Move GetDeviceTest from adb's test_device.py to adb package.

This test actually belongs with the adb python wrapper, since it's not
affected by changes to adb itself.

Bug: http://b/64260633
Test: python test.py
Change-Id: Ia70a5529e30d91ea6232c65c9d50b2dabd07b925

python-packages/adb/test.py

@@ -0,0 +1,80 @@
+#
+# Copyright (C) 2017 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import os
+import unittest
+import mock
+
+import adb
+
+class GetDeviceTest(unittest.TestCase):
+    def setUp(self):
+        self.android_serial = os.getenv('ANDROID_SERIAL')
+        if 'ANDROID_SERIAL' in os.environ:
+            del os.environ['ANDROID_SERIAL']
+
+    def tearDown(self):
+        if self.android_serial is not None:
+            os.environ['ANDROID_SERIAL'] = self.android_serial
+        else:
+            if 'ANDROID_SERIAL' in os.environ:
+                del os.environ['ANDROID_SERIAL']
+
+    @mock.patch('adb.device.get_devices')
+    def test_explicit(self, mock_get_devices):
+        mock_get_devices.return_value = ['foo', 'bar']
+        device = adb.get_device('foo')
+        self.assertEqual(device.serial, 'foo')
+
+    @mock.patch('adb.device.get_devices')
+    def test_from_env(self, mock_get_devices):
+        mock_get_devices.return_value = ['foo', 'bar']
+        os.environ['ANDROID_SERIAL'] = 'foo'
+        device = adb.get_device()
+        self.assertEqual(device.serial, 'foo')
+
+    @mock.patch('adb.device.get_devices')
+    def test_arg_beats_env(self, mock_get_devices):
+        mock_get_devices.return_value = ['foo', 'bar']
+        os.environ['ANDROID_SERIAL'] = 'bar'
+        device = adb.get_device('foo')
+        self.assertEqual(device.serial, 'foo')
+
+    @mock.patch('adb.device.get_devices')
+    def test_no_such_device(self, mock_get_devices):
+        mock_get_devices.return_value = ['foo', 'bar']
+        self.assertRaises(adb.DeviceNotFoundError, adb.get_device, ['baz'])
+
+        os.environ['ANDROID_SERIAL'] = 'baz'
+        self.assertRaises(adb.DeviceNotFoundError, adb.get_device)
+
+    @mock.patch('adb.device.get_devices')
+    def test_unique_device(self, mock_get_devices):
+        mock_get_devices.return_value = ['foo']
+        device = adb.get_device()
+        self.assertEqual(device.serial, 'foo')
+
+    @mock.patch('adb.device.get_devices')
+    def test_no_unique_device(self, mock_get_devices):
+        mock_get_devices.return_value = ['foo', 'bar']
+        self.assertRaises(adb.NoUniqueDeviceError, adb.get_device)
+
+
+def main():
+    suite = unittest.TestLoader().loadTestsFromName(__name__)
+    unittest.TextTestRunner(verbosity=3).run(suite)
+
+if __name__ == '__main__':
+    main()