[otConverters_test] add tests for _LazyList

Tests/ttLib/tables/otConverters_test.py

@@ -350,6 +350,75 @@ class AATLookupTest(unittest.TestCase):
         ])
 
 
+class LazyListTest(unittest.TestCase):
+
+    def test_slice(self):
+        ll = otConverters._LazyList([10, 11, 12, 13])
+        sl = ll[:]
+
+        self.assertIsNot(sl, ll)
+        self.assertIsInstance(sl, list)
+        self.assertEqual([10, 11, 12, 13], sl)
+
+        self.assertEqual([11, 12], ll[1:3])
+
+    def test_getitem(self):
+        count = 2
+        reader = OTTableReader(b"\x00\xFE\xFF\x00\x00\x00", offset=1)
+        converter = otConverters.UInt8("UInt8", 0, None, None)
+        recordSize = converter.staticSize
+        l = otConverters._LazyList()
+        l.reader = reader
+        l.pos = l.reader.pos
+        l.font = None
+        l.conv = converter
+        l.recordSize = recordSize
+        l.extend(otConverters._MissingItem([i]) for i in range(count))
+        reader.advance(count * recordSize)
+
+        self.assertEqual(l[0], 254)
+        self.assertEqual(l[1], 255)
+
+    def test_add_both_LazyList(self):
+        ll1 = otConverters._LazyList([1])
+        ll2 = otConverters._LazyList([2])
+
+        l3 = ll1 + ll2
+
+        self.assertIsInstance(l3, list)
+        self.assertEqual([1, 2], l3)
+
+    def test_add_LazyList_and_list(self):
+        ll1 = otConverters._LazyList([1])
+        l2 = [2]
+
+        l3 = ll1 + l2
+
+        self.assertIsInstance(l3, list)
+        self.assertEqual([1, 2], l3)
+
+    def test_add_not_implemented(self):
+        with self.assertRaises(TypeError):
+            otConverters._LazyList() + 0
+        with self.assertRaises(TypeError):
+            otConverters._LazyList() + tuple()
+
+    def test_radd_list_and_LazyList(self):
+        l1 = [1]
+        ll2 = otConverters._LazyList([2])
+
+        l3 = l1 + ll2
+
+        self.assertIsInstance(l3, list)
+        self.assertEqual([1, 2], l3)
+
+    def test_radd_not_implemented(self):
+        with self.assertRaises(TypeError):
+            0 + otConverters._LazyList()
+        with self.assertRaises(TypeError):
+            tuple() + otConverters._LazyList()
+
+
 if __name__ == "__main__":
     import sys
     sys.exit(unittest.main())