[M1] add cargoxx new

tests/CMakeLists.txt

@@ -11,3 +11,4 @@ cargoxx_add_test(util_error)
 cargoxx_add_test(manifest_parse)
 cargoxx_add_test(manifest_write)
 cargoxx_add_test(layout_discovery)
+cargoxx_add_test(cmd_new)

tests/cmd_new.cpp

@@ -0,0 +1,110 @@
+#include <catch2/catch_test_macros.hpp>
+
+import cargoxx.cli;
+import cargoxx.manifest;
+import cargoxx.util;
+import std;
+
+using cargoxx::cli::cmd_new;
+using cargoxx::util::ErrorCode;
+namespace manifest = cargoxx::manifest;
+
+namespace {
+
+auto fresh_dir() -> std::filesystem::path {
+    auto d = std::filesystem::temp_directory_path() /
+             std::format("cargoxx-cmd_new-test-{}", std::random_device{}());
+    std::filesystem::create_directories(d);
+    return d;
+}
+
+auto read_file(const std::filesystem::path& p) -> std::string {
+    std::ifstream in{p};
+    return std::string{std::istreambuf_iterator<char>(in), {}};
+}
+
+} // namespace
+
+TEST_CASE("cmd_new --bin scaffolds a binary project", "[cli][new]") {
+    auto parent = fresh_dir();
+    REQUIRE(cmd_new("hello", false, parent).has_value());
+
+    auto root = parent / "hello";
+    REQUIRE(std::filesystem::exists(root / "Cargoxx.toml"));
+    REQUIRE(std::filesystem::exists(root / "src" / "main.cpp"));
+    REQUIRE_FALSE(std::filesystem::exists(root / "src" / "lib.cppm"));
+    REQUIRE(std::filesystem::exists(root / ".gitignore"));
+
+    auto m = manifest::parse(root / "Cargoxx.toml");
+    REQUIRE(m.has_value());
+    REQUIRE(m->package.name == "hello");
+    REQUIRE(m->package.version == "0.1.0");
+    REQUIRE(m->package.edition == manifest::Edition::Cpp23);
+
+    auto main_src = read_file(root / "src" / "main.cpp");
+    REQUIRE(main_src.find("import std;") != std::string::npos);
+    REQUIRE(main_src.find("\"hello\"") != std::string::npos);
+}
+
+TEST_CASE("cmd_new --lib scaffolds a library project", "[cli][new]") {
+    auto parent = fresh_dir();
+    REQUIRE(cmd_new("widget", true, parent).has_value());
+
+    auto root = parent / "widget";
+    REQUIRE(std::filesystem::exists(root / "src" / "lib.cppm"));
+    REQUIRE_FALSE(std::filesystem::exists(root / "src" / "main.cpp"));
+
+    auto lib_src = read_file(root / "src" / "lib.cppm");
+    REQUIRE(lib_src.find("export module widget;") != std::string::npos);
+    REQUIRE(lib_src.find("export namespace widget") != std::string::npos);
+    REQUIRE(lib_src.find("Hello from widget!") != std::string::npos);
+}
+
+TEST_CASE("cmd_new replaces hyphens with underscores in module name",
+          "[cli][new]") {
+    auto parent = fresh_dir();
+    REQUIRE(cmd_new("my-project", true, parent).has_value());
+
+    auto m = manifest::parse(parent / "my-project" / "Cargoxx.toml");
+    REQUIRE(m->package.name == "my-project");
+
+    auto lib_src = read_file(parent / "my-project" / "src" / "lib.cppm");
+    REQUIRE(lib_src.find("export module my_project;") != std::string::npos);
+    REQUIRE(lib_src.find("Hello from my-project!") != std::string::npos);
+}
+
+TEST_CASE("cmd_new fails when target directory exists", "[cli][new]") {
+    auto parent = fresh_dir();
+    std::filesystem::create_directories(parent / "exists");
+    auto r = cmd_new("exists", false, parent);
+    REQUIRE_FALSE(r.has_value());
+    REQUIRE(r.error().code == ErrorCode::Internal);
+}
+
+TEST_CASE("cmd_new rejects an empty name", "[cli][new]") {
+    auto parent = fresh_dir();
+    auto r = cmd_new("", false, parent);
+    REQUIRE_FALSE(r.has_value());
+    REQUIRE(r.error().code == ErrorCode::LayoutInvalidName);
+}
+
+TEST_CASE("cmd_new rejects a name starting with a digit", "[cli][new]") {
+    auto parent = fresh_dir();
+    auto r = cmd_new("1bad", false, parent);
+    REQUIRE_FALSE(r.has_value());
+    REQUIRE(r.error().code == ErrorCode::LayoutInvalidName);
+}
+
+TEST_CASE("cmd_new rejects a name with a space", "[cli][new]") {
+    auto parent = fresh_dir();
+    auto r = cmd_new("foo bar", false, parent);
+    REQUIRE_FALSE(r.has_value());
+    REQUIRE(r.error().code == ErrorCode::LayoutInvalidName);
+}
+
+TEST_CASE("cmd_new writes a minimal .gitignore", "[cli][new]") {
+    auto parent = fresh_dir();
+    REQUIRE(cmd_new("foo", false, parent).has_value());
+    auto content = read_file(parent / "foo" / ".gitignore");
+    REQUIRE(content.find("/build/") != std::string::npos);
+}