Create test system using doctest

-Tests are run by running the project with the `--runTests` arg
-Test files are only compiled into debug builds
-Added test workflow to run on PRs
-Created new helper macro to not run functions in editor
-Wrote a few simple tests for the CellSpawner class

.github/workflows/test.yml

@@ -0,0 +1,39 @@
+name: Unit Tests
+
+on: 
+  pull_request:
+    types: [opened, edited, reopened, synchronize]
+
+jobs:
+  ci:
+    name: Run Unit Tests
+    runs-on: ubuntu-latest
+    container:
+      image: barichello/godot-ci:4.2.1
+
+    steps:
+      - name: Check out Git repository
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - name: Set up Python (for SCons)
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+
+      - name: Install scons
+        run: |
+          python -m pip install scons==4.0.0
+
+      - name: Build module
+        run: |
+          cd godot-cpp
+          scons platform=linux target=template_debug
+          cd ..
+          scons platform=linux target=template_debug disable_exceptions=no
+
+      - name: Run tests
+        run: |
+          set -e
+          godot --headless -T

.gitignore

@@ -5,5 +5,6 @@ bin/*.exp
 bin/*.lib
 .sconsign.dblite
 src/*.obj
+tests/*.obj
 .vscode/
 compile_commands.json

.gitmodules

@@ -2,3 +2,6 @@
 	path = godot-cpp
 	url = https://github.com/godotengine/godot-cpp
 	branch = 4.1
+[submodule "doctest"]
+	path = doctest
+	url = https://github.com/doctest/doctest.git

SConstruct

@@ -13,9 +13,13 @@ env = SConscript("godot-cpp/SConstruct")
 # - LINKFLAGS are for linking flags
 
 # tweak this if you want to use different folders, or more folders, to store your source code in.
-env.Append(CPPPATH=["src/"])
+env.Append(CPPPATH=["src/","tests/","doctest/doctest/"])
 sources = Glob("src/*.cpp")
 
+# If non-release build, compile the test files
+if env.debug_features:
+	sources.extend(Glob("tests/*.cpp"))
+
 if env["platform"] == "macos":
     library = env.SharedLibrary(
         "bin/libalife.{}.{}.framework/libalife.{}.{}".format(

src/cell.cpp

@@ -4,6 +4,8 @@
 #include <godot_cpp/classes/sprite2d.hpp>
 #include <godot_cpp/core/class_db.hpp>
 
+#include "helpers.hpp"
+
 using namespace godot;
 
 void Cell::_bind_methods() {
@@ -48,9 +50,7 @@ void Cell::_ready() {
 }
 
 void Cell::_process(double delta) {
-	// Don't run if in editor
-	if (Engine::get_singleton()->is_editor_hint())
-		return;
+	DONT_RUN_IN_EDITOR;
 
 	if (_cellState->getAlive()) {
 		// Living Cell behavior

src/cell_spawner.cpp

@@ -3,6 +3,19 @@
 
 #include <godot_cpp/core/class_db.hpp>
 
+#include "helpers.hpp"
+
+// These includes are for starting testing and should stay with the class we're using as the project entry point
+#ifdef DEBUG_ENABLED
+#include <godot_cpp/classes/os.hpp>
+#include <godot_cpp/classes/scene_tree.hpp>
+
+#include <string>
+#include <vector>
+
+#include "TestHeader.hpp"
+#endif
+
 using namespace godot;
 
 void CellSpawner::_bind_methods() {
@@ -33,7 +46,10 @@ void CellSpawner::_bind_methods() {
 }
 
 CellSpawner::CellSpawner() { rand.instantiate(); }
-CellSpawner::~CellSpawner() {}
+CellSpawner::~CellSpawner() {
+	// Clean up spawned child nodes
+	queue_free();
+}
 
 void CellSpawner::setCellScene(const Ref<PackedScene> cellScene) {
 	_cellScene = cellScene;
@@ -88,7 +104,24 @@ void CellSpawner::spawnCell() {
 }
 
 void CellSpawner::_ready() {
-	// Don't run if in editor
-	if (Engine::get_singleton()->is_editor_hint())
-		return;
+	DONT_RUN_IN_EDITOR;
+
+	// If not in a release build, check for custom cmdline arg to run tests,
+	// forwarding additional user args into doctest as its args
+#ifdef DEBUG_ENABLED
+	for (auto arg : OS::get_singleton()->get_cmdline_args()) {
+		if (arg == "--runTests" || arg == "-T") {
+			// Collect user command line args to pass into doctest
+			std::vector<const char *> userArgs;
+			for (godot::String arg : OS::get_singleton()->get_cmdline_user_args()) {
+				const char *charArg = arg.ascii().get_data();
+				userArgs.push_back(charArg);
+			}
+
+			// Run the tests, exit, and return the value doctest returned
+			int retVal = doctest_run(userArgs.size(), userArgs.data());
+			get_tree()->quit(retVal);
+		}
+	}
+#endif
 }

src/cell_spawner.hpp

@@ -1,12 +1,12 @@
 #pragma once
 
 #include <godot_cpp/classes/engine.hpp>
-#include <godot_cpp/classes/viewport.hpp>
 #include <godot_cpp/classes/node.hpp>
 #include <godot_cpp/classes/packed_scene.hpp>
 #include <godot_cpp/classes/random_number_generator.hpp>
 #include <godot_cpp/classes/ref.hpp>
 #include <godot_cpp/classes/sprite2d.hpp>
+#include <godot_cpp/classes/viewport.hpp>
 
 namespace godot {
 

src/fps_counter.cpp

@@ -2,6 +2,8 @@
 
 #include <godot_cpp/core/class_db.hpp>
 
+#include "helpers.hpp"
+
 using namespace godot;
 
 void FpsCounter::_bind_methods() {}
@@ -10,9 +12,7 @@ FpsCounter::FpsCounter() {}
 FpsCounter::~FpsCounter() {}
 
 void FpsCounter::_process(double delta) {
-	// Don't run if in editor
-	if (Engine::get_singleton()->is_editor_hint())
-		return;
+	DONT_RUN_IN_EDITOR;
 
 	const String fps =
 			"FPS " + String::num(Engine::get_singleton()->get_frames_per_second());

src/helpers.hpp

@@ -0,0 +1,10 @@
+#pragma once
+
+#ifdef DEBUG_ENABLED
+#define DONT_RUN_IN_EDITOR                           \
+	if (Engine::get_singleton()->is_editor_hint()) { \
+		return;                                      \
+	}
+#else
+#define DONT_RUN_IN_EDITOR
+#endif

src/start_button.cpp

@@ -2,6 +2,8 @@
 
 #include <godot_cpp/core/class_db.hpp>
 
+#include "helpers.hpp"
+
 using namespace godot;
 
 void StartButton::_bind_methods() {
@@ -16,7 +18,7 @@ StartButton::~StartButton() {
 // _pressed is used as the function for when the button is pressed
 //  This button is also switching the button off once it gets pressed once.
 void StartButton::_pressed() {
-	CellSpawner *parent = (CellSpawner *)this->get_parent();
+	CellSpawner *parent = static_cast<CellSpawner *>(this->get_parent());
 	for (int i = 0; i < parent->getNumCells(); i++) {
 		parent->spawnCell();
 	}
@@ -26,9 +28,7 @@ void StartButton::_pressed() {
 // Mainly used for setting diffrent values for the button but these could be done in the godot client instead
 //
 void StartButton::_ready() {
-	// Don't run if in editor
-	if (Engine::get_singleton()->is_editor_hint())
-		return;
+	DONT_RUN_IN_EDITOR;
 
 	this->set_text("Start");
 }

src/start_button.hpp

@@ -1,8 +1,8 @@
 #pragma once
 
 #include "cell_spawner.hpp"
-#include <godot_cpp/classes/engine.hpp>
 #include <godot_cpp/classes/button.hpp>
+#include <godot_cpp/classes/engine.hpp>
 
 namespace godot {
 

src/stats_counter.cpp

@@ -3,6 +3,8 @@
 
 #include <godot_cpp/core/class_db.hpp>
 
+#include "helpers.hpp"
+
 using namespace godot;
 
 void StatsCounter::_bind_methods() {}
@@ -11,9 +13,7 @@ StatsCounter::StatsCounter() {}
 StatsCounter::~StatsCounter() {}
 
 void StatsCounter::_process(double delta) {
-	// Don't run if in editor
-	if (Engine::get_singleton()->is_editor_hint())
-		return;
+	DONT_RUN_IN_EDITOR;
 
 	const String stats = "COLLISIONS " + String::num(Cell::CollisionCount);
 	set_text(stats);

tests/TestCellSpawner.cpp

@@ -0,0 +1,36 @@
+#include "TestHeader.hpp"
+
+#include "cell_spawner.hpp"
+
+#include <godot_cpp/classes/Object.hpp>
+
+namespace godot {
+
+TEST_CASE("Dummy") {
+	CHECK(1 == 1);
+}
+
+TEST_CASE("Test CellSpawner") {
+	CellSpawner CellSpawner{};
+
+	REQUIRE(CellSpawner.getMinForce() == 50.0);
+	REQUIRE(CellSpawner.getMaxForce() == 150.0);
+
+	SUBCASE("Test setting min force") {
+		CellSpawner.setMinForce(40.0);
+		CHECK(CellSpawner.getMinForce() == 40.0);
+
+		CellSpawner.setMinForce(CellSpawner.getMaxForce() + 1);
+		CHECK(CellSpawner.getMinForce() == CellSpawner.getMaxForce());
+	}
+
+	SUBCASE("Test setting max force") {
+		CellSpawner.setMaxForce(160.0);
+		CHECK(CellSpawner.getMaxForce() == 160.0);
+
+		CellSpawner.setMaxForce(CellSpawner.getMinForce() - 1);
+		CHECK(CellSpawner.getMaxForce() == CellSpawner.getMinForce());
+	}
+}
+
+} //namespace godot

tests/TestHeader.hpp

@@ -0,0 +1,5 @@
+#pragma once
+
+#include "doctest.h"
+
+int doctest_run(const int, const char *const *);

tests/TestMain.cpp

@@ -0,0 +1,15 @@
+// Can only be used in one test file. Do not copy!!
+#define DOCTEST_CONFIG_IMPLEMENT
+
+#include "TestHeader.hpp"
+
+#include <string>
+#include <vector>
+
+int doctest_run(const int argc, const char *const *argv) {
+	doctest::Context context;
+	context.applyCommandLine(argc, argv);
+	int res = context.run();
+
+	return res;
+}