diff --git a/tests/test_common.py b/tests/test_common.py
index da2e2a8..b29a5c1 100644
--- a/tests/test_common.py
+++ b/tests/test_common.py
@@ -1,7 +1,7 @@
 import unittest
 
 import six
-from nd2reader.common import parse_version, parse_date
+from nd2reader.common import parse_version, parse_date, _add_to_metadata
 
 
 class TestCommon(unittest.TestCase):
@@ -31,4 +31,19 @@ class TestCommon(unittest.TestCase):
         result = parse_date(textinfo)
         self.assertEqual(result.strftime(date_format), date)
 
+    def test_add_to_meta_simple(self):
+        metadata = {}
+        _add_to_metadata(metadata, 'test', 'value')
+        self.assertDictEqual(metadata, {'test': 'value'})
+
+    def test_add_to_meta_new_list(self):
+        metadata = {'test': 'value1'}
+        _add_to_metadata(metadata, 'test', 'value2')
+        self.assertDictEqual(metadata, {'test': ['value1', 'value2']})
+
+    def test_add_to_meta_existing_list(self):
+        metadata = {'test': ['value1', 'value2']}
+        _add_to_metadata(metadata, 'test', 'value3')
+        self.assertDictEqual(metadata, {'test': ['value1', 'value2', 'value3']})
+
 
diff --git a/tests/test_raw_metadata.py b/tests/test_raw_metadata.py
new file mode 100644
index 0000000..9bb436b
--- /dev/null
+++ b/tests/test_raw_metadata.py
@@ -0,0 +1,18 @@
+import unittest
+from nd2reader.raw_metadata import RawMetadata
+
+
+class TestRawMetadata(unittest.TestCase):
+    def setUp(self):
+        self.metadata = RawMetadata(None, None)
+
+    def test_parse_roi_shape(self):
+        self.assertEqual(self.metadata._parse_roi_shape(3), 'rectangle')
+        self.assertEqual(self.metadata._parse_roi_shape(9), 'circle')
+        self.assertIsNone(self.metadata._parse_roi_shape(-1))
+
+    def test_parse_roi_type(self):
+        self.assertEqual(self.metadata._parse_roi_type(3), 'reference')
+        self.assertEqual(self.metadata._parse_roi_type(2), 'background')
+        self.assertEqual(self.metadata._parse_roi_type(4), 'stimulation')
+        self.assertIsNone(self.metadata._parse_roi_type(-1))