Issue 16 - Add scalacheck datetime

build.sbt

@@ -11,11 +11,11 @@ lazy val scalacheck = (project in file("."))
     Resolver.sonatypeRepo("releases")
   ),
   libraryDependencies ++= Seq(
-    "org.scalatest" %% "scalatest" % "2.2.4",
-    "org.scala-exercises" %% "exercise-compiler" % version.value,
-    "org.scala-exercises" %% "definitions" % version.value,
-    "org.scalacheck" %% "scalacheck" % "1.12.5",
-    "com.github.alexarchambault" %% "scalacheck-shapeless_1.12" % "0.3.1",
+    "org.scalatest" %% "scalatest" % "3.0.1" exclude("org.scalacheck", "scalacheck"),
+    "org.scala-exercises" %% "exercise-compiler" % version.value excludeAll ExclusionRule("com.github.alexarchambault"),
+    "org.scala-exercises" %% "definitions" % version.value excludeAll ExclusionRule("com.github.alexarchambault"),
+    "com.fortysevendeg" %% "scalacheck-datetime" % "0.2.0",
+    "com.github.alexarchambault" %% "scalacheck-shapeless_1.13" % "1.1.3",
     compilerPlugin("org.spire-math" %% "kind-projector" % "0.9.0")
   )
 )

src/main/scala/scalachecklib/ArbitrarySection.scala

@@ -3,7 +3,7 @@ package scalachecklib
 import org.scalatest.Matchers
 import org.scalatest.prop.Checkers
 
-/** ==The `arbitrary` Generator
+/** ==The `arbitrary` Generator==
   *
   * There is a special generator, `org.scalacheck.Arbitrary.arbitrary`, which generates arbitrary values of any
   * supported type.

src/main/scala/scalachecklib/PropertiesSection.scala

@@ -185,7 +185,7 @@ object PropertiesSection extends Checkers with Matchers with org.scalaexercises.
     *
     */
     def groupingProperties(res0: Int, res1: Int, res2: Int) = {
-      import org.scalacheck.Properties
+      import org.scalacheck.{Prop, Properties}
 
       class ZeroSpecification extends Properties("Zero") {
 
@@ -199,6 +199,6 @@ object PropertiesSection extends Checkers with Matchers with org.scalaexercises.
 
       }
 
-      check(new ZeroSpecification)
+      check(Prop.all(new ZeroSpecification().properties.map(_._2): _*))
     }
 }

src/main/scala/scalachecklib/ScalacheckDatetimeSection.scala

@@ -0,0 +1,153 @@
+package scalachecklib
+
+import org.scalatest.Matchers
+import org.scalatest.prop.Checkers
+
+/** scalacheck-datetime is a library for helping use datetime libraries with ScalaCheck
+  *
+  * The motivation behind this library is to provide a simple, easy way to provide generated date and time instances
+  * that are useful to your own domain.
+  *
+  * For SBT, you can add the dependency to your project’s build file:
+  *
+  * {{{
+  * resolvers += Resolver.sonatypeRepo("releases")
+  *
+  * "com.fortysevendeg" %% "scalacheck-datetime" % "0.2.0" % "test"
+  * }}}
+  *
+  * Please, visit the [[https://47deg.github.io/scalacheck-datetime homepage]] for more information
+  *
+  * @param name scalacheck-datetime
+  */
+object ScalacheckDatetimeSection extends Checkers with Matchers with org.scalaexercises.definitions.Section {
+
+  /** ==Usage==
+    *
+    * To arbitrarily generate dates and times, you need to have the `Arbitrary` in scope for your date/time class.
+    * Assuming Joda Time:
+    */
+  def usage(res0: Boolean) = {
+
+    import com.fortysevendeg.scalacheck.datetime.joda.ArbitraryJoda._
+    import org.joda.time.DateTime
+    import org.scalacheck.Prop.forAll
+
+    check {
+      forAll { dt: DateTime =>
+        (dt.getDayOfMonth >= 1 && dt.getDayOfMonth <= 31) == res0
+      }
+    }
+  }
+
+  /** ==A note on imports==
+    *
+    * For all of the examples given in this document, you can substitute `jdk8` for `joda` and vice-versa,
+    * depending on which library you would like to generate instances for.
+    *
+    * ==Implementation==
+    *
+    * The infrastructure behind the generation of date/time instances for any given date/time library,
+    * which may take ranges into account, is done using a fairly simple typeclass, which has the type signature
+    * `ScalaCheckDateTimeInfra[D, R]`. That is to say, as long as there is an implicit `ScalaCheckDateTimeInfra`
+    * instance in scope for a given date/time type `D` (such as Joda’s `DateTime`) and a range type `R`
+    * (such as Joda’s `Period`), then the code will compile and be able to provide generated date/time instances.
+    *
+    * As stated, currently there are two instances, `ScalaCheckDateTimeInfra[DateTime, Period]` for Joda Time and
+    * `ScalaCheckDateTimeInfra[ZonedDateTime, Duration]` for Java SE 8’s Date and Time.
+    *
+    * ==Granularity==
+    *
+    * If you wish to restrict the precision of the generated instances, this library refers to that as <i>granularity</i>.
+    *
+    * You can constrain the granularity to:
+    *
+    * <ul>
+    *  <li>Seconds</li>
+    *  <li>Minutes</li>
+    *  <li>Hours</li>
+    *  <li>Days</li>
+    *  <li>Years</li>
+    * </ul>
+    *
+    *  When a value is constrained, the time fields are set to zero, and the rest to the first day of the month,
+    *  or day of the year. For example, if you constrain a field to be years, the generated instance will be midnight
+    *  exactly, on the first day of January.
+    *
+    *  To constrain a generated type, you simply need to provide an import for the typeclass for your date/time and
+    *  range, and also an import for the granularity. As an example, this time using Java SE 8's `java.time` package:
+    */
+  def granularity(res0: Int, res1: Int, res2: Int, res3: Int, res4: Int) = {
+
+    import java.time._
+    import com.fortysevendeg.scalacheck.datetime.jdk8.ArbitraryJdk8._
+    import com.fortysevendeg.scalacheck.datetime.jdk8.granularity.years
+    import org.scalacheck.Prop.forAll
+
+    check {
+      forAll { zdt: ZonedDateTime =>
+        zdt.getMonth == Month.JANUARY
+        (zdt.getDayOfMonth == res0) &&
+          (zdt.getHour == res1) &&
+          (zdt.getMinute == res2) &&
+          (zdt.getSecond == res3) &&
+          (zdt.getNano == res4)
+      }
+    }
+
+  }
+
+  /** ==Creating Ranges==
+    *
+    * You can generate date/time instances only within a certain range, using the `genDateTimeWithinRange` in the
+    * `GenDateTime` class. The function takes two parameters, the date/time instances as a base from which to generate
+    * new date/time instances, and a range for the generated instances.
+    *
+    * If the range is positive, it will be in the future from the base date/time, negative in the past.
+    *
+    * Showing this usage with Joda Time:
+    */
+  def ranges(res0: Int) = {
+
+    import org.joda.time._
+    import com.fortysevendeg.scalacheck.datetime.instances.joda._
+    import com.fortysevendeg.scalacheck.datetime.GenDateTime.genDateTimeWithinRange
+    import org.scalacheck.Prop.forAll
+
+    val from = new DateTime(2016, 1, 1, 0, 0)
+    val range = Period.years(1)
+
+    check {
+      forAll(genDateTimeWithinRange(from, range)) { dt =>
+        dt.getYear == res0
+      }
+    }
+  }
+
+  /** ==Using Granularity and Ranges Together==
+    *
+    * As you would expect, it is possible to use the granularity and range concepts together.
+    * This example should not show anything surprising by now:
+    */
+  def granularityAndRanges(res0: Int, res1: Int, res2: Int, res3: Int, res4: Int) = {
+
+    import org.joda.time._
+    import com.fortysevendeg.scalacheck.datetime.instances.joda._
+    import com.fortysevendeg.scalacheck.datetime.GenDateTime.genDateTimeWithinRange
+    import com.fortysevendeg.scalacheck.datetime.joda.granularity.days
+    import org.scalacheck.Prop.forAll
+
+    val from = new DateTime(2016, 1, 1, 0, 0)
+    val range = Period.years(1)
+
+    check {
+      forAll(genDateTimeWithinRange(from, range)) { dt =>
+        (dt.getYear == res0) &&
+          (dt.getHourOfDay == res1) &&
+          (dt.getMinuteOfHour == res2) &&
+          (dt.getSecondOfMinute == res3) &&
+          (dt.getMillisOfSecond == res4)
+      }
+    }
+  }
+}

src/main/scala/scalachecklib/ScalacheckLibrary.scala

@@ -12,7 +12,8 @@ object ScalacheckLibrary extends org.scalaexercises.definitions.Library {
 
   override def sections = List(
     PropertiesSection,
-    GeneratorsSection
+    GeneratorsSection,
+    ScalacheckDatetimeSection
   )
 
   override def logoPath = "scalacheck"

src/test/scala/scalachecklib/ArbitrarySpec.scala

@@ -1,14 +1,13 @@
 package scalachecklib
 
 import org.scalacheck.Shapeless._
-import org.scalaexercises.Test
-import org.scalatest.Spec
+import org.scalatest.FunSuite
 import org.scalatest.prop.Checkers
 import shapeless.HNil
 
-class ArbitrarySpec extends Spec with Checkers {
+class ArbitrarySpec extends FunSuite with Checkers {
 
-  def `implicit arbitrary char` = {
+  test("implicit arbitrary char") {
 
     check(
       Test.testSuccess(
@@ -18,7 +17,7 @@ class ArbitrarySpec extends Spec with Checkers {
     )
   }
 
-  def `implicit arbitrary case class` = {
+  test("implicit arbitrary case class") {
 
     check(
       Test.testSuccess(
@@ -28,7 +27,7 @@ class ArbitrarySpec extends Spec with Checkers {
     )
   }
 
-  def `arbitrary on gen` = {
+  test("arbitrary on gen") {
 
     check(
       Test.testSuccess(

src/test/scala/scalachecklib/GeneratorsSpec.scala

@@ -1,14 +1,13 @@
 package scalachecklib
 
 import org.scalacheck.Shapeless._
-import org.scalaexercises.Test
-import org.scalatest.Spec
+import org.scalatest.FunSuite
 import org.scalatest.prop.Checkers
 import shapeless.HNil
 
-class GeneratorsSpec extends Spec with Checkers {
+class GeneratorsSpec extends FunSuite with Checkers {
 
-  def `for-comprehension generator` = {
+  test("for-comprehension generator") {
 
     check(
       Test.testSuccess(
@@ -19,7 +18,7 @@ class GeneratorsSpec extends Spec with Checkers {
 
   }
 
-  def `oneOf method` = {
+  test("oneOf method") {
 
     check(
       Test.testSuccess(
@@ -30,7 +29,7 @@ class GeneratorsSpec extends Spec with Checkers {
 
   }
 
-  def `alphaChar, posNum and listOfN` = {
+  test("alphaChar, posNum and listOfN") {
 
     check(
       Test.testSuccess(
@@ -41,7 +40,7 @@ class GeneratorsSpec extends Spec with Checkers {
 
   }
 
-  def `suchThat condition` = {
+  test("suchThat condition") {
 
     check(
       Test.testSuccess(
@@ -52,7 +51,7 @@ class GeneratorsSpec extends Spec with Checkers {
 
   }
 
-  def `case class generator` = {
+  test("case class generator") {
 
     check(
       Test.testSuccess(
@@ -63,7 +62,7 @@ class GeneratorsSpec extends Spec with Checkers {
 
   }
 
-  def `sized generator` = {
+  test("sized generator") {
 
     check(
       Test.testSuccess(
@@ -74,7 +73,7 @@ class GeneratorsSpec extends Spec with Checkers {
 
   }
 
-  def `list container` = {
+  test("list container") {
 
     check(
       Test.testSuccess(

src/test/scala/scalachecklib/PropertiesSpec.scala

@@ -1,15 +1,13 @@
 package scalachecklib
 
 import org.scalacheck.Shapeless._
-import org.scalaexercises.Test
-import org.scalatest.Spec
+import org.scalatest.FunSuite
 import org.scalatest.prop.Checkers
 import shapeless.HNil
 
+class PropertiesSpec extends FunSuite with Checkers {
 
-class PropertiesSpec extends Spec with Checkers {
-
-  def `always ends with the second string` = {
+  test("always ends with the second string") {
 
     check(
       Test.testSuccess(
@@ -19,7 +17,7 @@ class PropertiesSpec extends Spec with Checkers {
     )
   }
 
-  def `all numbers are generated between the desired interval` = {
+  test("all numbers are generated between the desired interval") {
 
     check(
       Test.testSuccess(
@@ -29,7 +27,7 @@ class PropertiesSpec extends Spec with Checkers {
     )
   }
 
-  def `all generated numbers are even` = {
+  test("all generated numbers are even") {
 
     check(
       Test.testSuccess(
@@ -39,7 +37,7 @@ class PropertiesSpec extends Spec with Checkers {
     )
   }
 
-  def `only the second condition is true` = {
+  test("only the second condition is true") {
 
     check(
       Test.testSuccess(
@@ -49,7 +47,7 @@ class PropertiesSpec extends Spec with Checkers {
     )
   }
 
-  def `the zero specification only works for 0` = {
+  test("the zero specification only works for 0") {
 
     check(
       Test.testSuccess(