Fix test_ultratb (particularly recursion-related tests)

IPython/core/tests/test_ultratb.py

@@ -1,466 +1,439
 # encoding: utf-8
 """Tests for IPython.core.ultratb
 """
 import io
 import logging
 import sys
 import os.path
 from textwrap import dedent
 import traceback
 import unittest
-from unittest import mock
 
-import IPython.core.ultratb as ultratb
-from IPython.core.ultratb import ColorTB, VerboseTB, find_recursion
+from IPython.core.ultratb import ColorTB, VerboseTB
 
 
 from IPython.testing import tools as tt
 from IPython.testing.decorators import onlyif_unicode_paths
 from IPython.utils.syspathcontext import prepended_to_syspath
 from IPython.utils.tempdir import TemporaryDirectory
 
 file_1 = """1
 2
 3
 def f():
   1/0
 """
 
 file_2 = """def f():
   1/0
 """
 
 
 def recursionlimit(frames):
     """
     decorator to set the recursion limit temporarily
     """
 
     def inner(test_function):
         def wrapper(*args, **kwargs):
-            _orig_rec_limit = ultratb._FRAME_RECURSION_LIMIT
-            ultratb._FRAME_RECURSION_LIMIT = 50
-
             rl = sys.getrecursionlimit()
             sys.setrecursionlimit(frames)
             try:
                 return test_function(*args, **kwargs)
             finally:
                 sys.setrecursionlimit(rl)
-                ultratb._FRAME_RECURSION_LIMIT = _orig_rec_limit
 
         return wrapper
 
     return inner
 
 
 class ChangedPyFileTest(unittest.TestCase):
     def test_changing_py_file(self):
         """Traceback produced if the line where the error occurred is missing?
         
         https://github.com/ipython/ipython/issues/1456
         """
         with TemporaryDirectory() as td:
             fname = os.path.join(td, "foo.py")
             with open(fname, "w") as f:
                 f.write(file_1)
             
             with prepended_to_syspath(td):
                 ip.run_cell("import foo")
             
             with tt.AssertPrints("ZeroDivisionError"):
                 ip.run_cell("foo.f()")
             
             # Make the file shorter, so the line of the error is missing.
             with open(fname, "w") as f:
                 f.write(file_2)
             
             # For some reason, this was failing on the *second* call after
             # changing the file, so we call f() twice.
             with tt.AssertNotPrints("Internal Python error", channel='stderr'):
                 with tt.AssertPrints("ZeroDivisionError"):
                     ip.run_cell("foo.f()")
                 with tt.AssertPrints("ZeroDivisionError"):
                     ip.run_cell("foo.f()")
 
 iso_8859_5_file = u'''# coding: iso-8859-5
 
 def fail():
     """дбИЖ"""
     1/0     # дбИЖ
 '''
 
 class NonAsciiTest(unittest.TestCase):
     @onlyif_unicode_paths
     def test_nonascii_path(self):
         # Non-ascii directory name as well.
         with TemporaryDirectory(suffix=u'é') as td:
             fname = os.path.join(td, u"fooé.py")
             with open(fname, "w") as f:
                 f.write(file_1)
             
             with prepended_to_syspath(td):
                 ip.run_cell("import foo")
             
             with tt.AssertPrints("ZeroDivisionError"):
                 ip.run_cell("foo.f()")
     
     def test_iso8859_5(self):
         with TemporaryDirectory() as td:
             fname = os.path.join(td, 'dfghjkl.py')
 
             with io.open(fname, 'w', encoding='iso-8859-5') as f:
                 f.write(iso_8859_5_file)
             
             with prepended_to_syspath(td):
                 ip.run_cell("from dfghjkl import fail")
             
             with tt.AssertPrints("ZeroDivisionError"):
                 with tt.AssertPrints(u'дбИЖ', suppress=False):
                     ip.run_cell('fail()')
     
     def test_nonascii_msg(self):
         cell = u"raise Exception('é')"
         expected = u"Exception('é')"
         ip.run_cell("%xmode plain")
         with tt.AssertPrints(expected):
             ip.run_cell(cell)
 
         ip.run_cell("%xmode verbose")
         with tt.AssertPrints(expected):
             ip.run_cell(cell)
 
         ip.run_cell("%xmode context")
         with tt.AssertPrints(expected):
             ip.run_cell(cell)
 
         ip.run_cell("%xmode minimal")
         with tt.AssertPrints(u"Exception: é"):
             ip.run_cell(cell)
 
         # Put this back into Context mode for later tests.
         ip.run_cell("%xmode context")
 
 class NestedGenExprTestCase(unittest.TestCase):
     """
     Regression test for the following issues:
     https://github.com/ipython/ipython/issues/8293
     https://github.com/ipython/ipython/issues/8205
     """
     def test_nested_genexpr(self):
         code = dedent(
             """\
             class SpecificException(Exception):
                 pass
 
             def foo(x):
                 raise SpecificException("Success!")
 
             sum(sum(foo(x) for _ in [0]) for x in [0])
             """
         )
         with tt.AssertPrints('SpecificException: Success!', suppress=False):
             ip.run_cell(code)
 
 
 indentationerror_file = """if True:
 zoon()
 """
 
 class IndentationErrorTest(unittest.TestCase):
     def test_indentationerror_shows_line(self):
         # See issue gh-2398
         with tt.AssertPrints("IndentationError"):
             with tt.AssertPrints("zoon()", suppress=False):
                 ip.run_cell(indentationerror_file)
         
         with TemporaryDirectory() as td:
             fname = os.path.join(td, "foo.py")
             with open(fname, "w") as f:
                 f.write(indentationerror_file)
             
             with tt.AssertPrints("IndentationError"):
                 with tt.AssertPrints("zoon()", suppress=False):
                     ip.magic('run %s' % fname)
 
 se_file_1 = """1
 2
 7/
 """
 
 se_file_2 = """7/
 """
 
 class SyntaxErrorTest(unittest.TestCase):
     def test_syntaxerror_without_lineno(self):
         with tt.AssertNotPrints("TypeError"):
             with tt.AssertPrints("line unknown"):
                 ip.run_cell("raise SyntaxError()")
 
     def test_syntaxerror_no_stacktrace_at_compile_time(self):
         syntax_error_at_compile_time = """
 def foo():
     ..
 """
         with tt.AssertPrints("SyntaxError"):
             ip.run_cell(syntax_error_at_compile_time)
 
         with tt.AssertNotPrints("foo()"):
             ip.run_cell(syntax_error_at_compile_time)
 
     def test_syntaxerror_stacktrace_when_running_compiled_code(self):
         syntax_error_at_runtime = """
 def foo():
     eval("..")
 
 def bar():
     foo()
 
 bar()
 """
         with tt.AssertPrints("SyntaxError"):
             ip.run_cell(syntax_error_at_runtime)
         # Assert syntax error during runtime generate stacktrace
         with tt.AssertPrints(["foo()", "bar()"]):
             ip.run_cell(syntax_error_at_runtime)
         del ip.user_ns['bar']
         del ip.user_ns['foo']
 
     def test_changing_py_file(self):
         with TemporaryDirectory() as td:
             fname = os.path.join(td, "foo.py")
             with open(fname, 'w') as f:
                 f.write(se_file_1)
 
             with tt.AssertPrints(["7/", "SyntaxError"]):
                 ip.magic("run " + fname)
 
             # Modify the file
             with open(fname, 'w') as f:
                 f.write(se_file_2)
 
             # The SyntaxError should point to the correct line
             with tt.AssertPrints(["7/", "SyntaxError"]):
                 ip.magic("run " + fname)
 
     def test_non_syntaxerror(self):
         # SyntaxTB may be called with an error other than a SyntaxError
         # See e.g. gh-4361
         try:
             raise ValueError('QWERTY')
         except ValueError:
             with tt.AssertPrints('QWERTY'):
                 ip.showsyntaxerror()
 
 
 class MemoryErrorTest(unittest.TestCase):
     def test_memoryerror(self):
         memoryerror_code = "(" * 200 + ")" * 200
         with tt.AssertPrints("MemoryError"):
             ip.run_cell(memoryerror_code)
 
 
 class Python3ChainedExceptionsTest(unittest.TestCase):
     DIRECT_CAUSE_ERROR_CODE = """
 try:
     x = 1 + 2
     print(not_defined_here)
 except Exception as e:
     x += 55
     x - 1
     y = {}
     raise KeyError('uh') from e
     """
 
     EXCEPTION_DURING_HANDLING_CODE = """
 try:
     x = 1 + 2
     print(not_defined_here)
 except Exception as e:
     x += 55
     x - 1
     y = {}
     raise KeyError('uh')
     """
 
     SUPPRESS_CHAINING_CODE = """
 try:
     1/0
 except Exception:
     raise ValueError("Yikes") from None
     """
 
     def test_direct_cause_error(self):
         with tt.AssertPrints(["KeyError", "NameError", "direct cause"]):
             ip.run_cell(self.DIRECT_CAUSE_ERROR_CODE)
 
     def test_exception_during_handling_error(self):
         with tt.AssertPrints(["KeyError", "NameError", "During handling"]):
             ip.run_cell(self.EXCEPTION_DURING_HANDLING_CODE)
 
     def test_suppress_exception_chaining(self):
         with tt.AssertNotPrints("ZeroDivisionError"), \
              tt.AssertPrints("ValueError", suppress=False):
             ip.run_cell(self.SUPPRESS_CHAINING_CODE)
 
     def test_plain_direct_cause_error(self):
         with tt.AssertPrints(["KeyError", "NameError", "direct cause"]):
             ip.run_cell("%xmode Plain")
             ip.run_cell(self.DIRECT_CAUSE_ERROR_CODE)
             ip.run_cell("%xmode Verbose")
 
     def test_plain_exception_during_handling_error(self):
         with tt.AssertPrints(["KeyError", "NameError", "During handling"]):
             ip.run_cell("%xmode Plain")
             ip.run_cell(self.EXCEPTION_DURING_HANDLING_CODE)
             ip.run_cell("%xmode Verbose")
 
     def test_plain_suppress_exception_chaining(self):
         with tt.AssertNotPrints("ZeroDivisionError"), \
              tt.AssertPrints("ValueError", suppress=False):
             ip.run_cell("%xmode Plain")
             ip.run_cell(self.SUPPRESS_CHAINING_CODE)
             ip.run_cell("%xmode Verbose")
 
 
 class RecursionTest(unittest.TestCase):
     DEFINITIONS = """
 def non_recurs():
     1/0
 
 def r1():
     r1()
 
 def r3a():
     r3b()
 
 def r3b():
     r3c()
 
 def r3c():
     r3a()
 
 def r3o1():
     r3a()
 
 def r3o2():
     r3o1()
 """
     def setUp(self):
         ip.run_cell(self.DEFINITIONS)
 
     def test_no_recursion(self):
-        with tt.AssertNotPrints("frames repeated"):
+        with tt.AssertNotPrints("skipping similar frames"):
             ip.run_cell("non_recurs()")
 
     @recursionlimit(150)
     def test_recursion_one_frame(self):
-        with tt.AssertPrints("1 frames repeated"):
+        with tt.AssertPrints("[... skipping similar frames: r1 at line 5 (95 times)]"):
             ip.run_cell("r1()")
 
     @recursionlimit(150)
     def test_recursion_three_frames(self):
-        with tt.AssertPrints("3 frames repeated"):
+        with tt.AssertPrints(
+            "[... skipping similar frames: "
+            "r3a at line 8 (29 times), "
+            "r3b at line 11 (29 times), "
+            "r3c at line 14 (29 times)]"
+        ):
             ip.run_cell("r3o2()")
 
-    @recursionlimit(150)
-    def test_find_recursion(self):
-        captured = []
-        def capture_exc(*args, **kwargs):
-            captured.append(sys.exc_info())
-        with mock.patch.object(ip, 'showtraceback', capture_exc):
-            ip.run_cell("r3o2()")
-
-        self.assertEqual(len(captured), 1)
-        etype, evalue, tb = captured[0]
-        self.assertIn("recursion", str(evalue))
-
-        records = ip.InteractiveTB.get_records(tb, 3, ip.InteractiveTB.tb_offset)
-        for r in records[:10]:
-            print(r[1:4])
-
-        # The outermost frames should be:
-        # 0: the 'cell' that was running when the exception came up
-        # 1: r3o2()
-        # 2: r3o1()
-        # 3: r3a()
-        # Then repeating r3b, r3c, r3a
-        last_unique, repeat_length = find_recursion(etype, evalue, records)
-        self.assertEqual(last_unique, 2)
-        self.assertEqual(repeat_length, 3)
-
 
 #----------------------------------------------------------------------------
 
 # module testing (minimal)
 def test_handlers():
     def spam(c, d_e):
         (d, e) = d_e
         x = c + d
         y = c * d
         foo(x, y)
 
     def foo(a, b, bar=1):
         eggs(a, b + bar)
 
     def eggs(f, g, z=globals()):
         h = f + g
         i = f - g
         return h / i
 
     buff = io.StringIO()
 
     buff.write('')
     buff.write('*** Before ***')
     try:
         buff.write(spam(1, (2, 3)))
     except:
         traceback.print_exc(file=buff)
 
     handler = ColorTB(ostream=buff)
     buff.write('*** ColorTB ***')
     try:
         buff.write(spam(1, (2, 3)))
     except:
         handler(*sys.exc_info())
     buff.write('')
 
     handler = VerboseTB(ostream=buff)
     buff.write('*** VerboseTB ***')
     try:
         buff.write(spam(1, (2, 3)))
     except:
         handler(*sys.exc_info())
     buff.write('')
 
 from IPython.testing.decorators import skipif
 
 class TokenizeFailureTest(unittest.TestCase):
     """Tests related to https://github.com/ipython/ipython/issues/6864."""
 
     # that appear to test that we are handling an exception that can be thrown
     # by the tokenizer due to a bug that seem to have been fixed in 3.8, though
     # I'm unsure if other sequences can make it raise this error. Let's just
     # skip in 3.8 for now
     @skipif(sys.version_info > (3,8))
     def testLogging(self):
         message = "An unexpected error occurred while tokenizing input"
         cell = 'raise ValueError("""a\nb""")'
 
         stream = io.StringIO()
         handler = logging.StreamHandler(stream)
         logger = logging.getLogger()
         loglevel = logger.level
         logger.addHandler(handler)
         self.addCleanup(lambda: logger.removeHandler(handler))
         self.addCleanup(lambda: logger.setLevel(loglevel))
 
         logger.setLevel(logging.INFO)
         with tt.AssertNotPrints(message):
             ip.run_cell(cell)
         self.assertNotIn(message, stream.getvalue())
 
         logger.setLevel(logging.DEBUG)
         with tt.AssertNotPrints(message):
             ip.run_cell(cell)
         self.assertIn(message, stream.getvalue())