From ff53f828d439442f5586cb8ec0723029a00e19da Mon Sep 17 00:00:00 2001
From: Ric Emery <ric.emery@gmail.com>
Date: Mon, 2 Oct 2017 14:53:36 -0700
Subject: [PATCH] Create SaddlePointsTestGenerator. Update SaddlePointsTest.
 Refs #370, #331

---
 exercises/saddle-points/example.scala         | 18 ++++++----
 .../src/test/scala/SaddlePointsTest.scala     | 35 +++++++++++--------
 .../scala/SaddlePointsTestGenerator.scala     | 35 +++++++++++++++++++
 3 files changed, 67 insertions(+), 21 deletions(-)
 create mode 100644 testgen/src/main/scala/SaddlePointsTestGenerator.scala

diff --git a/exercises/saddle-points/example.scala b/exercises/saddle-points/example.scala
index 3e90acbd..cf9bbdef 100644
--- a/exercises/saddle-points/example.scala
+++ b/exercises/saddle-points/example.scala
@@ -1,12 +1,16 @@
 case class Matrix(values: List[List[Int]]) {
   lazy val saddlePoints: Set[(Int, Int)] = {
-    val rowMaxes = values.map(_.max).toVector
     val columns = values.transpose
-    val colMins = columns.map(_.min).toVector
-    (for {
-      i <- 0 until values.length
-      j <- 0 until columns.length
-      if rowMaxes(i) == colMins(j)
-    } yield (i, j)).toSet
+    if (values.isEmpty || columns.isEmpty) {
+      Set()
+    } else {
+      val rowMaxes = values.map(_.max).toVector
+      val colMins = columns.map(_.min).toVector
+      (for {
+        i <- values.indices
+        j <- columns.indices
+        if rowMaxes(i) == colMins(j)
+      } yield (i, j)).toSet
+    }
   }
 }
diff --git a/exercises/saddle-points/src/test/scala/SaddlePointsTest.scala b/exercises/saddle-points/src/test/scala/SaddlePointsTest.scala
index 48b07e60..237e7ec3 100644
--- a/exercises/saddle-points/src/test/scala/SaddlePointsTest.scala
+++ b/exercises/saddle-points/src/test/scala/SaddlePointsTest.scala
@@ -1,26 +1,33 @@
-import org.scalatest.{Matchers, FlatSpec}
+import org.scalatest.{Matchers, FunSuite}
 
-class SaddlePointsSpecs extends FlatSpec with Matchers {
-  it should "handle one saddle" in {
-    val points = Matrix(List(List(9, 8, 7), List(5, 3, 2), List(6, 6, 7))).saddlePoints
-    points should be (Set((1, 0)))
+/** @version 1.0.0 */
+class SaddlePointsTest extends FunSuite with Matchers {
+
+  test("Can identify single saddle point") {
+    Matrix(List(List(9, 8, 7), List(5, 3, 2), List(6, 6, 7))).saddlePoints should be(
+      Set((1, 0)))
+  }
+
+  test("Can identify that empty matrix has no saddle points") {
+    pending
+    Matrix(List(List())).saddlePoints should be(Set())
   }
 
-  it should "handle multiple saddles" in {
+  test("Can identify lack of saddle points when there are none") {
     pending
-    val points = Matrix(List(List(5, 3, 5, 4), List(6, 4, 7, 3), List(5, 1, 5, 3))).saddlePoints
-    points should be (Set((0, 0), (0, 2), (2, 0), (2, 2)))
+    Matrix(List(List(1, 2, 3), List(3, 1, 2), List(2, 3, 1))).saddlePoints should be(
+      Set())
   }
 
-  it should "handle no saddles" in {
+  test("Can identify multiple saddle points") {
     pending
-    val points = Matrix(List(List(2, 1), List(1, 2))).saddlePoints
-    points should be (Set())
+    Matrix(List(List(4, 5, 4), List(3, 5, 5), List(1, 5, 4))).saddlePoints should be(
+      Set((0, 1), (1, 1), (2, 1)))
   }
 
-  it should "handle empty matrix" in {
+  test("Can identify saddle point in bottom right corner") {
     pending
-    val points = Matrix(List()).saddlePoints
-    points should be (Set())
+    Matrix(List(List(8, 7, 9), List(6, 7, 6), List(3, 2, 5))).saddlePoints should be(
+      Set((2, 2)))
   }
 }
diff --git a/testgen/src/main/scala/SaddlePointsTestGenerator.scala b/testgen/src/main/scala/SaddlePointsTestGenerator.scala
new file mode 100644
index 00000000..c236c858
--- /dev/null
+++ b/testgen/src/main/scala/SaddlePointsTestGenerator.scala
@@ -0,0 +1,35 @@
+import java.io.File
+
+import testgen.TestSuiteBuilder._
+import testgen._
+
+object SaddlePointsTestGenerator {
+  def toString(expected: CanonicalDataParser.Expected): String = {
+    expected match {
+      case Right(xs: List[Map[String, Int]]) =>
+        val tuples = xs.map(m => s"(${m("row")}, ${m("column")})").mkString(", ")
+        s"""Set($tuples)"""
+      case _ => throw new IllegalArgumentException
+    }
+  }
+
+  def fromLabeledTest(argNames: String*): ToTestCaseData =
+    withLabeledTest { sut =>
+      labeledTest =>
+        val args = sutArgs(labeledTest.result, argNames: _*)
+        val property = labeledTest.property
+        val sutCall =
+          s"""Matrix($args).$property"""
+        val expected = toString(labeledTest.expected)
+        TestCaseData(labeledTest.description, sutCall, expected)
+    }
+
+  def main(args: Array[String]): Unit = {
+    val file = new File("src/main/resources/saddle-points.json")
+
+    val code = TestSuiteBuilder.build(file, fromLabeledTest("input"))
+    println(s"-------------")
+    println(code)
+    println(s"-------------")
+  }
+}