test_javascript.py

   1 from unittest import TestCase
   2 import javascript
   3 from io import StringIO
   4 from unittest.mock import patch
   5 from math import inf, ldexp, copysign
   6
   7 class Test(TestCase):
   8     def test_identifier_escaped(self):
   9         for [code, name] in (
  10             (r'ab\u0063de', 'abcde'),
  11             (r'\u005Cu123\u0034', '\\u1234'),
  12         ):
  13             with self.subTest(code):
  14                 [code] = javascript.parse(StringIO(code))
  15                 self.assertEqual(code, ('identifier', name))
  16         for code in ('ab\\y0033z', 'ab\\', '\\u123\\u0034'):
  17             with self.subTest(code):
  18                 parser = javascript.parse(StringIO(code))
  19                 self.assertRaises(Exception, next, parser, None)
  20
  21     def test_token_buffering(self):
  22         with patch.object(javascript.Parser, 'BUFSIZE', 10):
  23             [code] = javascript.parse(StringIO('abcdefg >>>= x'))
  24         self.assertEqual(code,
  25             ( '>>>=', ('identifier', 'abcdefg'), ('identifier', 'x') ))
  26
  27     def test_rounding(self):
  28         for [code, rounded] in (
  29             ('0.24703''28229''20623''27208e-323', 0),
  30             ('0.24703''28229''20623''27209e-323', ldexp(2**-52, -1022)),
  31             ('24703''28229''20623''27208e-343', 0),
  32             ('24703''28229''20623''27209e-343', ldexp(2**-52, -1022)),
  33             ('0.17976''93134''86231''58079e+309', ldexp(1 - 2**-53, +1024)),
  34             ('0.17976''93134''86231''58080e+309', inf),
  35             ('17976''93134''86231''58079e+289', ldexp(1 - 2**-53, +1024)),
  36             ('17976''93134''86231''58080e+289', inf),
  37             (f'{2**52 + 0}.5', 2**52),
  38             (f'{2**52 + 1}.5', 2**52 + 2),
  39             (hex( 2**1024 - 2**(1024 - 53) + (0b10 << (1024 - 55)) ), inf),
  40             (hex( 2**1024 - 2**(1024 - 53) + (0b01 << (1024 - 55)) ),
  41                 ldexp(1 - 2**-53, +1024)),
  42             (hex(2**53 + 0b01), 2**53),
  43             (hex(2**53 + 0b11), 2**53 + 0b100),
  44         ):
  45             with self.subTest(code):
  46                 [code] = javascript.parse(StringIO(code))
  47                 self.assertEqual(code, rounded)
  48                 self.assertEqual(copysign(1, code), copysign(1, rounded))