[X1[String]])(implicit E: Encoder[Option[Int]]): Prop = {
+        val ds = TypedDataset.create(data)
+
+        val sparkResult = ds.toDF()
+          .select(untyped.year($"a"))
+          .map(nullHandler)
+          .collect()
+          .toList
+
+        val typed = ds
+          .select(year(ds[String]('a)))
+          .collect()
+          .run()
+          .toList
+
+        typed ?= sparkResult
+      }
+
+    check(forAll(dateTimeStringGen)(data => prop(data.map(X1.apply))))
+    check(forAll(prop _))
+  }
+}

dataset/src/test/scala/frameless/package.scala

@@ -1,3 +1,6 @@
+import java.time.format.DateTimeFormatter
+import java.time.{LocalDateTime => JavaLocalDateTime}
+
 import org.scalacheck.{Arbitrary, Gen}
 
 package object frameless {
@@ -39,5 +42,24 @@ package object frameless {
     } yield new UdtEncodedClass(int, doubles.toArray)
   }
 
+  val dateTimeFormatter: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm")
+
+  implicit val localDateArb: Arbitrary[JavaLocalDateTime] = Arbitrary {
+    for {
+      year <- Gen.chooseNum(1900, 2027)
+      month <- Gen.chooseNum(1, 12)
+      dayOfMonth <- Gen.chooseNum(1, 28)
+      hour <- Gen.chooseNum(1, 23)
+      minute <- Gen.chooseNum(1, 59)
+    } yield JavaLocalDateTime.of(year, month, dayOfMonth, hour, minute)
+  }
+
+  /** LocalDateTime String Generator to test time related Spark functions */
+  val dateTimeStringGen: Gen[List[String]] =
+    for {
+      listOfDates <- Gen.listOf(localDateArb.arbitrary)
+      localDate <- listOfDates
+    } yield localDate.format(dateTimeFormatter)
+
   val TEST_OUTPUT_DIR = "target/test-output"
 }