Added more logically equivalent tests #67

Signed-off-by: Chin Yeung Li <tli@nexb.com>

Author: chinyeungli

tests/test_license_expression.py

@@ -707,6 +707,34 @@ def test_dedup_expressions_can_be_simplified_4(self):
         expected = l.parse("gpl AND mit AND (gpl OR mit)")
         assert result == expected
 
+    def test_dedup_expressions_logically_equivalent_1(self):
+        l = Licensing()
+        exp = "(gpl OR mit) AND (mit OR gpl)"
+        result = l.dedup(exp)
+        expected = l.parse("gpl OR mit")
+        assert result == expected
+
+    def test_dedup_expressions_logically_equivalent_2(self):
+        l = Licensing()
+        exp = "(gpl AND mit) AND (mit AND gpl)"
+        result = l.dedup(exp)
+        expected = l.parse("gpl AND mit")
+        assert result == expected
+
+    def test_dedup_expressions_logically_equivalent_3(self):
+        l = Licensing()
+        exp = "(gpl OR mit) OR (mit OR gpl)"
+        result = l.dedup(exp)
+        expected = l.parse("gpl OR mit")
+        assert result == expected
+
+    def test_dedup_expressions_logically_equivalent_4(self):
+        l = Licensing()
+        exp = "(gpl AND mit) OR (mit AND gpl)"
+        result = l.dedup(exp)
+        expected = l.parse("gpl AND mit")
+        assert result == expected
+
     def test_dedup_expressions_multiple_occurrences(self):
         l = Licensing()
         exp = " GPL-2.0 or (mit and LGPL-2.1) or bsd Or GPL-2.0  or (mit and LGPL-2.1)"