Lua script screens beside the WebAssembly ones

2026-11-15 02:29:07 +01:00 · 2026-11-10 15:29:25 +01:00
parent a73585dca0
commit c4924f756d
34 changed files with 3777 additions and 1635 deletions
--- a/tests/unit/test_script_screen_host.cpp
+++ b/tests/unit/test_script_screen_host.cpp
@@ -0,0 +1,596 @@
+#include "stdafx.h"
+#include "doctest.h"
+
+// the script screen host (scripting/scriptscreens.cpp) with the real runtimes: a script reads its input, draws an
+// image that goes to the screen's texture, bottom row first, and sends a command; a script stuck in a loop is stopped;
+// a Lua script can't reach files, the system or precompiled code. the Lua cases need WITH_LUA, the WebAssembly ones
+// WITH_WASM
+
+#include "scripting/scriptscreens.h"
+#include "input/command.h"
+#include "interfaces/ITexture.h"
+#include "utilities/Globals.h"
+#include "utilities/dictionary.h"
+
+#include <array>
+#include <chrono>
+#include <filesystem>
+#include <format>
+#include <fstream>
+#include <functional>
+#include <span>
+#include <string_view>
+#include <thread>
+#include <vector>
+
+// the engine's command queue and command names, which the test build doesn't link: the commands the screens send
+// are kept here instead
+
+namespace {
+
+std::vector<std::pair<command_data, std::uint32_t>> &sent_commands() {
+	static std::vector<std::pair<command_data, std::uint32_t>> commands;
+	return commands;
+}
+
+} // namespace
+
+namespace simulation {
+command_queue Commands; // NOSONAR the engine's extern global, input/command.h
+std::unordered_map<std::string, user_command> const commandMap{{"cmdtest", user_command::aidriverenable}}; // NOSONAR the engine's extern global, input/command.h
+} // namespace simulation
+
+void command_queue::push(command_data const &Command, uint32_t const Recipient) { // NOSONAR signature from input/command.h
+	sent_commands().emplace_back(Command, Recipient);
+}
+
+namespace {
+
+// a texture that keeps what was uploaded to it
+struct recording_texture : ITexture {
+	bool create(bool) override { return true; }
+	int get_width() const override { return width; }
+	int get_height() const override { return height; }
+	size_t get_id() const override { return id; }
+	void release() override { /* nothing held */ }
+	void make_stub() override { /* nothing held */ }
+	std::string_view get_traits() const override { return ""; }
+	std::string_view get_name() const override { return "recording"; }
+	std::string_view get_type() const override { return "make:"; }
+	bool is_stub() const override { return false; }
+	bool get_has_alpha() const override { return true; }
+	bool get_is_ready() const override { return ready; }
+	void set_components_hint(int) override { /* not used */ }
+	void make_from_memory(size_t const Width, size_t const Height, const uint8_t *Data) override { update_from_memory(Width, Height, Data); }
+	void update_from_memory(size_t const Width, size_t const Height, const uint8_t *Data) override {
+		width = static_cast<int>(Width);
+		height = static_cast<int>(Height);
+		pixels.assign(Data, Data + Width * Height * 4);
+		++uploads;
+	}
+
+	bool ready{true};
+	size_t id{1};
+	int width{0};
+	int height{0};
+	int uploads{0};
+	std::vector<std::uint8_t> pixels;
+};
+
+// a folder of its own for the scripts of a test, removed with the object
+class script_folder {
+  public:
+	explicit script_folder(std::string const &Name)
+	    : m_folder{std::filesystem::temp_directory_path() / std::format("eu07_script_screen_test_{}", Name)} {
+		std::filesystem::remove_all(m_folder);
+		std::filesystem::create_directories(m_folder);
+	}
+	~script_folder() {
+		std::error_code error;
+		std::filesystem::remove_all(m_folder, error);
+	}
+	script_folder(script_folder const &) = delete;
+	script_folder &operator=(script_folder const &) = delete;
+
+	// writes the file, returns its path as the game names scripts
+	std::string write(std::string const &Name, std::span<std::uint8_t const> const Bytes) const {
+		auto const path{m_folder / Name};
+		std::filesystem::create_directories(path.parent_path());
+		std::ofstream file{path, std::ios::binary};
+		file.write(reinterpret_cast<char const *>(Bytes.data()), static_cast<std::streamsize>(Bytes.size()));
+		return path.generic_string();
+	}
+	std::string write(std::string const &Name, std::string_view const Text) const {
+		return write(Name, std::span{reinterpret_cast<std::uint8_t const *>(Text.data()), Text.size()});
+	}
+
+  private:
+	std::filesystem::path m_folder;
+};
+
+// runs frames until the condition holds, or gives up after a few seconds
+bool run_until(script_screen_queue &Queue, std::function<bool()> const &Condition) {
+	auto const deadline{std::chrono::steady_clock::now() + std::chrono::seconds(20)};
+	while (std::chrono::steady_clock::now() < deadline) {
+		Queue.update();
+		if (Condition()) {
+			return true;
+		}
+		std::this_thread::sleep_for(std::chrono::milliseconds(5));
+	}
+	return false;
+}
+
+std::shared_ptr<dictionary_source> speed(double const Value) {
+	auto input{std::make_shared<dictionary_source>()};
+	input->insert("speed", Value);
+	return input;
+}
+
+script_screen_queue::screen_request request(script_language const Language, std::string const &Script, std::string const &Key, ITexture *Texture,
+                                            script_screen_kind const Kind = script_screen_kind::cab) {
+	return {.kind = Kind, .language = Language, .script = Script, .key = Key, .texture = Texture, .frames = 0};
+}
+
+// submits a refresh as soon as the screen is due
+void refresh(script_screen_queue &Queue, std::shared_ptr<script_screen> const &Screen, std::shared_ptr<dictionary_source> Input, std::uint32_t const Vehicle) {
+	REQUIRE(run_until(Queue, [&Queue, &Screen] { return Queue.due(*Screen); }));
+	Queue.submit(Screen, std::move(Input), Vehicle);
+}
+
+} // namespace
+
+TEST_CASE("script screens: a language that doesn't run gets no screens") {
+	script_screen_queue queue;
+	// not started
+	CHECK_FALSE(queue.runs(script_language::lua));
+	CHECK(queue.acquire(request(script_language::lua, "x.lua", "x", nullptr)) == nullptr);
+}
+
+TEST_CASE("script screens: the language of a script is told by its extension") {
+	CHECK(script_language_of("scripts/led_111a20.lua") == script_language::lua);
+	CHECK(script_language_of("dynamic/pkp/x/ekran.wasm") == script_language::wasm);
+	CHECK_FALSE(script_language_of("scripts/led_111a20").has_value());
+}
+
+#ifdef WITH_WASM
+
+namespace {
+
+// the modules, encoded by hand. "paint": a 2x2 screen in the colour 0xFF0000vv, vv being the input value
+// "speed", which sends the command "cmdtest" with the parameters (vv, 7):
+//   (import "eu07" "get_float" (func $get_float (param i32 i32) (result f64)))
+//   (import "eu07" "command" (func $command (param i32 i32 i32 i32)))
+//   (memory (export "memory") 1)
+//   (data (i32.const 0) "speed") (data (i32.const 16) "cmdtest")
+//   (func (export "screen_width") (result i32) i32.const 2)
+//   (func (export "screen_height") (result i32) i32.const 2)
+//   (func (export "screen_render") (result i32) (local $v i32)
+//     (local.set $v (i32.trunc_f64_s (call $get_float (i32.const 0) (i32.const 5))))
+//     (i32.store (i32.const 1024) (i32.or (local.get $v) (i32.const 0xFF000000))) ... the same at 1028, 1032, 1036
+//     (call $command (i32.const 16) (i32.const 7) (local.get $v) (i32.const 7))
+//     (i32.const 1024))
+constexpr std::array<std::uint8_t, 254> paint_module{
+	0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x12, 0x03, 0x60, 0x02, 0x7f, 0x7f, 0x01,
+	0x7c, 0x60, 0x04, 0x7f, 0x7f, 0x7f, 0x7f, 0x00, 0x60, 0x00, 0x01, 0x7f, 0x02, 0x21, 0x02, 0x04,
+	0x65, 0x75, 0x30, 0x37, 0x09, 0x67, 0x65, 0x74, 0x5f, 0x66, 0x6c, 0x6f, 0x61, 0x74, 0x00, 0x00,
+	0x04, 0x65, 0x75, 0x30, 0x37, 0x07, 0x63, 0x6f, 0x6d, 0x6d, 0x61, 0x6e, 0x64, 0x00, 0x01, 0x03,
+	0x04, 0x03, 0x02, 0x02, 0x02, 0x05, 0x03, 0x01, 0x00, 0x01, 0x07, 0x39, 0x04, 0x06, 0x6d, 0x65,
+	0x6d, 0x6f, 0x72, 0x79, 0x02, 0x00, 0x0c, 0x73, 0x63, 0x72, 0x65, 0x65, 0x6e, 0x5f, 0x77, 0x69,
+	0x64, 0x74, 0x68, 0x00, 0x02, 0x0d, 0x73, 0x63, 0x72, 0x65, 0x65, 0x6e, 0x5f, 0x68, 0x65, 0x69,
+	0x67, 0x68, 0x74, 0x00, 0x03, 0x0d, 0x73, 0x63, 0x72, 0x65, 0x65, 0x6e, 0x5f, 0x72, 0x65, 0x6e,
+	0x64, 0x65, 0x72, 0x00, 0x04, 0x0a, 0x5e, 0x03, 0x04, 0x00, 0x41, 0x02, 0x0b, 0x04, 0x00, 0x41,
+	0x02, 0x0b, 0x52, 0x01, 0x01, 0x7f, 0x41, 0x00, 0x41, 0x05, 0x10, 0x00, 0xaa, 0x21, 0x00, 0x41,
+	0x80, 0x08, 0x20, 0x00, 0x41, 0x80, 0x80, 0x80, 0x78, 0x72, 0x36, 0x02, 0x00, 0x41, 0x84, 0x08,
+	0x20, 0x00, 0x41, 0x80, 0x80, 0x80, 0x78, 0x72, 0x36, 0x02, 0x00, 0x41, 0x88, 0x08, 0x20, 0x00,
+	0x41, 0x80, 0x80, 0x80, 0x78, 0x72, 0x36, 0x02, 0x00, 0x41, 0x8c, 0x08, 0x20, 0x00, 0x41, 0x80,
+	0x80, 0x80, 0x78, 0x72, 0x36, 0x02, 0x00, 0x41, 0x10, 0x41, 0x07, 0x20, 0x00, 0x41, 0x07, 0x10,
+	0x01, 0x41, 0x80, 0x08, 0x0b, 0x0b, 0x17, 0x02, 0x00, 0x41, 0x00, 0x0b, 0x05, 0x73, 0x70, 0x65,
+	0x65, 0x64, 0x00, 0x41, 0x10, 0x0b, 0x07, 0x63, 0x6d, 0x64, 0x74, 0x65, 0x73, 0x74};
+
+// "spin": exports the same functions as "paint", but screen_render never returns: (loop $l (br $l))
+constexpr std::array<std::uint8_t, 108> spin_module{
+	0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x05, 0x01, 0x60, 0x00, 0x01, 0x7f, 0x03,
+	0x04, 0x03, 0x00, 0x00, 0x00, 0x05, 0x03, 0x01, 0x00, 0x01, 0x07, 0x39, 0x04, 0x06, 0x6d, 0x65,
+	0x6d, 0x6f, 0x72, 0x79, 0x02, 0x00, 0x0c, 0x73, 0x63, 0x72, 0x65, 0x65, 0x6e, 0x5f, 0x77, 0x69,
+	0x64, 0x74, 0x68, 0x00, 0x00, 0x0d, 0x73, 0x63, 0x72, 0x65, 0x65, 0x6e, 0x5f, 0x68, 0x65, 0x69,
+	0x67, 0x68, 0x74, 0x00, 0x01, 0x0d, 0x73, 0x63, 0x72, 0x65, 0x65, 0x6e, 0x5f, 0x72, 0x65, 0x6e,
+	0x64, 0x65, 0x72, 0x00, 0x02, 0x0a, 0x15, 0x03, 0x04, 0x00, 0x41, 0x02, 0x0b, 0x04, 0x00, 0x41,
+	0x02, 0x0b, 0x09, 0x00, 0x03, 0x40, 0x0c, 0x00, 0x0b, 0x41, 0x00, 0x0b};
+
+} // namespace
+
+TEST_CASE("wasm screens: a cab screen draws from its input and sends commands to its vehicle") {
+	sent_commands().clear();
+	script_folder const folder{"wasm_paint"};
+	auto const module{folder.write("paint.wasm", paint_module)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+	REQUIRE(queue.runs(script_language::wasm));
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::wasm, module, "cab", &texture))};
+	REQUIRE(screen != nullptr);
+	// the same key, the same screen
+	CHECK(queue.acquire(request(script_language::wasm, module, "cab", &texture)) == screen);
+
+	refresh(queue, screen, speed(5.0), 42);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0 && false == sent_commands().empty(); }));
+
+	CHECK(texture.width == 2);
+	CHECK(texture.height == 2);
+	REQUIRE(texture.pixels.size() == 16);
+	std::array<std::uint8_t, 4> const expected{0x05, 0x00, 0x00, 0xFF};
+	for (std::size_t pixel = 0; pixel < 4; ++pixel) {
+		CAPTURE(pixel);
+		CHECK(std::equal(expected.begin(), expected.end(), texture.pixels.begin() + static_cast<std::ptrdiff_t>(pixel * 4)));
+	}
+
+	REQUIRE(sent_commands().size() == 1);
+	auto const &[command, recipient]{sent_commands().front()};
+	CHECK(command.command == user_command::aidriverenable);
+	CHECK(command.param1 == 5.0);
+	CHECK(command.param2 == 7.0);
+	CHECK(recipient == (static_cast<std::uint32_t>(command_target::vehicle) | 42u));
+
+	queue.exit();
+}
+
+TEST_CASE("wasm screens: the image goes up again when the texture is made anew, and waits while it isn't there") {
+	sent_commands().clear();
+	script_folder const folder{"wasm_reupload"};
+	auto const module{folder.write("paint.wasm", paint_module)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	texture.ready = false;
+	auto const screen{queue.acquire(request(script_language::wasm, module, "cab", &texture))};
+	refresh(queue, screen, speed(9.0), 1);
+	REQUIRE(run_until(queue, [] { return false == sent_commands().empty(); }));
+	queue.update();
+	CHECK(texture.uploads == 0);
+
+	texture.ready = true;
+	queue.update();
+	CHECK(texture.uploads == 1);
+	queue.update();
+	CHECK(texture.uploads == 1);
+
+	// released and made again: a new gl texture
+	texture.id = 2;
+	queue.update();
+	CHECK(texture.uploads == 2);
+
+	queue.exit();
+}
+
+TEST_CASE("wasm screens: a screen outside the cab draws, but its commands are dropped") {
+	sent_commands().clear();
+	script_folder const folder{"wasm_sign"};
+	auto const module{folder.write("paint.wasm", paint_module)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::wasm, module, "sign", &texture, script_screen_kind::external))};
+	refresh(queue, screen, speed(3.0), 0);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0; }));
+	queue.update();
+	CHECK(sent_commands().empty());
+
+	queue.exit();
+}
+
+TEST_CASE("wasm screens: a screen stuck in a loop is stopped, and the others keep working") {
+	script_folder const folder{"wasm_spin"};
+	auto const spinning{folder.write("spin.wasm", spin_module)};
+	auto const painting{folder.write("paint.wasm", paint_module)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture stuck;
+	recording_texture working;
+	auto const first{queue.acquire(request(script_language::wasm, spinning, "spin", &stuck))};
+	auto const second{queue.acquire(request(script_language::wasm, painting, "paint", &working))};
+	refresh(queue, first, speed(1.0), 1);
+	refresh(queue, second, speed(2.0), 1);
+
+	REQUIRE(run_until(queue, [&working] { return working.uploads > 0; }));
+	CHECK(stuck.uploads == 0);
+	// the stuck screen ran first, into the instruction limit, and isn't due any more
+	CHECK_FALSE(queue.due(*first));
+
+	queue.exit();
+}
+
+TEST_CASE("wasm screens: the screens outlive the queue without harm") {
+	script_folder const folder{"wasm_outlive"};
+	auto const module{folder.write("paint.wasm", paint_module)};
+	std::shared_ptr<script_screen> screen;
+	recording_texture texture;
+	{
+		script_screen_queue queue;
+		REQUIRE(queue.init());
+		screen = queue.acquire(request(script_language::wasm, module, "cab", &texture));
+		refresh(queue, screen, speed(4.0), 1);
+		REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0; }));
+	}
+	// the queue and the runtime are gone, the vehicle still holds its screen
+	CHECK(screen != nullptr);
+	screen.reset();
+}
+
+#endif
+
+#ifdef WITH_LUA
+
+#include "stb/stb_image.h"
+#include "stb/stb_image_write.h"
+
+namespace {
+
+// the game's texture loader turns every image stb_image reads bottom row first (model/Texture.cpp); for the length of
+// a test, the same here
+class images_flipped_as_in_the_game {
+  public:
+	images_flipped_as_in_the_game() { stbi_set_flip_vertically_on_load(1); }
+	~images_flipped_as_in_the_game() { stbi_set_flip_vertically_on_load(0); }
+	images_flipped_as_in_the_game(images_flipped_as_in_the_game const &) = delete;
+	images_flipped_as_in_the_game &operator=(images_flipped_as_in_the_game const &) = delete;
+};
+
+// a 2x2 screen in the colour (speed, 0, 0), sending the command "cmdtest" with (speed, 7)
+constexpr std::string_view paint_script{R"(
+local screen = {}
+function screen.render(state)
+	eu07.command("cmdtest", state.speed, 7)
+	return eu07.image(2, 2, { state.speed, 0, 0 })
+end
+return screen
+)"};
+
+// 1x2: a red row above a green one
+constexpr std::string_view rows_script{R"(
+return {
+	render = function(state)
+		local image = eu07.image(1, 2, { 0, 0, 0 })
+		image:set(0, 0, { 255, 0, 0 })
+		image:set(0, 1, { 0, 255, 0 })
+		return image
+	end
+}
+)"};
+
+// 1x1, white when nothing of the world outside the sandbox is reachable, black otherwise
+constexpr std::string_view sandbox_script{R"(
+local reachable = io or os or ffi or debug or package or require or load or loadstring or dofile or loadfile or string.dump or jit
+local escapes = eu07.read_file("../outside.txt") or eu07.read_file("/etc/hosts") or eu07.read_file("c:/windows/win.ini")
+local inside = eu07.read_file("data/inside.txt")
+local ok = not reachable and not escapes and inside == "inside"
+return {
+	render = function(state)
+		return eu07.image(1, 1, ok and { 255, 255, 255 } or { 0, 0, 0 })
+	end
+}
+)"};
+
+// never returns from render
+constexpr std::string_view spin_script{R"(
+return { render = function(state) while true do end end }
+)"};
+
+// draws once, then reports nothing new
+constexpr std::string_view once_script{R"(
+local drawn = false
+return {
+	render = function(state)
+		if drawn then return nil end
+		drawn = true
+		return eu07.image(1, 1, { 1, 2, 3 })
+	end
+}
+)"};
+
+// uses a helper script and a font next to it
+constexpr std::string_view include_script{R"(
+local helper = eu07.include("helper.lua")
+local font = eu07.font("font/test")
+return {
+	render = function(state)
+		local image = eu07.image(8, 2, { 0, 0, 0 })
+		local x = image:draw_text(font, 0, 0, helper.text, { 255, 0, 0 })
+		image:set(7, 1, { x, font:text_width("ab"), font:height() })
+		return image
+	end
+}
+)"};
+
+constexpr std::string_view helper_script{R"(
+return { text = "ab" }
+)"};
+
+// a font of two glyphs a column apart: "a" two columns wide, lit in its top row, "b" one column, lit in both rows.
+// written as a .png by stb_image_write, the way the game's fonts are
+std::vector<std::uint8_t> test_font_png() {
+	constexpr int width{4};
+	constexpr int height{2};
+	std::array<std::uint8_t, width * height * 4> pixels{};
+	pixels.fill(255);
+	auto const lit{[&pixels](int const X, int const Y) { pixels[(Y * width + X) * 4] = 0; }};
+	lit(0, 0);
+	lit(1, 0);
+	lit(3, 0);
+	lit(3, 1);
+	std::vector<std::uint8_t> result;
+	auto const append{[](void *Target, void *Data, int const Size) {
+		auto *bytes{static_cast<std::uint8_t const *>(Data)};
+		static_cast<std::vector<std::uint8_t> *>(Target)->insert(static_cast<std::vector<std::uint8_t> *>(Target)->end(), bytes, bytes + Size);
+	}};
+	stbi_write_png_to_func(append, &result, width, height, 4, pixels.data(), width * 4);
+	return result;
+}
+
+} // namespace
+
+TEST_CASE("lua screens: a cab screen draws from its input and sends commands to its vehicle") {
+	sent_commands().clear();
+	script_folder const folder{"lua_paint"};
+	auto const script{folder.write("paint.lua", paint_script)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+	REQUIRE(queue.runs(script_language::lua));
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::lua, script, "cab", &texture))};
+	REQUIRE(screen != nullptr);
+	refresh(queue, screen, speed(5.0), 42);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0 && false == sent_commands().empty(); }));
+
+	CHECK(texture.width == 2);
+	CHECK(texture.height == 2);
+	REQUIRE(texture.pixels.size() == 16);
+	CHECK(texture.pixels[0] == 5);
+	CHECK(texture.pixels[1] == 0);
+	CHECK(texture.pixels[3] == 255);
+
+	REQUIRE(sent_commands().size() == 1);
+	auto const &[command, recipient]{sent_commands().front()};
+	CHECK(command.command == user_command::aidriverenable);
+	CHECK(command.param1 == 5.0);
+	CHECK(command.param2 == 7.0);
+	CHECK(recipient == (static_cast<std::uint32_t>(command_target::vehicle) | 42u));
+	queue.exit();
+}
+
+TEST_CASE("lua screens: the texture gets the bottom row first, as from the python screens") {
+	script_folder const folder{"lua_rows"};
+	auto const script{folder.write("rows.lua", rows_script)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::lua, script, "rows", &texture))};
+	refresh(queue, screen, speed(0.0), 1);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0; }));
+	REQUIRE(texture.pixels.size() == 8);
+	// green, the bottom row, first
+	CHECK(texture.pixels[0] == 0);
+	CHECK(texture.pixels[1] == 255);
+	CHECK(texture.pixels[4] == 255);
+	CHECK(texture.pixels[5] == 0);
+	queue.exit();
+}
+
+TEST_CASE("lua screens: a script reaches no files outside its folder, nor the system, nor ffi") {
+	script_folder const folder{"lua_sandbox"};
+	folder.write("../outside.txt", std::string_view{"outside"});
+	folder.write("data/inside.txt", std::string_view{"inside"});
+	auto const script{folder.write("sandbox.lua", sandbox_script)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::lua, script, "sandbox", &texture))};
+	refresh(queue, screen, speed(0.0), 1);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0; }));
+	REQUIRE(texture.pixels.size() == 4);
+	CHECK(texture.pixels[0] == 255);
+	queue.exit();
+	std::filesystem::remove(std::filesystem::temp_directory_path() / "outside.txt");
+}
+
+TEST_CASE("lua screens: precompiled code isn't loaded") {
+	script_folder const folder{"lua_bytecode"};
+	// LuaJIT bytecode starts with ESC "LJ"
+	auto const script{folder.write("compiled.lua", std::string_view{"\x1bLJ\x02\x00 not a script"})};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::lua, script, "compiled", &texture))};
+	refresh(queue, screen, speed(0.0), 1);
+	// it fails to load, and isn't refreshed again: a screen that runs would be due again within a few frames
+	for (int frame = 0; frame < 40; ++frame) {
+		queue.update();
+		std::this_thread::sleep_for(std::chrono::milliseconds(5));
+	}
+	CHECK_FALSE(queue.due(*screen));
+	CHECK(texture.uploads == 0);
+	queue.exit();
+}
+
+TEST_CASE("lua screens: a script stuck in a loop is stopped, and the others keep working") {
+	script_folder const folder{"lua_spin"};
+	auto const spinning{folder.write("spin.lua", spin_script)};
+	auto const painting{folder.write("paint.lua", paint_script)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture stuck;
+	recording_texture working;
+	auto const first{queue.acquire(request(script_language::lua, spinning, "spin", &stuck))};
+	auto const second{queue.acquire(request(script_language::lua, painting, "paint", &working))};
+	refresh(queue, first, speed(1.0), 1);
+	refresh(queue, second, speed(2.0), 1);
+
+	REQUIRE(run_until(queue, [&working] { return working.uploads > 0; }));
+	CHECK(stuck.uploads == 0);
+	CHECK_FALSE(queue.due(*first));
+	queue.exit();
+}
+
+TEST_CASE("lua screens: nil from render keeps the image there is") {
+	script_folder const folder{"lua_once"};
+	auto const script{folder.write("once.lua", once_script)};
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::lua, script, "once", &texture))};
+	refresh(queue, screen, speed(0.0), 1);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0; }));
+	refresh(queue, screen, speed(0.0), 1);
+	refresh(queue, screen, speed(0.0), 1);
+	for (int frame = 0; frame < 20; ++frame) {
+		queue.update();
+		std::this_thread::sleep_for(std::chrono::milliseconds(5));
+	}
+	CHECK(texture.uploads == 1);
+	CHECK(texture.pixels[2] == 3);
+	queue.exit();
+}
+
+TEST_CASE("lua screens: a script includes another and reads a font of the python screens' format") {
+	script_folder const folder{"lua_include"};
+	auto const script{folder.write("include.lua", include_script)};
+	folder.write("helper.lua", helper_script);
+	folder.write("font/test.png", test_font_png());
+	folder.write("font/test.txt", std::string_view{"// a comment line\r\na2\r\nb1\r\n"});
+	// the fonts are read top row first all the same
+	images_flipped_as_in_the_game const flipped;
+	script_screen_queue queue;
+	REQUIRE(queue.init());
+
+	recording_texture texture;
+	auto const screen{queue.acquire(request(script_language::lua, script, "include", &texture))};
+	refresh(queue, screen, speed(0.0), 1);
+	REQUIRE(run_until(queue, [&texture] { return texture.uploads > 0; }));
+	REQUIRE(texture.pixels.size() == 8 * 2 * 4);
+	// bottom row first: the top row of the image is the second row of the texture
+	auto const top{[&texture](int const X) { return texture.pixels[(8 + X) * 4]; }};
+	auto const bottom{[&texture](int const X) { return texture.pixels[X * 4]; }};
+	CHECK(top(0) == 255);
+	CHECK(top(1) == 255);
+	CHECK(top(2) == 0); // the spacing column
+	CHECK(top(3) == 255);
+	CHECK(bottom(0) == 0);
+	CHECK(bottom(3) == 255);
+	// the x after the text (2 + 1 + 1 + 1), its width and the font's height
+	CHECK(texture.pixels[7 * 4] == 5);
+	CHECK(texture.pixels[7 * 4 + 1] == 5);
+	CHECK(texture.pixels[7 * 4 + 2] == 2);
+	queue.exit();
+}
+
+#endif