extends SceneTree
## Runs every test script in res://tests whose file name starts with "test_".
## Every method whose name starts with "test_" is one test. A test fails if a
## check fails or if an error is reported while it runs, for example a call
## on a null value. Exits with code 1 if any test failed or if no test ran,
## so that a renamed test folder or misnamed tests cannot pass as a clean run.
##
## From the repository root:
##   godot --headless --path game -s res://tests/run_tests.gd

const TEST_DIR := "res://tests"


## Counts the errors that are reported while tests run. Warnings do not count.
class ErrorCounter extends Logger:
	var _mutex := Mutex.new()
	var _errors := 0

	func errors() -> int:
		_mutex.lock()
		var count := _errors
		_mutex.unlock()
		return count

	func _log_error(
		_function: String,
		_file: String,
		_line: int,
		_code: String,
		_rationale: String,
		_editor_notify: bool,
		error_type: int,
		_script_backtraces: Array[ScriptBacktrace]
	) -> void:
		if error_type == ERROR_TYPE_WARNING:
			return
		_mutex.lock()
		_errors += 1
		_mutex.unlock()


func _initialize() -> void:
	_run_all.call_deferred()


func _run_all() -> void:
	var counter := ErrorCounter.new()
	OS.add_logger(counter)
	var passed := 0
	var failed := 0
	var files := DirAccess.get_files_at(TEST_DIR)
	files.sort()
	for file in files:
		if not (file.begins_with("test_") and file.ends_with(".gd")):
			continue
		var script: GDScript = load(TEST_DIR.path_join(file))
		if script == null or not script.can_instantiate():
			failed += 1
			print("FAIL  %s  the script does not load; see the error above" % file)
			continue
		for method in script.get_script_method_list():
			var test_name: String = method["name"]
			if not test_name.begins_with("test_"):
				continue
			var test: TestCase = script.new()
			test.tree = self
			var errors_before := counter.errors()
			await test.call(test_name)
			var errors := counter.errors() - errors_before
			if errors > 0:
				test.failures.append("%d error(s) reported while the test ran; see above" % errors)
			if test.failures.is_empty():
				passed += 1
				print("ok    %s  %s" % [file, test_name])
			else:
				failed += 1
				print("FAIL  %s  %s" % [file, test_name])
				for failure in test.failures:
					print("        " + failure)
	OS.remove_logger(counter)
	print("%d passed, %d failed" % [passed, failed])
	quit(1 if failed > 0 or passed == 0 else 0)