[consutil][test] Add unit tests for consutil clear command (sonic-net#1274)

* [consutil] Add UT for consutil clear command
* Fix test cases

Signed-off-by: Jing Kan [email protected]

Author: Blueve

tests/console_test.py

@@ -578,3 +578,64 @@ def test_connect_success(self):
         print(sys.stderr, result.output)
         assert result.exit_code == 0
         assert result.output == "Successful connection to line [1]\nPress ^A ^X to disconnect\n"
+
+class TestConsutilClear(object):
+    @classmethod
+    def setup_class(cls):
+        print("SETUP")
+
+    @mock.patch('consutil.lib.SysInfoProvider.list_console_ttys', mock.MagicMock(return_value=["/dev/ttyUSB1"]))
+    @mock.patch('consutil.lib.SysInfoProvider.init_device_prefix', mock.MagicMock(return_value=None))
+    @mock.patch('os.geteuid', mock.MagicMock(return_value=1))
+    def test_clear_without_root(self):
+        runner = CliRunner()
+        db = Db()
+
+        result = runner.invoke(consutil.consutil.commands["clear"], ['1'], obj=db)
+        print(result.exit_code)
+        print(sys.stderr, result.output)
+        assert result.exit_code == 2
+        assert "Root privileges are required for this operation" in result.output
+
+    @mock.patch('consutil.lib.SysInfoProvider.list_console_ttys', mock.MagicMock(return_value=["/dev/ttyUSB1"]))
+    @mock.patch('consutil.lib.SysInfoProvider.init_device_prefix', mock.MagicMock(return_value=None))
+    @mock.patch('os.geteuid', mock.MagicMock(return_value=0))
+    def test_clear_line_not_found(self):
+        runner = CliRunner()
+        db = Db()
+
+        result = runner.invoke(consutil.consutil.commands["clear"], ['2'], obj=db)
+        print(result.exit_code)
+        print(sys.stderr, result.output)
+        assert result.exit_code == 3
+        assert "Target [2] does not exist" in result.output
+
+    @mock.patch('consutil.lib.SysInfoProvider.list_console_ttys', mock.MagicMock(return_value=["/dev/ttyUSB1"]))
+    @mock.patch('consutil.lib.SysInfoProvider.init_device_prefix', mock.MagicMock(return_value=None))
+    @mock.patch('os.geteuid', mock.MagicMock(return_value=0))
+    @mock.patch('consutil.lib.ConsolePortInfo.clear_session', mock.MagicMock(return_value=False))
+    def test_clear_idle(self):
+        runner = CliRunner()
+        db = Db()
+        db.cfgdb.set_entry("CONSOLE_PORT", 1, { "remote_device" : "switch1", "baud_rate" : "9600" })
+
+        result = runner.invoke(consutil.consutil.commands["clear"], ['1'], obj=db)
+        print(result.exit_code)
+        print(sys.stderr, result.output)
+        assert result.exit_code == 0
+        assert "No process is connected to line 1" in result.output
+
+    @mock.patch('consutil.lib.SysInfoProvider.list_console_ttys', mock.MagicMock(return_value=["/dev/ttyUSB1"]))
+    @mock.patch('consutil.lib.SysInfoProvider.init_device_prefix', mock.MagicMock(return_value=None))
+    @mock.patch('os.geteuid', mock.MagicMock(return_value=0))
+    @mock.patch('consutil.lib.ConsolePortInfo.clear_session', mock.MagicMock(return_value=True))
+    def test_clear_success(self):
+        runner = CliRunner()
+        db = Db()
+        db.cfgdb.set_entry("CONSOLE_PORT", 1, { "remote_device" : "switch1", "baud_rate" : "9600" })
+
+        result = runner.invoke(consutil.consutil.commands["clear"], ['1'], obj=db)
+        print(result.exit_code)
+        print(sys.stderr, result.output)
+        assert result.exit_code == 0
+        assert result.output == ""