1 files changed, 144 insertions, 3 deletions
diff --git a/tests/languages/docker_test.py b/tests/languages/docker_test.py
index 3bed4bf..01b5e27 100644
--- a/tests/languages/docker_test.py
+++ b/tests/languages/docker_test.py
@@ -1,14 +1,155 @@
+import builtins
+import json
+import ntpath
+import os.path
+import posixpath
 from unittest import mock
 
+import pytest
+
 from pre_commit.languages import docker
 
 
 def test_docker_fallback_user():
     def invalid_attribute():
         raise AttributeError
+
     with mock.patch.multiple(
-        'os', create=True,
-        getuid=invalid_attribute,
-        getgid=invalid_attribute,
+            'os', create=True,
+            getuid=invalid_attribute,
+            getgid=invalid_attribute,
     ):
         assert docker.get_docker_user() == ()
+
+
+def test_in_docker_no_file():
+    with mock.patch.object(builtins, 'open', side_effect=FileNotFoundError):
+        assert docker._is_in_docker() is False
+
+
+def _mock_open(data):
+    return mock.patch.object(
+        builtins,
+        'open',
+        new_callable=mock.mock_open,
+        read_data=data,
+    )
+
+
+def test_in_docker_docker_in_file():
+    docker_cgroup_example = b'''\
+12:hugetlb:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+11:blkio:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+10:freezer:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+9:cpu,cpuacct:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+8:pids:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+7:rdma:/
+6:net_cls,net_prio:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+5:cpuset:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+4:devices:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+3:memory:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+2:perf_event:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+1:name=systemd:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
+0::/system.slice/containerd.service
+'''  # noqa: E501
+    with _mock_open(docker_cgroup_example):
+        assert docker._is_in_docker() is True
+
+
+def test_in_docker_docker_not_in_file():
+    non_docker_cgroup_example = b'''\
+12:perf_event:/
+11:hugetlb:/
+10:devices:/
+9:blkio:/
+8:rdma:/
+7:cpuset:/
+6:cpu,cpuacct:/
+5:freezer:/
+4:memory:/
+3:pids:/
+2:net_cls,net_prio:/
+1:name=systemd:/init.scope
+0::/init.scope
+'''
+    with _mock_open(non_docker_cgroup_example):
+        assert docker._is_in_docker() is False
+
+
+def test_get_docker_path_not_in_docker_returns_same():
+    with mock.patch.object(docker, '_is_in_docker', return_value=False):
+        assert docker._get_docker_path('abc') == 'abc'
+
+
+@pytest.fixture
+def in_docker():
+    with mock.patch.object(docker, '_is_in_docker', return_value=True):
+        yield
+
+
+def _linux_commonpath():
+    return mock.patch.object(os.path, 'commonpath', posixpath.commonpath)
+
+
+def _nt_commonpath():
+    return mock.patch.object(os.path, 'commonpath', ntpath.commonpath)
+
+
+def _docker_output(out):
+    ret = (0, out, b'')
+    return mock.patch.object(docker, 'cmd_output_b', return_value=ret)
+
+
+def test_get_docker_path_in_docker_no_binds_same_path(in_docker):
+    docker_out = json.dumps([{'Mounts': []}]).encode()
+
+    with _docker_output(docker_out):
+        assert docker._get_docker_path('abc') == 'abc'
+
+
+def test_get_docker_path_in_docker_binds_path_equal(in_docker):
+    binds_list = [{'Source': '/opt/my_code', 'Destination': '/project'}]
+    docker_out = json.dumps([{'Mounts': binds_list}]).encode()
+
+    with _linux_commonpath(), _docker_output(docker_out):
+        assert docker._get_docker_path('/project') == '/opt/my_code'
+
+
+def test_get_docker_path_in_docker_binds_path_complex(in_docker):
+    binds_list = [{'Source': '/opt/my_code', 'Destination': '/project'}]
+    docker_out = json.dumps([{'Mounts': binds_list}]).encode()
+
+    with _linux_commonpath(), _docker_output(docker_out):
+        path = '/project/test/something'
+        assert docker._get_docker_path(path) == '/opt/my_code/test/something'
+
+
+def test_get_docker_path_in_docker_no_substring(in_docker):
+    binds_list = [{'Source': '/opt/my_code', 'Destination': '/project'}]
+    docker_out = json.dumps([{'Mounts': binds_list}]).encode()
+
+    with _linux_commonpath(), _docker_output(docker_out):
+        path = '/projectSuffix/test/something'
+        assert docker._get_docker_path(path) == path
+
+
+def test_get_docker_path_in_docker_binds_path_many_binds(in_docker):
+    binds_list = [
+        {'Source': '/something_random', 'Destination': '/not-related'},
+        {'Source': '/opt/my_code', 'Destination': '/project'},
+        {'Source': '/something-random-2', 'Destination': '/not-related-2'},
+    ]
+    docker_out = json.dumps([{'Mounts': binds_list}]).encode()
+
+    with _linux_commonpath(), _docker_output(docker_out):
+        assert docker._get_docker_path('/project') == '/opt/my_code'
+
+
+def test_get_docker_path_in_docker_windows(in_docker):
+    binds_list = [{'Source': r'c:\users\user', 'Destination': r'c:\folder'}]
+    docker_out = json.dumps([{'Mounts': binds_list}]).encode()
+
+    with _nt_commonpath(), _docker_output(docker_out):
+        path = r'c:\folder\test\something'
+        expected = r'c:\users\user\test\something'
+        assert docker._get_docker_path(path) == expected