diff --git a/gita/__main__.py b/gita/__main__.py
index de818a1..ba0d270 100644
--- a/gita/__main__.py
+++ b/gita/__main__.py
@@ -46,7 +46,7 @@ def f_ll(args: argparse.Namespace):
     """
     repos = utils.get_repos()
     if args.group:  # only display repos in this group
-        group_repos = utils.get_groups()[args.group].split()
+        group_repos = utils.get_groups()[args.group]
         repos = {k: repos[k] for k in group_repos if k in repos}
     for line in utils.describe(repos):
         print(line)
@@ -66,15 +66,15 @@ def f_group(args: argparse.Namespace):
     if args.to_group:
         gname = input('group name? ')
         if gname in groups:
-            gname_repos = set(groups[gname].split())
+            gname_repos = set(groups[gname])
             gname_repos.update(args.to_group)
-            groups[gname] = ' '.join(sorted(gname_repos))
+            groups[gname] = sorted(gname_repos)
             utils.write_to_groups_file(groups, 'w')
         else:
-            utils.write_to_groups_file({gname: ' '.join(sorted(args.to_group))}, 'a+')
+            utils.write_to_groups_file({gname: sorted(args.to_group)}, 'a+')
     else:
         for group, repos in groups.items():
-            print(f"{group}: {repos}")
+            print(f"{group}: {', '.join(repos)}")
 
 
 def f_ungroup(args: argparse.Namespace):
@@ -82,9 +82,9 @@ def f_ungroup(args: argparse.Namespace):
     to_ungroup = set(args.to_ungroup)
     to_del = []
     for name, repos in groups.items():
-        remaining = set(repos.split()) - to_ungroup
+        remaining = set(repos) - to_ungroup
         if remaining:
-            groups[name] = ''.join(remaining)
+            groups[name] = list(sorted(remaining))
         else:
             to_del.append(name)
     for name in to_del:
@@ -117,7 +117,7 @@ def f_git_cmd(args: argparse.Namespace):
             if k in repos:
                 chosen[k] = repos[k]
             if k in groups:
-                for r in groups[k].split():
+                for r in groups[k]:
                     chosen[r] = repos[r]
         repos = chosen
     cmds = ['git'] + args.cmd
@@ -232,7 +232,8 @@ def main(argv=None):
     p_group.set_defaults(func=f_group)
 
     p_ungroup = subparsers.add_parser(
-        'ungroup', help='remove group information for repos')
+        'ungroup', help='remove group information for repos',
+        description="Remove group information on repos")
     p_ungroup.add_argument('to_ungroup',
                       nargs='+',
                       choices=utils.get_repos(),
diff --git a/gita/utils.py b/gita/utils.py
index 4fdc267..d14484a 100644
--- a/gita/utils.py
+++ b/gita/utils.py
@@ -43,7 +43,7 @@ def get_repos() -> Dict[str, str]:
 
 
 @lru_cache()
-def get_groups() -> Dict[str, str]:
+def get_groups() -> Dict[str, List[str]]:
     """
     Return a `dict` of group name to repo names.
     """
@@ -98,7 +98,6 @@ def rename_repo(repos: Dict[str, str], repo: str, new_name: str):
     write_to_repo_file(repos, 'w')
 
 
-# TODO: combine these 2 write apis
 def write_to_repo_file(repos: Dict[str, str], mode: str):
     """
     """
@@ -109,15 +108,14 @@ def write_to_repo_file(repos: Dict[str, str], mode: str):
         f.write(data)
 
 
-def write_to_groups_file(groups: Dict[str, str], mode: str):
+def write_to_groups_file(groups: Dict[str, List[str]], mode: str):
     """
 
     """
-    data = ''.join(f'{group}: {repos}\n' for group, repos in groups.items())
     fname = get_config_fname('groups.yml')
     os.makedirs(os.path.dirname(fname), exist_ok=True)
     with open(fname, mode) as f:
-        f.write(data)
+        yaml.dump(groups, f, default_flow_style=None)
 
 
 def add_repos(repos: Dict[str, str], new_paths: List[str]):
diff --git a/setup.py b/setup.py
index 257b038..e6e3984 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@
 setup(
     name='gita',
     packages=['gita'],
-    version='0.10.8',
+    version='0.10.9',
     license='MIT',
     description='Manage multiple git repos',
     long_description=long_description,
@@ -32,6 +32,7 @@
         "Topic :: Utilities",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
     ],
     include_package_data=True,
 )
diff --git a/tests/conftest.py b/tests/conftest.py
index 90d0bab..b3e59ed 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,12 +1,18 @@
-import os
+from pathlib import Path
 from unittest.mock import MagicMock
 
-TEST_DIR = os.path.abspath(os.path.dirname(__file__))
-PATH_FNAME = os.path.join(TEST_DIR, 'mock_path_file')
-PATH_FNAME_EMPTY = os.path.join(TEST_DIR, 'empty_path_file')
-PATH_FNAME_CLASH = os.path.join(TEST_DIR, 'clash_path_file')
+TEST_DIR = Path(__file__).parents[0]
 
 
+def fullpath(fname: str):
+    return str(TEST_DIR / fname)
+
+
+PATH_FNAME = fullpath('mock_path_file')
+PATH_FNAME_EMPTY = fullpath('empty_path_file')
+PATH_FNAME_CLASH = fullpath('clash_path_file')
+GROUP_FNAME = fullpath('mock_group_file')
+
 def async_mock():
     """
     Mock an async function. The calling arguments are saved in a MagicMock.
diff --git a/tests/mock_group_file b/tests/mock_group_file
new file mode 100644
index 0000000..32f0a64
--- /dev/null
+++ b/tests/mock_group_file
@@ -0,0 +1,2 @@
+xx: [a, b]
+yy: [a, c, d]
diff --git a/tests/test_main.py b/tests/test_main.py
index e66ee89..1946352 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -5,7 +5,10 @@
 
 from gita import __main__
 from gita import utils
-from conftest import PATH_FNAME, PATH_FNAME_EMPTY, PATH_FNAME_CLASH, async_mock
+from conftest import (
+    PATH_FNAME, PATH_FNAME_EMPTY, PATH_FNAME_CLASH, GROUP_FNAME,
+    async_mock
+)
 
 
 class TestLsLl:
@@ -128,6 +131,34 @@ def test_superman(mock_run, _, input):
     mock_run.assert_called_once_with(expected_cmds, cwd='path7')
 
 
+@pytest.mark.parametrize('input, expected', [
+    ('a', {'xx': ['b'], 'yy': ['c', 'd']}),
+    ("c", {'xx': ['a', 'b'], 'yy': ['a', 'd']}),
+    ("a b", {'yy': ['c', 'd']}),
+])
+@patch('gita.utils.get_repos', return_value={'a': '', 'b': '', 'c': '', 'd': ''})
+@patch('gita.utils.get_config_fname', return_value=GROUP_FNAME)
+@patch('gita.utils.write_to_groups_file')
+def test_ungroup(mock_write, _, __, input, expected):
+    utils.get_groups.cache_clear()
+    args = ['ungroup'] + shlex.split(input)
+    __main__.main(args)
+    mock_write.assert_called_once_with(expected, 'w')
+
+
+@patch('gita.utils.is_git', return_value=True)
+@patch('gita.utils.get_config_fname', return_value=PATH_FNAME)
+@patch('gita.utils.rename_repo')
+def test_rename(mock_rename, _, __):
+    utils.get_repos.cache_clear()
+    args = ['rename', 'repo1', 'abc']
+    __main__.main(args)
+    mock_rename.assert_called_once_with(
+        {'repo1': '/a/bcd/repo1', 'repo2': '/e/fgh/repo2',
+            'xxx': '/a/b/c/repo3'},
+        'repo1', 'abc')
+
+
 @patch('os.path.isfile', return_value=False)
 def test_info(mock_isfile, capfd):
     __main__.f_info(None)
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 2cd2518..3128041 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -3,7 +3,9 @@
 from unittest.mock import patch, mock_open
 
 from gita import utils, info
-from conftest import PATH_FNAME, PATH_FNAME_EMPTY, PATH_FNAME_CLASH
+from conftest import (
+    PATH_FNAME, PATH_FNAME_EMPTY, PATH_FNAME_CLASH, GROUP_FNAME,
+)
 
 
 @pytest.mark.parametrize('test_input, diff_return, expected', [
@@ -43,8 +45,17 @@ def test_describe(test_input, diff_return, expected, monkeypatch):
 def test_get_repos(mock_path_fname, _, path_fname, expected):
     mock_path_fname.return_value = path_fname
     utils.get_repos.cache_clear()
-    repos = utils.get_repos()
-    assert repos == expected
+    assert utils.get_repos() == expected
+
+
+@pytest.mark.parametrize('group_fname, expected', [
+    (GROUP_FNAME, {'xx': ['a', 'b'], 'yy': ['a', 'c', 'd']}),
+])
+@patch('gita.utils.get_config_fname')
+def test_get_groups(mock_group_fname, group_fname, expected):
+    mock_group_fname.return_value = group_fname
+    utils.get_groups.cache_clear()
+    assert utils.get_groups() == expected
 
 
 @patch('os.path.isfile', return_value=True)