Add tests for combine_expressions()

Signed-off-by: Philippe Ombredanne <[email protected]>

Author: pombredanne

tests/test_license_expression.py

@@ -44,6 +44,7 @@
 from license_expression import TOKEN_WITH
 from license_expression import build_licensing
 from license_expression import build_spdx_licensing
+from license_expression import combine_expressions
 from license_expression import get_license_index
 
 
@@ -2370,3 +2371,20 @@ def test_get_license_key_info_vendored(self):
             expected = json.load(f)
         result = get_license_index()
         assert result == expected
+
+
+class CombineExpressionTest(TestCase):
+
+    def test_combine_expressions_with_empty_input(self):
+        assert combine_expressions(None) == None
+        assert combine_expressions([]) == None
+
+    def test_combine_expressions_with_regular(self):
+        assert combine_expressions(['mit', 'apache-2.0']) == 'mit AND apache-2.0'
+
+    def test_combine_expressions_with_duplicated_elements(self):
+        assert combine_expressions(['mit', 'apache-2.0', 'mit']) == 'mit AND apache-2.0'
+
+    def test_combine_expressions_with_or_relationship(self):
+        assert combine_expressions(['mit', 'apache-2.0'], 'OR') == 'mit OR apache-2.0'
+