[New Practice Exercise]: Reverse string (#713)

* Add reverse-string exercise

* Fix json

* Fix files

config.json

@@ -298,6 +298,14 @@
         "difficulty": 1,
         "topics": ["optional_values", "text_formatting"]
       },
+      {
+        "slug": "reverse-string",
+        "name": "Reverse String",
+        "uuid": "f030605e-e971-4153-8927-b4046742fc71",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
+      },
       {
         "slug": "accumulate",
         "name": "Accumulate",

exercises/practice/reverse-string/.docs/instructions.md

@@ -0,0 +1,9 @@
+# Instructions
+
+Your task is to reverse a given string.
+
+Some examples:
+
+- Turn `"stressed"` into `"desserts"`.
+- Turn `"strops"` into `"sports"`.
+- Turn `"racecar"` into `"racecar"`.

exercises/practice/reverse-string/.docs/introduction.md

@@ -0,0 +1,5 @@
+# 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.

exercises/practice/reverse-string/.gitignore

@@ -0,0 +1,4 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj

exercises/practice/reverse-string/.meta/Sources/ReverseString/ReverseStringExample.swift

@@ -0,0 +1,3 @@
+func reverseString(_ input : String) -> String {
+    return String(input.reversed())
+}

exercises/practice/reverse-string/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": ["meatball133"],
+  "files": {
+    "solution": [
+      "Sources/ReverseString/ReverseString.swift"
+    ],
+    "test": [
+      "Tests/ReverseStringTests/ReverseStringTests.swift"
+    ],
+    "example": [
+      ".meta/Sources/ReverseString/ReverseStringExample.swift"
+    ]
+  },
+  "blurb": "Reverse a given string.",
+  "source": "Introductory challenge to reverse an input string",
+  "source_url": "https://medium.freecodecamp.org/how-to-reverse-a-string-in-javascript-in-3-different-ways-75e4763c68cb"
+}

exercises/practice/reverse-string/.meta/template.swift

@@ -0,0 +1,16 @@
+import XCTest
+@testable import {{exercise|camelCase}}
+class {{exercise|camelCase}}Tests: XCTestCase {
+    let runAll = Bool(ProcessInfo.processInfo.environment["RUNALL", default: "false"]) ?? false
+
+    {% for case in cases %}
+    {% if forloop.first -%}
+        func test{{case.description |camelCase }}() {
+    {% else -%}
+        func test{{case.description |camelCase }}() throws {
+        try XCTSkipIf(true && !runAll) // change true to false to run this test
+    {% endif -%}
+        XCTAssertEqual(reverseString("{{case.input.value}}"), "{{case.expected}}")
+    }
+    {% endfor -%}
+}

exercises/practice/reverse-string/.meta/tests.toml

@@ -0,0 +1,28 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[c3b7d806-dced-49ee-8543-933fd1719b1c]
+description = "an empty string"
+
+[01ebf55b-bebb-414e-9dec-06f7bb0bee3c]
+description = "a word"
+
+[0f7c07e4-efd1-4aaa-a07a-90b49ce0b746]
+description = "a capitalized word"
+
+[71854b9c-f200-4469-9f5c-1e8e5eff5614]
+description = "a sentence with punctuation"
+
+[1f8ed2f3-56f3-459b-8f3e-6d8d654a1f6c]
+description = "a palindrome"
+
+[b9e7dec1-c6df-40bd-9fa3-cd7ded010c4c]
+description = "an even-sized word"

exercises/practice/reverse-string/Package.swift

@@ -0,0 +1,21 @@
+// swift-tools-version:5.3
+
+import PackageDescription
+
+let package = Package(
+  name: "ReverseString",
+  products: [
+    .library(
+      name: "ReverseString",
+      targets: ["ReverseString"])
+  ],
+  dependencies: [],
+  targets: [
+    .target(
+      name: "ReverseString",
+      dependencies: []),
+    .testTarget(
+      name: "ReverseStringTests",
+      dependencies: ["ReverseString"]),
+  ]
+)

exercises/practice/reverse-string/Sources/ReverseString/ReverseString.swift

@@ -0,0 +1,3 @@
+func reverseString(_ input : String) -> String {
+    // Write your code for the 'Reverse String' exercise in this file.
+}

exercises/practice/reverse-string/Tests/ReverseStringTests/ReverseStringTests.swift

@@ -0,0 +1,36 @@
+import XCTest
+
+@testable import ReverseString
+
+class ReverseStringTests: XCTestCase {
+  let runAll = Bool(ProcessInfo.processInfo.environment["RUNALL", default: "false"]) ?? false
+
+  func testAnEmptyString() {
+    XCTAssertEqual(reverseString(""), "")
+  }
+
+  func testAWord() throws {
+    try XCTSkipIf(true && !runAll)  // change true to false to run this test
+    XCTAssertEqual(reverseString("robot"), "tobor")
+  }
+
+  func testACapitalizedWord() throws {
+    try XCTSkipIf(true && !runAll)  // change true to false to run this test
+    XCTAssertEqual(reverseString("Ramen"), "nemaR")
+  }
+
+  func testASentenceWithPunctuation() throws {
+    try XCTSkipIf(true && !runAll)  // change true to false to run this test
+    XCTAssertEqual(reverseString("I'm hungry!"), "!yrgnuh m'I")
+  }
+
+  func testAPalindrome() throws {
+    try XCTSkipIf(true && !runAll)  // change true to false to run this test
+    XCTAssertEqual(reverseString("racecar"), "racecar")
+  }
+
+  func testAnEvenSizedWord() throws {
+    try XCTSkipIf(true && !runAll)  // change true to false to run this test
+    XCTAssertEqual(reverseString("drawer"), "reward")
+  }
+}