new `CmdGroupMgr:get_cmd_groups()` method

test/cmdtest_d/include/group_mgr.py

@@ -44,6 +44,14 @@ class CmdGroupMgr:
 		self.network_id = cfg._proto.coin.lower() + ('_tn' if cfg._proto.testnet else '')
 		self.name = type(self).__name__
 
+	@classmethod
+	def get_cmd_groups(cls, cfg):
+		exclude = cfg.exclude_groups.split(',') if cfg.exclude_groups else []
+		for e in exclude:
+			if e not in cmd_groups_dfl:
+				die(1, f'{e!r}: group not recognized')
+		return [s for s in cmd_groups_dfl if s not in exclude]
+
 	def create_cmd_group(self, cls, sg_name=None):
 
 		cmd_group_in = dict(cls.cmd_group_in)

test/cmdtest_d/include/runner.py

@@ -360,14 +360,7 @@ class CmdTestRunner:
 					else:
 						die(1, f'{arg!r}: command not recognized')
 		else:
-			if self.cfg.exclude_groups:
-				exclude = self.cfg.exclude_groups.split(',')
-				for e in exclude:
-					if e not in cmd_groups_dfl:
-						die(1, f'{e!r}: group not recognized')
-			for gname in cmd_groups_dfl:
-				if self.cfg.exclude_groups and gname in exclude:
-					continue
+			for gname in CmdGroupMgr.get_cmd_groups(self.cfg):
 				if self.init_group(gname):
 					for cmd in self.gm.cmd_list:
 						self.check_needs_rerun(cmd, build=True)