Add Xfail test on 3.9.8

See https://bugs.python.org/issue45738 once fixed (or later if not fixed),
we can also catch system error only on the relevant Python versions and
that _should_ be ok, but I want to avoid doing it for now.

IPython/core/tests/test_inputsplitter.py

@@ -1,638 +1,640 b''
 # -*- coding: utf-8 -*-
 """Tests for the inputsplitter module."""
 
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import unittest
 import sys
 
 from IPython.core import inputsplitter as isp
 from IPython.core.inputtransformer import InputTransformer
 from IPython.core.tests.test_inputtransformer import syntax, syntax_ml
 from IPython.testing import tools as tt
+from IPython.testing.decorators import skipif
 
 #-----------------------------------------------------------------------------
 # Semi-complete examples (also used as tests)
 #-----------------------------------------------------------------------------
 
 # Note: at the bottom, there's a slightly more complete version of this that
 # can be useful during development of code here.
 
 def mini_interactive_loop(input_func):
     """Minimal example of the logic of an interactive interpreter loop.
 
     This serves as an example, and it is used by the test system with a fake
     raw_input that simulates interactive input."""
 
     from IPython.core.inputsplitter import InputSplitter
 
     isp = InputSplitter()
     # In practice, this input loop would be wrapped in an outside loop to read
     # input indefinitely, until some exit/quit command was issued.  Here we
     # only illustrate the basic inner loop.
     while isp.push_accepts_more():
         indent = ' '*isp.get_indent_spaces()
         prompt = '>>> ' + indent
         line = indent + input_func(prompt)
         isp.push(line)
 
     # Here we just return input so we can use it in a test suite, but a real
     # interpreter would instead send it for execution somewhere.
     src = isp.source_reset()
     #print 'Input source was:\n', src  # dbg
     return src
 
 #-----------------------------------------------------------------------------
 # Test utilities, just for local use
 #-----------------------------------------------------------------------------
 
 def assemble(block):
     """Assemble a block into multi-line sub-blocks."""
     return ['\n'.join(sub_block)+'\n' for sub_block in block]
 
 
 def pseudo_input(lines):
     """Return a function that acts like raw_input but feeds the input list."""
     ilines = iter(lines)
     def raw_in(prompt):
         try:
             return next(ilines)
         except StopIteration:
             return ''
     return raw_in
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 def test_spaces():
     tests = [('', 0),
              (' ', 1),
              ('\n', 0),
              (' \n', 1),
              ('x', 0),
              (' x', 1),
              ('  x',2),
              ('    x',4),
              # Note: tabs are counted as a single whitespace!
              ('\tx', 1),
              ('\t x', 2),
              ]
     tt.check_pairs(isp.num_ini_spaces, tests)
 
 
 def test_remove_comments():
     tests = [('text', 'text'),
              ('text # comment', 'text '),
              ('text # comment\n', 'text \n'),
              ('text # comment \n', 'text \n'),
              ('line # c \nline\n','line \nline\n'),
              ('line # c \nline#c2  \nline\nline #c\n\n',
               'line \nline\nline\nline \n\n'),
              ]
     tt.check_pairs(isp.remove_comments, tests)
 
 
 def test_get_input_encoding():
     encoding = isp.get_input_encoding()
     assert isinstance(encoding, str)
     # simple-minded check that at least encoding a simple string works with the
     # encoding we got.
     assert "test".encode(encoding) == b"test"
 
 
 class NoInputEncodingTestCase(unittest.TestCase):
     def setUp(self):
         self.old_stdin = sys.stdin
         class X: pass
         fake_stdin = X()
         sys.stdin = fake_stdin
 
     def test(self):
         # Verify that if sys.stdin has no 'encoding' attribute we do the right
         # thing
         enc = isp.get_input_encoding()
         self.assertEqual(enc, 'ascii')
 
     def tearDown(self):
         sys.stdin = self.old_stdin
 
 
 class InputSplitterTestCase(unittest.TestCase):
     def setUp(self):
         self.isp = isp.InputSplitter()
 
     def test_reset(self):
         isp = self.isp
         isp.push('x=1')
         isp.reset()
         self.assertEqual(isp._buffer, [])
         self.assertEqual(isp.get_indent_spaces(), 0)
         self.assertEqual(isp.source, '')
         self.assertEqual(isp.code, None)
         self.assertEqual(isp._is_complete, False)
 
     def test_source(self):
         self.isp._store('1')
         self.isp._store('2')
         self.assertEqual(self.isp.source, '1\n2\n')
         self.assertEqual(len(self.isp._buffer)>0, True)
         self.assertEqual(self.isp.source_reset(), '1\n2\n')
         self.assertEqual(self.isp._buffer, [])
         self.assertEqual(self.isp.source, '')
 
     def test_indent(self):
         isp = self.isp # shorthand
         isp.push('x=1')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n    x=1')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('y=2\n')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_indent2(self):
         isp = self.isp
         isp.push('if 1:')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('    x=1')
         self.assertEqual(isp.get_indent_spaces(), 4)
         # Blank lines shouldn't change the indent level
         isp.push(' '*2)
         self.assertEqual(isp.get_indent_spaces(), 4)
 
     def test_indent3(self):
         isp = self.isp
         # When a multiline statement contains parens or multiline strings, we
         # shouldn't get confused.
         isp.push("if 1:")
         isp.push("    x = (1+\n    2)")
         self.assertEqual(isp.get_indent_spaces(), 4)
 
     def test_indent4(self):
         isp = self.isp
         # whitespace after ':' should not screw up indent level
         isp.push('if 1: \n    x=1')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('y=2\n')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\t\n    x=1')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('y=2\n')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_dedent_pass(self):
         isp = self.isp # shorthand
         # should NOT cause dedent
         isp.push('if 1:\n    passes = 5')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('if 1:\n     pass')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n     pass   ')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_dedent_break(self):
         isp = self.isp # shorthand
         # should NOT cause dedent
         isp.push('while 1:\n    breaks = 5')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('while 1:\n     break')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('while 1:\n     break   ')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_dedent_continue(self):
         isp = self.isp # shorthand
         # should NOT cause dedent
         isp.push('while 1:\n    continues = 5')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('while 1:\n     continue')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('while 1:\n     continue   ')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_dedent_raise(self):
         isp = self.isp # shorthand
         # should NOT cause dedent
         isp.push('if 1:\n    raised = 4')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('if 1:\n     raise TypeError()')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n     raise')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n     raise      ')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_dedent_return(self):
         isp = self.isp # shorthand
         # should NOT cause dedent
         isp.push('if 1:\n    returning = 4')
         self.assertEqual(isp.get_indent_spaces(), 4)
         isp.push('if 1:\n     return 5 + 493')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n     return')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n     return      ')
         self.assertEqual(isp.get_indent_spaces(), 0)
         isp.push('if 1:\n     return(0)')
         self.assertEqual(isp.get_indent_spaces(), 0)
 
     def test_push(self):
         isp = self.isp
         self.assertEqual(isp.push('x=1'), True)
 
     def test_push2(self):
         isp = self.isp
         self.assertEqual(isp.push('if 1:'), False)
         for line in ['  x=1', '# a comment', '  y=2']:
             print(line)
             self.assertEqual(isp.push(line), True)
 
     def test_push3(self):
         isp = self.isp
         isp.push('if True:')
         isp.push('  a = 1')
         self.assertEqual(isp.push('b = [1,'), False)
 
     def test_push_accepts_more(self):
         isp = self.isp
         isp.push('x=1')
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_push_accepts_more2(self):
         isp = self.isp
         isp.push('if 1:')
         self.assertEqual(isp.push_accepts_more(), True)
         isp.push('  x=1')
         self.assertEqual(isp.push_accepts_more(), True)
         isp.push('')
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_push_accepts_more3(self):
         isp = self.isp
         isp.push("x = (2+\n3)")
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_push_accepts_more4(self):
         isp = self.isp
         # When a multiline statement contains parens or multiline strings, we
         # shouldn't get confused.
         # FIXME: we should be able to better handle de-dents in statements like
         # multiline strings and multiline expressions (continued with \ or
         # parens).  Right now we aren't handling the indentation tracking quite
         # correctly with this, though in practice it may not be too much of a
         # problem.  We'll need to see.
         isp.push("if 1:")
         isp.push("    x = (2+")
         isp.push("    3)")
         self.assertEqual(isp.push_accepts_more(), True)
         isp.push("    y = 3")
         self.assertEqual(isp.push_accepts_more(), True)
         isp.push('')
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_push_accepts_more5(self):
         isp = self.isp
         isp.push('try:')
         isp.push('    a = 5')
         isp.push('except:')
         isp.push('    raise')
         # We want to be able to add an else: block at this point, so it should
         # wait for a blank line.
         self.assertEqual(isp.push_accepts_more(), True)
 
     def test_continuation(self):
         isp = self.isp
         isp.push("import os, \\")
         self.assertEqual(isp.push_accepts_more(), True)
         isp.push("sys")
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_syntax_error(self):
         isp = self.isp
         # Syntax errors immediately produce a 'ready' block, so the invalid
         # Python can be sent to the kernel for evaluation with possible ipython
         # special-syntax conversion.
         isp.push('run foo')
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_unicode(self):
         self.isp.push(u"Pérez")
         self.isp.push(u'\xc3\xa9')
         self.isp.push(u"u'\xc3\xa9'")
 
+    @skipif(sys.version_info[:3] == (3, 9, 8))
     def test_line_continuation(self):
         """ Test issue #2108."""
         isp = self.isp
         # A blank line after a line continuation should not accept more
         isp.push("1 \\\n\n")
         self.assertEqual(isp.push_accepts_more(), False)
         # Whitespace after a \ is a SyntaxError.  The only way to test that
         # here is to test that push doesn't accept more (as with
         # test_syntax_error() above).
         isp.push(r"1 \ ")
         self.assertEqual(isp.push_accepts_more(), False)
         # Even if the line is continuable (c.f. the regular Python
         # interpreter)
         isp.push(r"(1 \ ")
         self.assertEqual(isp.push_accepts_more(), False)
 
     def test_check_complete(self):
         isp = self.isp
         self.assertEqual(isp.check_complete("a = 1"), ('complete', None))
         self.assertEqual(isp.check_complete("for a in range(5):"), ('incomplete', 4))
         self.assertEqual(isp.check_complete("raise = 2"), ('invalid', None))
         self.assertEqual(isp.check_complete("a = [1,\n2,"), ('incomplete', 0))
         self.assertEqual(isp.check_complete("def a():\n x=1\n global x"), ('invalid', None))
 
 class InteractiveLoopTestCase(unittest.TestCase):
     """Tests for an interactive loop like a python shell.
     """
     def check_ns(self, lines, ns):
         """Validate that the given input lines produce the resulting namespace.
 
         Note: the input lines are given exactly as they would be typed in an
         auto-indenting environment, as mini_interactive_loop above already does
         auto-indenting and prepends spaces to the input.
         """
         src = mini_interactive_loop(pseudo_input(lines))
         test_ns = {}
         exec(src, test_ns)
         # We can't check that the provided ns is identical to the test_ns,
         # because Python fills test_ns with extra keys (copyright, etc).  But
         # we can check that the given dict is *contained* in test_ns
         for k,v in ns.items():
             self.assertEqual(test_ns[k], v)
 
     def test_simple(self):
         self.check_ns(['x=1'], dict(x=1))
 
     def test_simple2(self):
         self.check_ns(['if 1:', 'x=2'], dict(x=2))
 
     def test_xy(self):
         self.check_ns(['x=1; y=2'], dict(x=1, y=2))
 
     def test_abc(self):
         self.check_ns(['if 1:','a=1','b=2','c=3'], dict(a=1, b=2, c=3))
 
     def test_multi(self):
         self.check_ns(['x =(1+','1+','2)'], dict(x=4))
 
 
 class IPythonInputTestCase(InputSplitterTestCase):
     """By just creating a new class whose .isp is a different instance, we
     re-run the same test battery on the new input splitter.
 
     In addition, this runs the tests over the syntax and syntax_ml dicts that
     were tested by individual functions, as part of the OO interface.
 
     It also makes some checks on the raw buffer storage.
     """
 
     def setUp(self):
         self.isp = isp.IPythonInputSplitter()
 
     def test_syntax(self):
         """Call all single-line syntax tests from the main object"""
         isp = self.isp
         for example in syntax.values():
             for raw, out_t in example:
                 if raw.startswith(' '):
                     continue
 
                 isp.push(raw+'\n')
                 out_raw = isp.source_raw
                 out = isp.source_reset()
                 self.assertEqual(out.rstrip(), out_t,
                         tt.pair_fail_msg.format("inputsplitter",raw, out_t, out))
                 self.assertEqual(out_raw.rstrip(), raw.rstrip())
 
     def test_syntax_multiline(self):
         isp = self.isp
         for example in syntax_ml.values():
             for line_pairs in example:
                 out_t_parts = []
                 raw_parts = []
                 for lraw, out_t_part in line_pairs:
                     if out_t_part is not None:
                         out_t_parts.append(out_t_part)
 
                     if lraw is not None:
                         isp.push(lraw)
                         raw_parts.append(lraw)
 
                 out_raw = isp.source_raw
                 out = isp.source_reset()
                 out_t = '\n'.join(out_t_parts).rstrip()
                 raw = '\n'.join(raw_parts).rstrip()
                 self.assertEqual(out.rstrip(), out_t)
                 self.assertEqual(out_raw.rstrip(), raw)
 
     def test_syntax_multiline_cell(self):
         isp = self.isp
         for example in syntax_ml.values():
 
             out_t_parts = []
             for line_pairs in example:
                 raw = '\n'.join(r for r, _ in line_pairs if r is not None)
                 out_t = '\n'.join(t for _,t in line_pairs if t is not None)
                 out = isp.transform_cell(raw)
                 # Match ignoring trailing whitespace
                 self.assertEqual(out.rstrip(), out_t.rstrip())
 
     def test_cellmagic_preempt(self):
         isp = self.isp
         for raw, name, line, cell in [
             ("%%cellm a\nIn[1]:", u'cellm', u'a', u'In[1]:'),
             ("%%cellm \nline\n>>> hi", u'cellm', u'', u'line\n>>> hi'),
             (">>> %%cellm \nline\n>>> hi", u'cellm', u'', u'line\nhi'),
             ("%%cellm \n>>> hi", u'cellm', u'', u'>>> hi'),
             ("%%cellm \nline1\nline2", u'cellm', u'', u'line1\nline2'),
             ("%%cellm \nline1\\\\\nline2", u'cellm', u'', u'line1\\\\\nline2'),
         ]:
             expected = "get_ipython().run_cell_magic(%r, %r, %r)" % (
                 name, line, cell
             )
             out = isp.transform_cell(raw)
             self.assertEqual(out.rstrip(), expected.rstrip())
 
     def test_multiline_passthrough(self):
         isp = self.isp
         class CommentTransformer(InputTransformer):
             def __init__(self):
                 self._lines = []
 
             def push(self, line):
                 self._lines.append(line + '#')
 
             def reset(self):
                 text = '\n'.join(self._lines)
                 self._lines = []
                 return text
 
         isp.physical_line_transforms.insert(0, CommentTransformer())
 
         for raw, expected in [
             ("a=5", "a=5#"),
             ("%ls foo", "get_ipython().run_line_magic(%r, %r)" % (u'ls', u'foo#')),
             ("!ls foo\n%ls bar", "get_ipython().system(%r)\nget_ipython().run_line_magic(%r, %r)" % (
                 u'ls foo#', u'ls', u'bar#'
             )),
             ("1\n2\n3\n%ls foo\n4\n5", "1#\n2#\n3#\nget_ipython().run_line_magic(%r, %r)\n4#\n5#" % (u'ls', u'foo#')),
         ]:
             out = isp.transform_cell(raw)
             self.assertEqual(out.rstrip(), expected.rstrip())
 
 #-----------------------------------------------------------------------------
 # Main - use as a script, mostly for developer experiments
 #-----------------------------------------------------------------------------
 
 if __name__ == '__main__':
     # A simple demo for interactive experimentation.  This code will not get
     # picked up by any test suite.
     from IPython.core.inputsplitter import IPythonInputSplitter
 
     # configure here the syntax to use, prompt and whether to autoindent
     #isp, start_prompt = InputSplitter(), '>>> '
     isp, start_prompt = IPythonInputSplitter(), 'In> '
 
     autoindent = True
     #autoindent = False
 
     try:
         while True:
             prompt = start_prompt
             while isp.push_accepts_more():
                 indent = ' '*isp.get_indent_spaces()
                 if autoindent:
                     line = indent + input(prompt+indent)
                 else:
                     line = input(prompt)
                 isp.push(line)
                 prompt = '... '
 
             # Here we just return input so we can use it in a test suite, but a
             # real interpreter would instead send it for execution somewhere.
             #src = isp.source; raise EOFError # dbg
             raw = isp.source_raw
             src = isp.source_reset()
             print('Input source was:\n', src)
             print('Raw source was:\n', raw)
     except EOFError:
         print('Bye')
 
 # Tests for cell magics support
 
 def test_last_blank():
     assert isp.last_blank("") is False
     assert isp.last_blank("abc") is False
     assert isp.last_blank("abc\n") is False
     assert isp.last_blank("abc\na") is False
 
     assert isp.last_blank("\n") is True
     assert isp.last_blank("\n ") is True
     assert isp.last_blank("abc\n ") is True
     assert isp.last_blank("abc\n\n") is True
     assert isp.last_blank("abc\nd\n\n") is True
     assert isp.last_blank("abc\nd\ne\n\n") is True
     assert isp.last_blank("abc \n \n \n\n") is True
 
 
 def test_last_two_blanks():
     assert isp.last_two_blanks("") is False
     assert isp.last_two_blanks("abc") is False
     assert isp.last_two_blanks("abc\n") is False
     assert isp.last_two_blanks("abc\n\na") is False
     assert isp.last_two_blanks("abc\n \n") is False
     assert isp.last_two_blanks("abc\n\n") is False
 
     assert isp.last_two_blanks("\n\n") is True
     assert isp.last_two_blanks("\n\n ") is True
     assert isp.last_two_blanks("\n \n") is True
     assert isp.last_two_blanks("abc\n\n ") is True
     assert isp.last_two_blanks("abc\n\n\n") is True
     assert isp.last_two_blanks("abc\n\n \n") is True
     assert isp.last_two_blanks("abc\n\n \n ") is True
     assert isp.last_two_blanks("abc\n\n \n \n") is True
     assert isp.last_two_blanks("abc\nd\n\n\n") is True
     assert isp.last_two_blanks("abc\nd\ne\nf\n\n\n") is True
 
 
 class CellMagicsCommon(object):
 
     def test_whole_cell(self):
         src = "%%cellm line\nbody\n"
         out = self.sp.transform_cell(src)
         ref = "get_ipython().run_cell_magic('cellm', 'line', 'body')\n"
         assert out == ref
 
     def test_cellmagic_help(self):
         self.sp.push('%%cellm?')
         assert self.sp.push_accepts_more() is False
 
     def tearDown(self):
         self.sp.reset()
 
 
 class CellModeCellMagics(CellMagicsCommon, unittest.TestCase):
     sp = isp.IPythonInputSplitter(line_input_checker=False)
 
     def test_incremental(self):
         sp = self.sp
         sp.push("%%cellm firstline\n")
         assert sp.push_accepts_more() is True  # 1
         sp.push("line2\n")
         assert sp.push_accepts_more() is True  # 2
         sp.push("\n")
         # This should accept a blank line and carry on until the cell is reset
         assert sp.push_accepts_more() is True  # 3
 
     def test_no_strip_coding(self):
         src = '\n'.join([
             '%%writefile foo.py',
             '# coding: utf-8',
             'print(u"üñîçø∂é")',
         ])
         out = self.sp.transform_cell(src)
         assert "# coding: utf-8" in out
 
 
 class LineModeCellMagics(CellMagicsCommon, unittest.TestCase):
     sp = isp.IPythonInputSplitter(line_input_checker=True)
 
     def test_incremental(self):
         sp = self.sp
         sp.push("%%cellm line2\n")
         assert sp.push_accepts_more() is True  # 1
         sp.push("\n")
         # In this case, a blank line should end the cell magic
         assert sp.push_accepts_more() is False  # 2
 
 
 indentation_samples = [
     ('a = 1', 0),
     ('for a in b:', 4),
     ('def f():', 4),
     ('def f(): #comment', 4),
     ('a = ":#not a comment"', 0),
     ('def f():\n    a = 1', 4),
     ('def f():\n    return 1', 0),
     ('for a in b:\n'
      '   if a < 0:'
      '       continue', 3),
     ('a = {', 4),
     ('a = {\n'
      '     1,', 5),
     ('b = """123', 0),
     ('', 0),
     ('def f():\n    pass', 0),
     ('class Bar:\n    def f():\n        pass', 4),
     ('class Bar:\n    def f():\n        raise', 4),
 ]
 
 def test_find_next_indent():
     for code, exp in indentation_samples:
         res = isp.find_next_indent(code)
         msg = "{!r} != {!r} (expected)\n Code: {!r}".format(res, exp, code)
         assert res == exp, msg

IPython/core/tests/test_inputtransformer2.py

@@ -1,359 +1,387 b''
 """Tests for the token-based transformers in IPython.core.inputtransformer2
 
 Line-based transformers are the simpler ones; token-based transformers are
 more complex. See test_inputtransformer2_line for tests for line-based
 transformations.
 """
 import string
+import sys
+from textwrap import dedent
 
-from IPython.core import inputtransformer2 as ipt2
-from IPython.core.inputtransformer2 import make_tokens_by_line, _find_assign_op
+import pytest
 
-from textwrap import dedent
+from IPython.core import inputtransformer2 as ipt2
+from IPython.core.inputtransformer2 import _find_assign_op, make_tokens_by_line
+from IPython.testing.decorators import skip_iptest_but_not_pytest
 
 MULTILINE_MAGIC = ("""\
 a = f()
 %foo \\
 bar
 g()
 """.splitlines(keepends=True), (2, 0), """\
 a = f()
 get_ipython().run_line_magic('foo', ' bar')
 g()
 """.splitlines(keepends=True))
 
 INDENTED_MAGIC = ("""\
 for a in range(5):
     %ls
 """.splitlines(keepends=True), (2, 4), """\
 for a in range(5):
     get_ipython().run_line_magic('ls', '')
 """.splitlines(keepends=True))
 
 CRLF_MAGIC = ([
     "a = f()\n",
     "%ls\r\n",
     "g()\n"
 ], (2, 0), [
     "a = f()\n",
     "get_ipython().run_line_magic('ls', '')\n",
     "g()\n"
 ])
 
 MULTILINE_MAGIC_ASSIGN = ("""\
 a = f()
 b = %foo \\
   bar
 g()
 """.splitlines(keepends=True), (2, 4), """\
 a = f()
 b = get_ipython().run_line_magic('foo', '   bar')
 g()
 """.splitlines(keepends=True))
 
 MULTILINE_SYSTEM_ASSIGN = ("""\
 a = f()
 b = !foo \\
   bar
 g()
 """.splitlines(keepends=True), (2, 4), """\
 a = f()
 b = get_ipython().getoutput('foo    bar')
 g()
 """.splitlines(keepends=True))
 
 #####
 
 MULTILINE_SYSTEM_ASSIGN_AFTER_DEDENT = ("""\
 def test():
   for i in range(1):
     print(i)
   res =! ls
 """.splitlines(keepends=True), (4, 7), '''\
 def test():
   for i in range(1):
     print(i)
   res =get_ipython().getoutput(\' ls\')
 '''.splitlines(keepends=True))
 
 ######
 
 AUTOCALL_QUOTE = (
     [",f 1 2 3\n"], (1, 0),
     ['f("1", "2", "3")\n']
 )
 
 AUTOCALL_QUOTE2 = (
     [";f 1 2 3\n"], (1, 0),
     ['f("1 2 3")\n']
 )
 
 AUTOCALL_PAREN = (
     ["/f 1 2 3\n"], (1, 0),
     ['f(1, 2, 3)\n']
 )
 
 SIMPLE_HELP = (
     ["foo?\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo', 'foo')\n"]
 )
 
 DETAILED_HELP = (
     ["foo??\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo2', 'foo')\n"]
 )
 
 MAGIC_HELP = (
     ["%foo?\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo', '%foo')\n"]
 )
 
 HELP_IN_EXPR = (
     ["a = b + c?\n"], (1, 0),
     ["get_ipython().set_next_input('a = b + c');"
      "get_ipython().run_line_magic('pinfo', 'c')\n"]
 )
 
 HELP_CONTINUED_LINE = ("""\
 a = \\
 zip?
 """.splitlines(keepends=True), (1, 0),
 [r"get_ipython().set_next_input('a = \\\nzip');get_ipython().run_line_magic('pinfo', 'zip')" + "\n"]
 )
 
 HELP_MULTILINE = ("""\
 (a,
 b) = zip?
 """.splitlines(keepends=True), (1, 0),
 [r"get_ipython().set_next_input('(a,\nb) = zip');get_ipython().run_line_magic('pinfo', 'zip')" + "\n"]
 )
 
 HELP_UNICODE = (
     ["π.foo?\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo', 'π.foo')\n"]
 )
 
 
 def null_cleanup_transformer(lines):
     """
     A cleanup transform that returns an empty list.
     """
     return []
 
 def check_make_token_by_line_never_ends_empty():
     """
     Check that not sequence of single or double characters ends up leading to en empty list of tokens
     """
     from string import printable
     for c in printable:
         assert make_tokens_by_line(c)[-1] != []
         for k in printable:
             assert make_tokens_by_line(c + k)[-1] != []
 
 
 def check_find(transformer, case, match=True):
     sample, expected_start, _  = case
     tbl = make_tokens_by_line(sample)
     res = transformer.find(tbl)
     if match:
         # start_line is stored 0-indexed, expected values are 1-indexed
         assert (res.start_line + 1, res.start_col) == expected_start
         return res
     else:
         assert res is None
 
 def check_transform(transformer_cls, case):
     lines, start, expected = case
     transformer = transformer_cls(start)
     assert transformer.transform(lines) == expected
 
 def test_continued_line():
     lines = MULTILINE_MAGIC_ASSIGN[0]
     assert ipt2.find_end_of_continued_line(lines, 1) == 2
 
     assert ipt2.assemble_continued_line(lines, (1, 5), 2) == "foo    bar"
 
 def test_find_assign_magic():
     check_find(ipt2.MagicAssign, MULTILINE_MAGIC_ASSIGN)
     check_find(ipt2.MagicAssign, MULTILINE_SYSTEM_ASSIGN, match=False)
     check_find(ipt2.MagicAssign, MULTILINE_SYSTEM_ASSIGN_AFTER_DEDENT, match=False)
 
 def test_transform_assign_magic():
     check_transform(ipt2.MagicAssign, MULTILINE_MAGIC_ASSIGN)
 
 def test_find_assign_system():
     check_find(ipt2.SystemAssign, MULTILINE_SYSTEM_ASSIGN)
     check_find(ipt2.SystemAssign, MULTILINE_SYSTEM_ASSIGN_AFTER_DEDENT)
     check_find(ipt2.SystemAssign, (["a =  !ls\n"], (1, 5), None))
     check_find(ipt2.SystemAssign, (["a=!ls\n"], (1, 2), None))
     check_find(ipt2.SystemAssign, MULTILINE_MAGIC_ASSIGN, match=False)
 
 def test_transform_assign_system():
     check_transform(ipt2.SystemAssign, MULTILINE_SYSTEM_ASSIGN)
     check_transform(ipt2.SystemAssign, MULTILINE_SYSTEM_ASSIGN_AFTER_DEDENT)
 
 def test_find_magic_escape():
     check_find(ipt2.EscapedCommand, MULTILINE_MAGIC)
     check_find(ipt2.EscapedCommand, INDENTED_MAGIC)
     check_find(ipt2.EscapedCommand, MULTILINE_MAGIC_ASSIGN, match=False)
 
 def test_transform_magic_escape():
     check_transform(ipt2.EscapedCommand, MULTILINE_MAGIC)
     check_transform(ipt2.EscapedCommand, INDENTED_MAGIC)
     check_transform(ipt2.EscapedCommand, CRLF_MAGIC)
 
 def test_find_autocalls():
     for case in [AUTOCALL_QUOTE, AUTOCALL_QUOTE2, AUTOCALL_PAREN]:
         print("Testing %r" % case[0])
         check_find(ipt2.EscapedCommand, case)
 
 def test_transform_autocall():
     for case in [AUTOCALL_QUOTE, AUTOCALL_QUOTE2, AUTOCALL_PAREN]:
         print("Testing %r" % case[0])
         check_transform(ipt2.EscapedCommand, case)
 
 def test_find_help():
     for case in [SIMPLE_HELP, DETAILED_HELP, MAGIC_HELP, HELP_IN_EXPR]:
         check_find(ipt2.HelpEnd, case)
 
     tf = check_find(ipt2.HelpEnd, HELP_CONTINUED_LINE)
     assert tf.q_line == 1
     assert tf.q_col == 3
 
     tf = check_find(ipt2.HelpEnd, HELP_MULTILINE)
     assert tf.q_line == 1
     assert tf.q_col == 8
 
     # ? in a comment does not trigger help
     check_find(ipt2.HelpEnd, (["foo # bar?\n"], None, None), match=False)
     # Nor in a string
     check_find(ipt2.HelpEnd, (["foo = '''bar?\n"], None, None), match=False)
 
 def test_transform_help():
     tf = ipt2.HelpEnd((1, 0), (1, 9))
     assert tf.transform(HELP_IN_EXPR[0]) == HELP_IN_EXPR[2]
 
     tf = ipt2.HelpEnd((1, 0), (2, 3))
     assert tf.transform(HELP_CONTINUED_LINE[0]) == HELP_CONTINUED_LINE[2]
 
     tf = ipt2.HelpEnd((1, 0), (2, 8))
     assert tf.transform(HELP_MULTILINE[0]) == HELP_MULTILINE[2]
 
     tf = ipt2.HelpEnd((1, 0), (1, 0))
     assert tf.transform(HELP_UNICODE[0]) == HELP_UNICODE[2]
 
 def test_find_assign_op_dedent():
     """
     be careful that empty token like dedent are not counted as parens
     """
     class Tk:
         def __init__(self, s):
             self.string = s
 
     assert _find_assign_op([Tk(s) for s in ("", "a", "=", "b")]) == 2
     assert (
         _find_assign_op([Tk(s) for s in ("", "(", "a", "=", "b", ")", "=", "5")]) == 6
     )
 
 
+examples = [
+    pytest.param("a = 1", "complete", None),
+    pytest.param("for a in range(5):", "incomplete", 4),
+    pytest.param("for a in range(5):\n    if a > 0:", "incomplete", 8),
+    pytest.param("raise = 2", "invalid", None),
+    pytest.param("a = [1,\n2,", "incomplete", 0),
+    pytest.param("(\n))", "incomplete", 0),
+    pytest.param("\\\r\n", "incomplete", 0),
+    pytest.param("a = '''\n   hi", "incomplete", 3),
+    pytest.param("def a():\n x=1\n global x", "invalid", None),
+    pytest.param(
+        "a \\ ",
+        "invalid",
+        None,
+        marks=pytest.mark.xfail(
+            reason="Bug in python 3.9.8 – bpo 45738",
+            condition=sys.version_info[:3] == (3, 9, 8),
+            raises=SystemError,
+            strict=True,
+        ),
+    ),  # Nothing allowed after backslash,
+    pytest.param("1\\\n+2", "complete", None),
+]
+
+
+@skip_iptest_but_not_pytest
[e-mail]("code, expected, number", examples)
+def test_check_complete_param(code, expected, number):
+    cc = ipt2.TransformerManager().check_complete
+    assert cc(code) == (expected, number)
+
+
+@skip_iptest_but_not_pytest
[e-mail](
+    reason="Bug in python 3.9.8 – bpo 45738",
+    condition=sys.version_info[:3] == (3, 9, 8),
+)
 def test_check_complete():
     cc = ipt2.TransformerManager().check_complete
-    assert cc("a = 1") == ("complete", None)
-    assert cc("for a in range(5):") == ("incomplete", 4)
-    assert cc("for a in range(5):\n    if a > 0:") == ("incomplete", 8)
-    assert cc("raise = 2") == ("invalid", None)
-    assert cc("a = [1,\n2,") == ("incomplete", 0)
-    assert cc("(\n))") == ("incomplete", 0)
-    assert cc("\\\r\n") == ("incomplete", 0)
-    assert cc("a = '''\n   hi") == ("incomplete", 3)
-    assert cc("def a():\n x=1\n global x") == ("invalid", None)
-    assert cc("a \\ ") == ("invalid", None)  # Nothing allowed after backslash
-    assert cc("1\\\n+2") == ("complete", None)
-    assert cc("exit") == ("complete", None)
 
     example = dedent("""
         if True:
             a=1""" )
 
     assert cc(example) == ("incomplete", 4)
     assert cc(example + "\n") == ("complete", None)
     assert cc(example + "\n    ") == ("complete", None)
 
     # no need to loop on all the letters/numbers.
     short = '12abAB'+string.printable[62:]
     for c in short:
         # test does not raise:
         cc(c)
         for k in short:
             cc(c+k)
 
     assert cc("def f():\n  x=0\n  \\\n  ") == ("incomplete", 2)
 
 
 def test_check_complete_II():
     """
     Test that multiple line strings are properly handled.
 
     Separate test function for convenience
 
     """
     cc = ipt2.TransformerManager().check_complete
     assert cc('''def foo():\n    """''') == ("incomplete", 4)
 
 
 def test_check_complete_invalidates_sunken_brackets():
     """
     Test that a single line with more closing brackets than the opening ones is
     interpreted as invalid
     """
     cc = ipt2.TransformerManager().check_complete
     assert cc(")") == ("invalid", None)
     assert cc("]") == ("invalid", None)
     assert cc("}") == ("invalid", None)
     assert cc(")(") == ("invalid", None)
     assert cc("][") == ("invalid", None)
     assert cc("}{") == ("invalid", None)
     assert cc("]()(") == ("invalid", None)
     assert cc("())(") == ("invalid", None)
     assert cc(")[](") == ("invalid", None)
     assert cc("()](") == ("invalid", None)
 
 
 def test_null_cleanup_transformer():
     manager = ipt2.TransformerManager()
     manager.cleanup_transforms.insert(0, null_cleanup_transformer)
     assert manager.transform_cell("") == ""
 
 
 
 
 def test_side_effects_I():
     count = 0
     def counter(lines):
         nonlocal count
         count += 1
         return lines
 
     counter.has_side_effects = True
 
     manager = ipt2.TransformerManager()
     manager.cleanup_transforms.insert(0, counter)
     assert manager.check_complete("a=1\n") == ('complete', None)
     assert count == 0
 
 
 
 
 def test_side_effects_II():
     count = 0
     def counter(lines):
         nonlocal count
         count += 1
         return lines
 
     counter.has_side_effects = True
 
     manager = ipt2.TransformerManager()
     manager.line_transforms.insert(0, counter)
     assert manager.check_complete("b=1\n") == ('complete', None)
     assert count == 0