feat: replace sample function to git_clone function

Signed-off-by: Alfi Maulana <alfi.maulana.f@gmail.com>

CMakeLists.txt

@@ -22,7 +22,7 @@ if(MY_PROJECT_ENABLE_TESTS)
   enable_testing()
 
   find_package(Assertion 1.0.0 REQUIRED)
-  assertion_add_test(test/mkdir_recursive.cmake)
+  assertion_add_test(test/git_clone.cmake)
 endif()
 
 if(MY_PROJECT_ENABLE_INSTALL)

cmake/MyProject.cmake

@@ -1,3 +1,15 @@
-function(mkdir_recursive DIR_PATH)
-  file(MAKE_DIRECTORY "${DIR_PATH}")
+# Clone a Git repository to a specified directory.
+#
+# git_clone(<url> <dir>)
+#
+# This function clones a Git repository from the `<url>` and saves it to the
+# `<dir>` directory. It outputs a fatal error message if the operation fails.
+function(git_clone URL DIR)
+  execute_process(
+    COMMAND git clone "${URL}" "${DIR}"
+    ERROR_VARIABLE ERR
+    RESULT_VARIABLE RES)
+  if(NOT RES EQUAL 0)
+    message(FATAL_ERROR "Failed to clone '${URL}': ${ERR}")
+  endif()
 endfunction()

test/git_clone.cmake

@@ -0,0 +1,20 @@
+find_package(MyProject REQUIRED PATHS ${CMAKE_CURRENT_LIST_DIR}/../cmake)
+
+section("it should clone a Git repository")
+  file(REMOVE_RECURSE repo)
+
+  git_clone(https://github.com/threeal/cmake-starter repo)
+
+  assert(EXISTS repo)
+  assert_execute_process(git -C repo rev-parse --is-inside-work-tree)
+endsection()
+
+section("it should fail to clone an invalid Git repository")
+  file(REMOVE_RECURSE repo)
+
+  assert_fatal_error(
+    CALL git_clone https://github.com repo
+    MESSAGE "Failed to clone 'https://github.com'")
+
+  assert(NOT EXISTS repo)
+endsection()