Improve new project library workflow

Author: GaspardKirira

src/commands/NewCommand.cpp

@@ -349,8 +349,8 @@ namespace vix::commands::NewCommand
         << "  • Generates a ready-to-run Vix project\n"
         << "  • Sets up CMake, source structure, and config files\n"
         << "  • Creates a vix.json manifest\n"
-        << "  • For apps, includes default tasks and an empty deps list\n"
-        << "  • For libraries, includes package metadata and an empty deps list\n"
+        << "  • For apps, creates an executable target matching the project name\n"
+        << "  • For libraries, creates a header-only CMake interface target\n"
         << "  • Applies the selected template (app or library)\n\n"
 
         << "Options\n"
@@ -359,6 +359,17 @@ namespace vix::commands::NewCommand
         << "  -d, --dir   Base directory for project creation\n"
         << "  --force     Overwrite existing directory\n\n"
 
+        << "Application workflow\n"
+        << "  cd api/\n"
+        << "  vix build\n"
+        << "  vix run\n\n"
+
+        << "Library workflow\n"
+        << "  cd tree/\n"
+        << "  vix build --build-target all\n"
+        << "  vix build --build-target all -- -Dtree_BUILD_TESTS=ON\n"
+        << "  vix tests\n\n"
+
         << "Environment\n"
         << "  VIX_NONINTERACTIVE=1   Disable prompts\n"
         << "  CI=1                   Disable prompts\n\n"
@@ -368,6 +379,8 @@ namespace vix::commands::NewCommand
         << "  • Use 'vix add <pkg>' to add dependencies\n"
         << "  • Use 'vix install' to install from vix.lock\n"
         << "  • Use 'vix task <name>' to run generated tasks\n"
+        << "  • For header-only libraries, use '--build-target all' to build the generated project\n"
+        << "  • Tests for header-only libraries are disabled by default and must be enabled with CMake args\n"
         << "  • Designed for fast start with zero setup\n";
 
     return 0;

src/commands/new/NewOutput.cpp

@@ -73,19 +73,19 @@ namespace vix::commands::new_cmd::output
     print_command_step(1, "cd " + projName + "/", "enter project");
     print_command_step(2, "vix build", "compile");
     print_command_step(3, "vix run", "start app");
-
-    std::cout << "\n";
   }
 
   static void print_steps_lib(const std::string &projName)
   {
     section("next");
 
     print_command_step(1, "cd " + projName + "/", "enter project");
-    print_command_step(2, "vix build", "compile");
-    print_command_step(3, "vix tests", "run tests");
-
-    std::cout << "\n";
+    print_command_step(2, "vix build --build-target all", "compile");
+    print_command_step(
+        3,
+        "vix build --build-target all -- -D" + projName + "_BUILD_TESTS=ON",
+        "enable tests");
+    print_command_step(4, "vix tests", "run tests");
   }
 
   // ------------------------------------------------------------------

src/commands/new/NewTemplates.cpp

@@ -251,6 +251,12 @@ namespace vix::commands::new_cmd::templates
     readme += "```\n\n";
 
     readme += "## Tests\n\n";
+    readme += "Tests are disabled by default for header-only libraries.\n\n";
+    readme += "Enable them first:\n\n";
+    readme += "```bash\n";
+    readme += "vix build --build-target all -- -D" + name + "_BUILD_TESTS=ON\n";
+    readme += "```\n\n";
+    readme += "Then run:\n\n";
     readme += "```bash\n";
     readme += "vix tests\n";
     readme += "```\n\n";

src/errors/build/CMakeBuildErrors.cpp

@@ -43,6 +43,48 @@ namespace vix::cli::errors::build
       return {};
     }
 
+    static bool handle_unknown_ninja_target(std::string_view log)
+    {
+      constexpr std::string_view marker = "ninja: error: unknown target '";
+
+      const std::size_t pos = log.find(marker);
+
+      if (pos == std::string_view::npos)
+        return false;
+
+      const std::size_t start = pos + marker.size();
+      const std::size_t end = log.find('\'', start);
+
+      std::string target = "unknown";
+
+      if (end != std::string_view::npos && end > start)
+        target = std::string(log.substr(start, end - start));
+
+      std::cerr << PAD
+                << RED << BOLD << "✖ Build target not found" << RESET
+                << "\n";
+
+      std::cerr << PAD
+                << CYAN << "target:" << RESET
+                << " "
+                << target
+                << "\n";
+
+      std::cerr << PAD
+                << YELLOW << "hint:" << RESET
+                << " "
+                << "This project does not define a CMake target named '"
+                << target
+                << "'.\n";
+
+      std::cerr << PAD
+                << "      "
+                << "Check your CMakeLists.txt or use --build-target with an existing target."
+                << "\n";
+
+      return true;
+    }
+
     bool contains(std::string_view log, std::string_view needle)
     {
       return log.find(needle) != std::string_view::npos;
@@ -570,6 +612,9 @@ namespace vix::cli::errors::build
 
   bool handleCMakeBuildError(std::string_view log)
   {
+    if (handle_unknown_ninja_target(log))
+      return true;
+
     if (handleCacheMismatch(log))
       return true;