diff --git a/tests/test_stats.py b/tests/test_stats.py
new file mode 100644
index 0000000..e06b9eb
--- /dev/null
+++ b/tests/test_stats.py
@@ -0,0 +1,113 @@
+# -*- coding: utf-8 -*-
+
+
+import logging
+import os
+import time
+import uuid
+from testfixtures import log_capture
+from .utils import ANY, CustomResponse, NamedTemporaryFile, TestCase, mock
+
+from wakatime.compat import u
+from wakatime.constants import SUCCESS
+from wakatime.main import execute
+from wakatime.packages import requests
+from wakatime.stats import number_lines_in_file
+
+
+class StatsTestCase(TestCase):
+    patch_these = [
+        'wakatime.packages.requests.adapters.HTTPAdapter.send',
+        'wakatime.session_cache.SessionCache.save',
+        'wakatime.session_cache.SessionCache.delete',
+        ['wakatime.session_cache.SessionCache.get', requests.session],
+        ['wakatime.session_cache.SessionCache.connect', None],
+    ]
+
+    @log_capture()
+    def test_guess_lexer_using_filename_analyse_text_exception(self, logs):
+        logging.disable(logging.NOTSET)
+        self.patched['wakatime.packages.requests.adapters.HTTPAdapter.send'].return_value = CustomResponse()
+
+        with NamedTemporaryFile() as fh:
+            with mock.patch('wakatime.offlinequeue.Queue._get_db_file') as mock_db_file:
+                mock_db_file.return_value = fh.name
+
+                mock_analyse = mock.MagicMock()
+                mock_analyse.analyse_text.side_effect = Exception('foobar')
+                with mock.patch('wakatime.stats.custom_pygments_guess_lexer_for_filename') as mock_lexer:
+                    mock_lexer.return_value = mock_analyse
+
+                    entity = os.path.realpath('tests/samples/codefiles/python.py')
+                    args = ['--file', entity, '--key', str(uuid.uuid4()), '--config', 'tests/samples/configs/good_config.cfg', '--time', u(int(time.time()))]
+                    retval = execute(args)
+                    self.assertEquals(retval, SUCCESS)
+
+                    self.assertNothingPrinted()
+                    self.assertNothingLogged(logs)
+
+                    heartbeat = {
+                        'entity': entity,
+                        'language': ANY,
+                        'lines': ANY,
+                        'project': ANY,
+                        'branch': ANY,
+                        'time': ANY,
+                        'type': 'file',
+                        'is_write': ANY,
+                        'user_agent': ANY,
+                        'dependencies': ANY,
+                    }
+                    self.assertHeartbeatSent(heartbeat)
+
+    @log_capture()
+    def test_guess_lexer_using_filename_analyse_text_exception_and_logs_error_when_debugging(self, logs):
+        logging.disable(logging.NOTSET)
+        self.patched['wakatime.packages.requests.adapters.HTTPAdapter.send'].return_value = CustomResponse()
+
+        with NamedTemporaryFile() as fh:
+            with mock.patch('wakatime.offlinequeue.Queue._get_db_file') as mock_db_file:
+                mock_db_file.return_value = fh.name
+
+                mock_analyse = mock.MagicMock()
+                mock_analyse.analyse_text.side_effect = Exception('foobar')
+                with mock.patch('wakatime.stats.custom_pygments_guess_lexer_for_filename') as mock_lexer:
+                    mock_lexer.return_value = mock_analyse
+
+                    entity = os.path.realpath('tests/samples/codefiles/python.py')
+                    args = ['--file', entity, '--key', str(uuid.uuid4()), '--config', 'tests/samples/configs/good_config.cfg', '--time', u(int(time.time())), '--verbose']
+                    retval = execute(args)
+                    self.assertEquals(retval, SUCCESS)
+
+                    self.assertNothingPrinted()
+                    actual = self.getLogOutput(logs)
+                    expected = 'Exception: foobar'
+                    self.assertIn(expected, actual)
+
+                    heartbeat = {
+                        'entity': entity,
+                        'language': ANY,
+                        'lines': ANY,
+                        'project': ANY,
+                        'branch': ANY,
+                        'time': ANY,
+                        'type': 'file',
+                        'is_write': ANY,
+                        'user_agent': ANY,
+                        'dependencies': ANY,
+                    }
+                    self.assertHeartbeatSent(heartbeat)
+
+    @log_capture()
+    def test_number_lines_in_file_getsize_os_error(self, logs):
+        logging.disable(logging.NOTSET)
+
+        with mock.patch('wakatime.stats.os.path.getsize') as mock_getsize:
+            mock_getsize.side_effect = os.error('')
+
+            entity = os.path.realpath('tests/samples/codefiles/java.java')
+            result = number_lines_in_file(entity)
+            self.assertEquals(result, 22)
+
+            self.assertNothingPrinted()
+            self.assertNothingLogged(logs)