Validate POC A and POC B foundations

tests/run_load_checks.gd

@@ -0,0 +1,64 @@
+extends SceneTree
+
+const SEARCH_ROOTS := [
+	"res://src",
+	"res://game",
+	"res://content",
+	"res://scenes",
+	"res://tests",
+]
+
+var _failures: Array[String] = []
+var _loaded_resource_count := 0
+
+
+func _init() -> void:
+	_run.call_deferred()
+
+
+func _run() -> void:
+	for root: String in SEARCH_ROOTS:
+		if DirAccess.dir_exists_absolute(root):
+			_load_directory(root)
+
+	if _failures.is_empty():
+		print("Resource loading: %d passed, 0 failed." % _loaded_resource_count)
+		quit(0)
+	else:
+		for failure: String in _failures:
+			push_error(failure)
+		print("Resource loading: %d failed." % _failures.size())
+		quit(1)
+
+
+func _load_directory(directory_path: String) -> void:
+	var directory := DirAccess.open(directory_path)
+	if directory == null:
+		_failures.append("cannot open %s" % directory_path)
+		return
+
+	var subdirectories := directory.get_directories()
+	for subdirectory: String in subdirectories:
+		_load_directory(directory_path.path_join(subdirectory))
+
+	var files := directory.get_files()
+	for file_name: String in files:
+		if not (
+			file_name.ends_with(".gd")
+			or file_name.ends_with(".tscn")
+			or file_name.ends_with(".tres")
+			or file_name.ends_with(".res")
+		):
+			continue
+		var resource_path := directory_path.path_join(file_name)
+		var resource := ResourceLoader.load(resource_path)
+		if resource == null:
+			_failures.append("cannot load %s" % resource_path)
+			continue
+		if resource is PackedScene:
+			var instance := (resource as PackedScene).instantiate()
+			if instance == null:
+				_failures.append("cannot instantiate %s" % resource_path)
+				continue
+			instance.free()
+		_loaded_resource_count += 1