diff --git a/gitinspector/extensions.py b/gitinspector/extensions.py
index 4d1f53b..374e543 100644
--- a/gitinspector/extensions.py
+++ b/gitinspector/extensions.py
@@ -18,7 +18,7 @@
 # along with gitinspector. If not, see <http://www.gnu.org/licenses/>.
 
 
-DEFAULT_EXTENSIONS = ["java", "c", "cc", "cpp", "h", "hh", "hpp", "py", "glsl", "rb", "js", "sql"]
+DEFAULT_EXTENSIONS = ["java", "c", "cc", "cpp", "h", "hh", "hpp", "py", "glsl", "rb", "js", "sql", "go"]
 
 __extensions__ = DEFAULT_EXTENSIONS
 __located_extensions__ = set()
diff --git a/tests/test_changes.py b/tests/test_changes.py
index 784eaec..593fa4d 100644
--- a/tests/test_changes.py
+++ b/tests/test_changes.py
@@ -94,4 +94,22 @@ class TestCommitClass(unittest.TestCase):
         self.assertEqual(expected_date, commit.date)
         self.assertEqual(expected_sha, commit.sha)
         self.assertEqual(expected_author, commit.author)
-        self.assertEqual(expected_email, commit.email)
\ No newline at end of file
+        self.assertEqual(expected_email, commit.email)
+
+    def test_get_author_and_email(self):
+        expected_author = 'JP White'
+        expected_email = 'jpwhite3@gmail.com'
+        actual_author, actual_email = changes.Commit.get_author_and_email(FAKE_COMMIT_STRING)
+        self.assertEqual(expected_author, actual_author)
+        self.assertEqual(expected_email, actual_email)
+
+    def test_is_commit_line(self):
+        result = changes.Commit.is_commit_line(FAKE_COMMIT_STRING)
+        self.assertTrue(result)
+
+    def test_add_filediff(self):
+        commit = changes.Commit(FAKE_COMMIT_STRING)
+        commit.add_filediff(1)
+        expected = [1]
+        actual = commit.get_filediffs()
+        self.assertEqual(expected, actual)
diff --git a/tests/test_config.py b/tests/test_config.py
new file mode 100644
index 0000000..5260866
--- /dev/null
+++ b/tests/test_config.py
@@ -0,0 +1,49 @@
+import unittest
+from gitinspector import config
+
+
+class TestConfig(unittest.TestCase):
+
+    def test_GitConfig_init(self):
+        expected_run = 'run'
+        expected_repo = 'repo'
+        expected_global_only = False
+        test_config = config.GitConfig(expected_run, expected_repo)
+        self.assertEqual(expected_run, test_config.run)
+        self.assertEqual(expected_repo, test_config.repo)
+        self.assertEqual(expected_global_only, test_config.global_only)
+
+    def test_read_git_config_unknown_variable(self):
+        expected_result = ''
+        test_config = config.GitConfig('arbitrary', '.')
+        actual_result = test_config.__read_git_config__('unknown')
+        self.assertEqual(expected_result, actual_result)
+
+    def test_read_git_config(self):
+        expected_result = '1'
+        test_config = config.GitConfig('arbitrary', '.')
+        actual_result = test_config.__read_git_config__('arbitrary')
+        self.assertEqual(expected_result, actual_result)
+
+    def test_read_git_config_string(self):
+        expected_result = (True, '1')
+        test_config = config.GitConfig('arbitrary', '.')
+        actual_result = test_config.__read_git_config_string__('arbitrary')
+        self.assertEqual(expected_result, actual_result)
+
+    def test_read_git_config_string_unknown(self):
+        expected_result = (False, None)
+        test_config = config.GitConfig('arbitrary', '.')
+        actual_result = test_config.__read_git_config_string__('unknown')
+        self.assertEqual(expected_result, actual_result)
+
+    def test_read(self):
+        class Dummy():
+            pass
+        test_config = config.GitConfig(Dummy(), '.')
+
+        with self.assertRaises(AttributeError):
+            self.assertFalse(test_config.run.hard)
+
+        test_config.read()
+        self.assertFalse(test_config.run.hard)
diff --git a/tests/test_extensions.py b/tests/test_extensions.py
new file mode 100644
index 0000000..3b30fa6
--- /dev/null
+++ b/tests/test_extensions.py
@@ -0,0 +1,27 @@
+import unittest
+from gitinspector import extensions
+
+
+class TestExtensions(unittest.TestCase):
+
+    def test_001_extensions_get(self):
+        expected = extensions.DEFAULT_EXTENSIONS
+        actual = extensions.get()
+        self.assertEqual(expected, actual)
+
+    def test_002_extensions_define(self):
+        expected = 'txt,md'
+        extensions.define(expected)
+        actual = extensions.get()
+        self.assertEqual(expected.split(","), actual)
+
+    def test_003_add_located(self):
+        expected = set('*')
+        extensions.add_located('')
+        actual = extensions.get_located()
+        self.assertEqual(expected, actual)
+
+        expected = set(['ext', '*'])
+        extensions.add_located('ext')
+        actual = extensions.get_located()
+        self.assertEqual(expected, actual)