Validate gameplay metadata before publishing build generations

tests/build_schema_tool.cpp

@@ -0,0 +1,50 @@
+#include <faset/core/io.hpp>
+#include <iostream>
+
+// Native stand-in for CMake and SchemaExporter. Tests exercise the real
+// asynchronous BuildService and publication code without compiling a game.
+namespace fs = std::filesystem;
+using namespace faset;
+int tool_main(int argc, char** argv) {
+    try {
+        if (argc == 3 && std::string_view(argv[1]) == "--output") {
+            atomic_write_json(path_from_utf8(argv[2]), read_json("schema-fixture.json"));
+            return 0;
+        }
+        if (argc > 2 && std::string_view(argv[1]) == "--build")
+            return 0;
+        fs::path build;
+        for (int i = 1; i + 1 < argc; ++i)
+            if (std::string_view(argv[i]) == "-B")
+                build = path_from_utf8(argv[i + 1]);
+        if (build.empty())
+            throw std::runtime_error("Fixture expects CMake configure or SchemaExporter arguments");
+        fs::create_directories(build / "shaders");
+        atomic_write(build / "CMakeCache.txt", "Native schema publication fixture\n");
+        const auto self = fs::absolute(path_from_utf8(argv[0]));
+#ifdef _WIN32
+        constexpr auto suffix = ".exe";
+#else
+        constexpr auto suffix = "";
+#endif
+        for (const auto* target : {"faset_player", "faset_schema_exporter"})
+            fs::copy_file(self, build / (std::string(target) + suffix),
+                          fs::copy_options::overwrite_existing);
+        for (const auto* entry : {"vertexMain", "fragmentMain", "shadowMain"})
+            for (const auto* extension : {".spv", ".reflection.json"})
+                atomic_write(build / "shaders" / (std::string(entry) + extension), "fixture\n");
+        return 0;
+    } catch (const std::exception& error) {
+        std::cerr << error.what() << '\n';
+        return 1;
+    }
+}
+#ifdef _WIN32
+int wmain(int argc, wchar_t** argv) {
+    return run_utf8_main(argc, argv, tool_main);
+}
+#else
+int main(int argc, char** argv) {
+    return tool_main(argc, argv);
+}
+#endif