[Scala] Reverse String

Author: sanderploegsma

scala/build.sbt

@@ -7,7 +7,7 @@ lazy val root = (project in file("."))
     `saddle-points`, `simple-linked-list`, `pythagorean-triplet`, `queen-attack`, `nucleotide-count`, `complex-numbers`,
     `custom-set`, `binary-search`, grains, `linked-list`, `binary-search-tree`, sublist, `largest-series-product`,
     `zebra-puzzle`, raindrops, bowling, strain, `sum-of-multiples`, `protein-translation`, sieve, `rna-transcription`,
-    darts, `high-scores`, `difference-of-squares`, pangram, isogram, anagram, `matching-brackets`)
+    darts, `high-scores`, `difference-of-squares`, pangram, isogram, anagram, `matching-brackets`, `reverse-string`)
 
 lazy val `all-your-base` = project
 lazy val allergies = project
@@ -44,6 +44,7 @@ lazy val `protein-translation` = project
 lazy val `pythagorean-triplet` = project
 lazy val `queen-attack` = project
 lazy val raindrops = project
+lazy val `reverse-string` = project
 lazy val `rna-transcription` = project
 lazy val `robot-name` = project
 lazy val `robot-simulator` = project

scala/reverse-string/HELP.md

@@ -0,0 +1,35 @@
+# Help
+
+## Running the tests
+
+To run the tests, run the command `sbt test` in the exercise's directory.
+See the [tests page](https://exercism.org/docs/tracks/scala/tests) for more information.
+
+## Skipped tests
+
+Initially, only the first test will be enabled.
+This is to encourage you to solve the exercise one step at a time.
+Once you get the first test passing, remove the `pending` keyword from the beginning of the next test and work on getting that test passing.
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit src/main/scala/ReverseString.scala` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Scala track's documentation](https://exercism.org/docs/tracks/scala)
+- The [Scala track's programming category on the forum](https://forum.exercism.org/c/programming/scala)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+Please see the [learning](https://exercism.org/docs/tracks/scala/learning) and [installation](https://exercism.org/docs/tracks/scala/installation) pages if you need any help.

scala/reverse-string/README.md

@@ -0,0 +1,30 @@
+# Reverse String
+
+Welcome to Reverse String on Exercism's Scala Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Introduction
+
+Reversing strings (reading them from right to left, rather than from left to right) is a surprisingly common task in programming.
+
+For example, in bioinformatics, reversing the sequence of DNA or RNA strings is often important for various analyses, such as finding complementary strands or identifying palindromic sequences that have biological significance.
+
+## Instructions
+
+Your task is to reverse a given string.
+
+Some examples:
+
+- Turn `"stressed"` into `"desserts"`.
+- Turn `"strops"` into `"sports"`.
+- Turn `"racecar"` into `"racecar"`.
+
+## Source
+
+### Created by
+
+- @BNAndras
+
+### Based on
+
+Introductory challenge to reverse an input string - https://medium.freecodecamp.org/how-to-reverse-a-string-in-javascript-in-3-different-ways-75e4763c68cb

scala/reverse-string/build.sbt

@@ -0,0 +1,3 @@
+scalaVersion := "2.13.6"
+
+libraryDependencies += "org.scalatest" %% "scalatest" % "3.2.10" % "test"

scala/reverse-string/src/main/scala/ReverseString.scala

@@ -0,0 +1,4 @@
+object ReverseString {
+  def reverse(str: String): String =
+    str.indices.map(i => str.charAt(str.length - i  - 1)).mkString
+}

scala/reverse-string/src/test/scala/ReverseStringTest.scala

@@ -0,0 +1,30 @@
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+
+class ReverseStringTest extends AnyFunSuite with Matchers {
+  
+  test("an empty string") {
+    ReverseString.reverse("") should be ("")
+  }
+
+  test("a word") {
+    ReverseString.reverse("robot") should be ("tobor")
+  }
+
+  test("a capitalized word") {
+    ReverseString.reverse("Ramen") should be ("nemaR")
+  }
+
+  test("a sentence with punctuation") {
+    ReverseString.reverse("I'm hungry!") should be ("!yrgnuh m'I")
+  }
+
+  test("a palindrome") {
+    ReverseString.reverse("racecar") should be ("racecar")
+  }
+
+  test("an even-sized word") {
+    ReverseString.reverse("drawer") should be ("reward")
+  }
+}