Merge pull request aaronsilinskas#2 from aaronsilinskas/tv-codereview-2

Move Cell to its own file since multiple classes use it. Moved GridTesting to GridFixture and some other naming cleanup.

Author: aaronsilinskas

practice/game-of-life/src/main/scala/Cell.scala

@@ -0,0 +1,12 @@
+
+case class Cell(x: Int, y: Int) {
+  def neighbors: Set[Cell] = {
+    val neighborCells = for {
+      neighborX <- x - 1 to x + 1
+      neighborY <- y - 1 to y + 1
+      if !(neighborX == x && neighborY == y)
+    } yield Cell(neighborX, neighborY)
+
+    neighborCells.toSet
+  }
+}

practice/game-of-life/src/main/scala/Game.scala

@@ -21,9 +21,3 @@ class Game(rules: Rules) {
     new Grid(survivingCells.toSet)
   }
 }
-
-trait Rules {
-  def isLiveCellSurviving(cell: Cell, liveNeighbors: Int): Boolean
-
-  def isDeadCellReviving(cell: Cell, liveNeighbors: Int): Boolean
-}

practice/game-of-life/src/main/scala/Grid.scala

@@ -1,16 +1,4 @@
 
-case class Cell(x: Int, y: Int) {
-  def neighbors: Set[Cell] = {
-    val neighborCells = for {
-      neighborX <- x - 1 to x + 1
-      neighborY <- y - 1 to y + 1
-      if !(neighborX == x && neighborY == y)
-    } yield Cell(neighborX, neighborY)
-
-    neighborCells.toSet
-  }
-}
-
 class Grid(val liveCells: Set[Cell]) {
 
   def isAlive(cell: Cell): Boolean = {

practice/game-of-life/src/main/scala/DefaultRules.scala renamed to practice/game-of-life/src/main/scala/Rules.scala

@@ -1,4 +1,12 @@
 
+
+trait Rules {
+  def isLiveCellSurviving(cell: Cell, liveNeighbors: Int): Boolean
+
+  def isDeadCellReviving(cell: Cell, liveNeighbors: Int): Boolean
+}
+
+
 class DefaultRules extends Rules {
 
   override def isLiveCellSurviving(cell: Cell, liveNeighbors: Int): Boolean = {
@@ -9,5 +17,4 @@ class DefaultRules extends Rules {
     liveNeighbors == 3
   }
 
-}
-
+}

practice/game-of-life/src/test/scala/GameStepSpec.scala

@@ -1,9 +1,9 @@
-import GridTesting._
+
 import org.scalatest.{FeatureSpec, GivenWhenThen, Matchers}
 
 import scala.collection.mutable
 
-class GameStepSpec extends FeatureSpec with Matchers with GivenWhenThen {
+class GameStepSpec extends FeatureSpec with Matchers with GivenWhenThen with GridFixture {
 
   feature("Each game step applies the rules to all applicable cells.") {
 
@@ -65,10 +65,10 @@ class GameStepSpec extends FeatureSpec with Matchers with GivenWhenThen {
       val randomGroupingOfLiveCells = randomNeighborhood(randomCell(), 5)
 
       val grid = new Grid(randomGroupingOfLiveCells)
-      val liveCellNeighborCountsBeforeRules = countLiveNeighbors(grid, randomGroupingOfLiveCells)
+      val liveCellLiveNeighborCountsBeforeRules = countLiveNeighbors(grid, randomGroupingOfLiveCells)
 
       val deadCellsWhereRulesApply = getDeadNeighbors(randomGroupingOfLiveCells)
-      val deadCellNeighborCountsBeforeRules = countLiveNeighbors(grid, deadCellsWhereRulesApply)
+      val deadCellLiveNeighborCountsBeforeRules = countLiveNeighbors(grid, deadCellsWhereRulesApply)
 
       And("a rule that all live cells die and their dead neighbors become alive")
       val rules = new InvertCellsRules with NeighborCountTracking
@@ -78,8 +78,8 @@ class GameStepSpec extends FeatureSpec with Matchers with GivenWhenThen {
       val nextGrid = game.step(grid)
 
       Then("live neighbor counts reflect the original counts and not any cell deaths or births")
-      rules.liveNeighborCounts shouldBe liveCellNeighborCountsBeforeRules
-      rules.deadNeighborCounts shouldBe deadCellNeighborCountsBeforeRules
+      rules.liveCellLiveNeighborCounts shouldBe liveCellLiveNeighborCountsBeforeRules
+      rules.deadCellLiveNeighborCounts shouldBe deadCellLiveNeighborCountsBeforeRules
 
       And("all live cells are now dead and dead neighbors are now alive")
       nextGrid.liveCells.intersect(randomGroupingOfLiveCells) shouldBe empty
@@ -100,16 +100,16 @@ class GameStepSpec extends FeatureSpec with Matchers with GivenWhenThen {
   }
 
   private trait NeighborCountTracking extends Rules {
-    val liveNeighborCounts = mutable.Map[Cell, Int]()
-    val deadNeighborCounts = mutable.Map[Cell, Int]()
+    val liveCellLiveNeighborCounts = mutable.Map[Cell, Int]()
+    val deadCellLiveNeighborCounts = mutable.Map[Cell, Int]()
 
     abstract override def isLiveCellSurviving(cell: Cell, liveNeighbors: Int): Boolean = {
-      liveNeighborCounts += (cell -> liveNeighbors)
+      liveCellLiveNeighborCounts += (cell -> liveNeighbors)
       super.isLiveCellSurviving(cell, liveNeighbors)
     }
 
     abstract override def isDeadCellReviving(cell: Cell, liveNeighbors: Int): Boolean = {
-      deadNeighborCounts += (cell -> liveNeighbors)
+      deadCellLiveNeighborCounts += (cell -> liveNeighbors)
       super.isDeadCellReviving(cell, liveNeighbors)
     }
   }

practice/game-of-life/src/test/scala/GridTesting.scala renamed to practice/game-of-life/src/test/scala/GridFixture.scala

@@ -1,14 +1,14 @@
 import scala.annotation.tailrec
 import scala.util.Random
 
-object GridTesting {
+trait GridFixture {
 
   def randomCell(): Cell = {
     new Cell(Random.nextInt(), Random.nextInt())
   }
 
   @tailrec
-  def randomCells(count: Int = 1000, excluding: Set[Cell] = Set.empty, including: Set[Cell] = Set.empty): Set[Cell] = {
+  final def randomCells(count: Int = 1000, excluding: Set[Cell] = Set.empty, including: Set[Cell] = Set.empty): Set[Cell] = {
     if (count == 0) {
       including
     } else {
@@ -30,12 +30,12 @@ object GridTesting {
     )
   }
 
-  def randomNeighborhood(seed: Cell, recursiveDepth: Int, neighborsToRecurse:Int = 3): Set[Cell] = {
+  def randomNeighborhood(seed: Cell, recursiveDepth: Int, liveNeighborsPerSeed: Int = 3): Set[Cell] = {
     if (recursiveDepth == 0) {
       Set(seed)
     } else {
       val allNeighbors = getNeighborCells(seed)
-      val randomSubsetOfNeighbors = Random.shuffle(allNeighbors).take(neighborsToRecurse)
+      val randomSubsetOfNeighbors = Random.shuffle(allNeighbors).take(liveNeighborsPerSeed)
       randomSubsetOfNeighbors.flatMap { neighbor =>
         randomNeighborhood(neighbor, recursiveDepth - 1)
       }

practice/game-of-life/src/test/scala/GridSpec.scala

@@ -1,9 +1,9 @@
-import GridTesting._
+
 import org.scalatest.{FeatureSpec, GivenWhenThen, Matchers}
 
 import scala.util.Random
 
-class GridSpec extends FeatureSpec with Matchers with GivenWhenThen {
+class GridSpec extends FeatureSpec with Matchers with GivenWhenThen with GridFixture {
 
   feature("A 2D grid of living and dead cells.") {
     scenario("The grid is 32 bits, two dimensional, and holds living and dead cells.") {
@@ -41,7 +41,8 @@ class GridSpec extends FeatureSpec with Matchers with GivenWhenThen {
 
       Then("the correct live neighbor count is given for each cell")
       for (s <- testScenarios) {
-        s.grid.countLiveNeighbors(s.cell) shouldBe s.expectedLiveNeighborCount
+        import s._
+        grid.countLiveNeighbors(cell) shouldBe expectedLiveNeighborCount
       }
     }
 

practice/game-of-life/src/test/scala/RulesSpec.scala

@@ -1,8 +1,7 @@
 
-import GridTesting._
 import org.scalatest._
 
-class RulesSpec extends FeatureSpec with Matchers {
+class RulesSpec extends FeatureSpec with Matchers with GridFixture {
 
   val rules = new DefaultRules()
   val anyCell = randomCell()