1import dis
2from test.support import import_module
3import unittest
4
5_opcode = import_module("_opcode")
6
7class OpcodeTests(unittest.TestCase):
8
9    def test_stack_effect(self):
10        self.assertEqual(_opcode.stack_effect(dis.opmap['POP_TOP']), -1)
11        self.assertEqual(_opcode.stack_effect(dis.opmap['DUP_TOP_TWO']), 2)
12        self.assertEqual(_opcode.stack_effect(dis.opmap['BUILD_SLICE'], 0), -1)
13        self.assertEqual(_opcode.stack_effect(dis.opmap['BUILD_SLICE'], 1), -1)
14        self.assertEqual(_opcode.stack_effect(dis.opmap['BUILD_SLICE'], 3), -2)
15        self.assertRaises(ValueError, _opcode.stack_effect, 30000)
16        self.assertRaises(ValueError, _opcode.stack_effect, dis.opmap['BUILD_SLICE'])
17        self.assertRaises(ValueError, _opcode.stack_effect, dis.opmap['POP_TOP'], 0)
18
19if __name__ == "__main__":
20    unittest.main()
21