def test_append_and_prepend(self):
c = ListUpdateClause('s', [1, 2, 3, 4, 5, 6], previous=[3, 4])
c._analyze()
c.set_context_id(0)
self.assertIsNone(c._assignments)
self.assertEqual(c._append, [5, 6])
self.assertEqual(c._prepend, [1, 2])
self.assertEqual(c.get_context_size(), 2)
self.assertEqual(str(c), '"s" = %(0)s + "s", "s" = "s" + %(1)s')
ctx = {}
c.update_context(ctx)
self.assertEqual(ctx, {'0': [1, 2], '1': [5, 6]})
def test_prepend(self):
c = ListUpdateClause("s", [1, 2, 3, 4], previous=[3, 4])
c._analyze()
c.set_context_id(0)
self.assertIsNone(c._assignments)
self.assertIsNone(c._append)
self.assertEqual(c._prepend, [1, 2])
self.assertEqual(c.get_context_size(), 1)
self.assertEqual(str(c), '"s" = %(0)s + "s"')
ctx = {}
c.update_context(ctx)
self.assertEqual(ctx, {"0": [1, 2]})
def test_update_from_different_list(self):
c = ListUpdateClause('s', [1, 2, 3], previous=[3, 2, 1])
c._analyze()
c.set_context_id(0)
self.assertEqual(c._assignments, [1, 2, 3])
self.assertIsNone(c._append)
self.assertIsNone(c._prepend)
self.assertEqual(c.get_context_size(), 1)
self.assertEqual(str(c), '"s" = %(0)s')
ctx = {}
c.update_context(ctx)
self.assertEqual(ctx, {'0': [1, 2, 3]})
def test_update_from_empty(self):
c = ListUpdateClause("s", [1, 2, 3], previous=[])
c._analyze()
c.set_context_id(0)
self.assertEqual(c._assignments, [1, 2, 3])
self.assertIsNone(c._append)
self.assertIsNone(c._prepend)
self.assertEqual(c.get_context_size(), 1)
self.assertEqual(str(c), '"s" = %(0)s')
ctx = {}
c.update_context(ctx)
self.assertEqual(ctx, {"0": [1, 2, 3]})
def test_shrinking_list_update(self):
""" tests that updating to a smaller list results in an insert statement """
c = ListUpdateClause('s', [1, 2, 3], previous=[1, 2, 3, 4])
c._analyze()
c.set_context_id(0)
self.assertEqual(c._assignments, [1, 2, 3])
self.assertIsNone(c._append)
self.assertIsNone(c._prepend)
self.assertEqual(c.get_context_size(), 1)
self.assertEqual(str(c), '"s" = %(0)s')
ctx = {}
c.update_context(ctx)
self.assertEqual(ctx, {'0': [1, 2, 3]})