test: Add unit testing support

CMakeLists.txt

@@ -4,6 +4,9 @@ set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
+set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/vcpkg/scripts/buildsystems/vcpkg.cmake"
+  CACHE STRING "Vcpkg toolchain file")
+
 project(
   ForFun
   LANGUAGES CXX
@@ -63,3 +66,10 @@ add_executable(
   "sonar"
   "test/sonar.cpp"
 )
+
+find_package(Catch2 3 REQUIRED)
+add_executable(
+  tests
+  test/fizzbuzz_test.cpp
+)
+target_link_libraries(tests PRIVATE Catch2::Catch2WithMain)

include/forfun/fizzbuzz.hpp

@@ -6,6 +6,7 @@
 
 /// Problem source:
 /// https://imranontech.com/2007/01/24/using-fizzbuzz-to-find-developers-who-grok-coding/
+/// https://en.wikipedia.org/wiki/Fizz_buzz
 ///
 /// Original problem text:
 /// Write a program that prints the numbers from 1 to 100. But for multiples of

test/fizzbuzz_test.cpp

@@ -0,0 +1,89 @@
+// Copyright (c) Omar Boukli-Hacene. All rights reserved.
+// Distributed under an MIT-style license that can be
+// found in the LICENSE file.
+
+// SPDX-License-Identifier: MIT
+
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/matchers/catch_matchers_string.hpp>
+
+#include "forfun/fizzbuzz.hpp"
+
+TEST_CASE("fizzbuzz") {
+    SECTION("Numbers other than three and five are concatenated as-is") {
+        REQUIRE_THAT(
+            fizzbuzz(1),
+            Catch::Matchers::Equals("1", Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(2),
+            Catch::Matchers::Equals("12", Catch::CaseSensitive::Yes));
+    }
+
+    SECTION("Multiples of three are concatenated as Fizz") {
+        REQUIRE_THAT(
+            fizzbuzz(3),
+            Catch::Matchers::Equals("12Fizz", Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(6),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz", Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(9),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78Fizz", Catch::CaseSensitive::Yes));
+    }
+
+    SECTION("Multiples of five are concatenated as Buzz") {
+        REQUIRE_THAT(
+            fizzbuzz(5),
+            Catch::Matchers::Equals("12Fizz4Buzz", Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(10),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz", Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(20),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz11Fizz1314FizzBuzz1617Fizz19Buzz",
+                Catch::CaseSensitive::Yes));
+    }
+
+    SECTION("Multiples of both three and five are concatenated as FizzBuzz") {
+        REQUIRE_THAT(
+            fizzbuzz(15),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz11Fizz1314FizzBuzz",
+                Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(16),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz11Fizz1314FizzBuzz16",
+                Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(30),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz11Fizz1314FizzBuzz1617Fizz19BuzzFizz2"
+                "223FizzBuzz26Fizz2829FizzBuzz",
+                Catch::CaseSensitive::Yes));
+    }
+
+    SECTION("Prime number input is computed correctly") {
+        REQUIRE_THAT(
+            fizzbuzz(11),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz11", Catch::CaseSensitive::Yes));
+
+        REQUIRE_THAT(
+            fizzbuzz(17),
+            Catch::Matchers::Equals(
+                "12Fizz4BuzzFizz78FizzBuzz11Fizz1314FizzBuzz1617",
+                Catch::CaseSensitive::Yes));
+    }
+}

vcpkg.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": [
+    "catch2"
+  ]
+}