gh-108303: Move all `pydoc` related test files to new `test.test_pydoc` package (#114506)

1 files changed, 2015 insertions, 0 deletions

diff --git a/Lib/test/test_pydoc/test_pydoc.py b/Lib/test/test_pydoc/test_pydoc.py
new file mode 100644
index 0000000..0dd24e6
--- /dev/null
+++ b/Lib/test/test_pydoc/test_pydoc.py
@@ -0,0 +1,2015 @@
+import datetime
+import os
+import sys
+import contextlib
+import importlib.util
+import inspect
+import pydoc
+import py_compile
+import keyword
+import _pickle
+import pkgutil
+import re
+import stat
+import tempfile
+import test.support
+import time
+import types
+import typing
+import unittest
+import urllib.parse
+import xml.etree
+import xml.etree.ElementTree
+import textwrap
+from io import StringIO
+from collections import namedtuple
+from urllib.request import urlopen, urlcleanup
+from test import support
+from test.support import import_helper
+from test.support import os_helper
+from test.support.script_helper import (assert_python_ok,
+                                        assert_python_failure, spawn_python)
+from test.support import threading_helper
+from test.support import (reap_children, captured_output, captured_stdout,
+                          captured_stderr, is_emscripten, is_wasi,
+                          requires_docstrings, MISSING_C_DOCSTRINGS)
+from test.support.os_helper import (TESTFN, rmtree, unlink)
+from test.test_pydoc import pydoc_mod
+from test.test_pydoc import pydocfodder
+
+
+class nonascii:
+    'Це не латиниця'
+    pass
+
+if test.support.HAVE_DOCSTRINGS:
+    expected_data_docstrings = (
+        'dictionary for instance variables',
+        'list of weak references to the object',
+        ) * 2
+else:
+    expected_data_docstrings = ('', '', '', '')
+
+expected_text_pattern = """
+NAME
+    test.test_pydoc.pydoc_mod - This is a test module for test_pydoc
+%s
+CLASSES
+    builtins.object
+        A
+        B
+        C
+
+    class A(builtins.object)
+     |  Hello and goodbye
+     |
+     |  Methods defined here:
+     |
+     |  __init__()
+     |      Wow, I have no function!
+     |
+     |  ----------------------------------------------------------------------
+     |  Data descriptors defined here:
+     |
+     |  __dict__%s
+     |
+     |  __weakref__%s
+
+    class B(builtins.object)
+     |  Data descriptors defined here:
+     |
+     |  __dict__%s
+     |
+     |  __weakref__%s
+     |
+     |  ----------------------------------------------------------------------
+     |  Data and other attributes defined here:
+     |
+     |  NO_MEANING = 'eggs'
+     |
+     |  __annotations__ = {'NO_MEANING': <class 'str'>}
+
+    class C(builtins.object)
+     |  Methods defined here:
+     |
+     |  get_answer(self)
+     |      Return say_no()
+     |
+     |  is_it_true(self)
+     |      Return self.get_answer()
+     |
+     |  say_no(self)
+     |
+     |  ----------------------------------------------------------------------
+     |  Class methods defined here:
+     |
+     |  __class_getitem__(item)
+     |
+     |  ----------------------------------------------------------------------
+     |  Data descriptors defined here:
+     |
+     |  __dict__
+     |      dictionary for instance variables
+     |
+     |  __weakref__
+     |      list of weak references to the object
+
+FUNCTIONS
+    doc_func()
+        This function solves all of the world's problems:
+        hunger
+        lack of Python
+        war
+
+    nodoc_func()
+
+DATA
+    __xyz__ = 'X, Y and Z'
+    c_alias = test.test_pydoc.pydoc_mod.C[int]
+    list_alias1 = typing.List[int]
+    list_alias2 = list[int]
+    type_union1 = typing.Union[int, str]
+    type_union2 = int | str
+
+VERSION
+    1.2.3.4
+
+AUTHOR
+    Benjamin Peterson
+
+CREDITS
+    Nobody
+
+FILE
+    %s
+""".strip()
+
+expected_text_data_docstrings = tuple('\n     |      ' + s if s else ''
+                                      for s in expected_data_docstrings)
+
+html2text_of_expected = """
+test.test_pydoc.pydoc_mod (version 1.2.3.4)
+This is a test module for test_pydoc
+
+Modules
+    types
+    typing
+
+Classes
+    builtins.object
+    A
+    B
+    C
+
+class A(builtins.object)
+    Hello and goodbye
+
+    Methods defined here:
+        __init__()
+            Wow, I have no function!
+    ----------------------------------------------------------------------
+    Data descriptors defined here:
+        __dict__
+            dictionary for instance variables
+        __weakref__
+            list of weak references to the object
+
+class B(builtins.object)
+    Data descriptors defined here:
+        __dict__
+            dictionary for instance variables
+        __weakref__
+            list of weak references to the object
+    ----------------------------------------------------------------------
+    Data and other attributes defined here:
+        NO_MEANING = 'eggs'
+        __annotations__ = {'NO_MEANING': <class 'str'>}
+
+
+class C(builtins.object)
+    Methods defined here:
+        get_answer(self)
+            Return say_no()
+        is_it_true(self)
+            Return self.get_answer()
+        say_no(self)
+    ----------------------------------------------------------------------
+    Class methods defined here:
+        __class_getitem__(item)
+    ----------------------------------------------------------------------
+    Data descriptors defined here:
+        __dict__
+            dictionary for instance variables
+        __weakref__
+             list of weak references to the object
+
+Functions
+    doc_func()
+        This function solves all of the world's problems:
+        hunger
+        lack of Python
+        war
+    nodoc_func()
+
+Data
+    __xyz__ = 'X, Y and Z'
+    c_alias = test.test_pydoc.pydoc_mod.C[int]
+    list_alias1 = typing.List[int]
+    list_alias2 = list[int]
+    type_union1 = typing.Union[int, str]
+    type_union2 = int | str
+
+Author
+    Benjamin Peterson
+
+Credits
+    Nobody
+"""
+
+expected_html_data_docstrings = tuple(s.replace(' ', '&nbsp;')
+                                      for s in expected_data_docstrings)
+
+# output pattern for missing module
+missing_pattern = '''\
+No Python documentation found for %r.
+Use help() to get the interactive help utility.
+Use help(str) for help on the str class.'''.replace('\n', os.linesep)
+
+# output pattern for module with bad imports
+badimport_pattern = "problem in %s - ModuleNotFoundError: No module named %r"
+
+expected_dynamicattribute_pattern = """
+Help on class DA in module %s:
+
+class DA(builtins.object)
+ |  Data descriptors defined here:
+ |
+ |  __dict__%s
+ |
+ |  __weakref__%s
+ |
+ |  ham
+ |
+ |  ----------------------------------------------------------------------
+ |  Data and other attributes inherited from Meta:
+ |
+ |  ham = 'spam'
+""".strip()
+
+expected_virtualattribute_pattern1 = """
+Help on class Class in module %s:
+
+class Class(builtins.object)
+ |  Data and other attributes inherited from Meta:
+ |
+ |  LIFE = 42
+""".strip()
+
+expected_virtualattribute_pattern2 = """
+Help on class Class1 in module %s:
+
+class Class1(builtins.object)
+ |  Data and other attributes inherited from Meta1:
+ |
+ |  one = 1
+""".strip()
+
+expected_virtualattribute_pattern3 = """
+Help on class Class2 in module %s:
+
+class Class2(Class1)
+ |  Method resolution order:
+ |      Class2
+ |      Class1
+ |      builtins.object
+ |
+ |  Data and other attributes inherited from Meta1:
+ |
+ |  one = 1
+ |
+ |  ----------------------------------------------------------------------
+ |  Data and other attributes inherited from Meta3:
+ |
+ |  three = 3
+ |
+ |  ----------------------------------------------------------------------
+ |  Data and other attributes inherited from Meta2:
+ |
+ |  two = 2
+""".strip()
+
+expected_missingattribute_pattern = """
+Help on class C in module %s:
+
+class C(builtins.object)
+ |  Data and other attributes defined here:
+ |
+ |  here = 'present!'
+""".strip()
+
+def run_pydoc(module_name, *args, **env):
+    """
+    Runs pydoc on the specified module. Returns the stripped
+    output of pydoc.
+    """
+    args = args + (module_name,)
+    # do not write bytecode files to avoid caching errors
+    rc, out, err = assert_python_ok('-B', pydoc.__file__, *args, **env)
+    return out.strip()
+
+def run_pydoc_fail(module_name, *args, **env):
+    """
+    Runs pydoc on the specified module expecting a failure.
+    """
+    args = args + (module_name,)
+    rc, out, err = assert_python_failure('-B', pydoc.__file__, *args, **env)
+    return out.strip()
+
+def get_pydoc_html(module):
+    "Returns pydoc generated output as html"
+    doc = pydoc.HTMLDoc()
+    output = doc.docmodule(module)
+    loc = doc.getdocloc(pydoc_mod) or ""
+    if loc:
+        loc = "<br><a href=\"" + loc + "\">Module Docs</a>"
+    return output.strip(), loc
+
+def clean_text(doc):
+    # clean up the extra text formatting that pydoc performs
+    return re.sub('\b.', '', doc)
+
+def get_pydoc_link(module):
+    "Returns a documentation web link of a module"
+    abspath = os.path.abspath
+    dirname = os.path.dirname
+    basedir = dirname(dirname(dirname(abspath(__file__))))
+    doc = pydoc.TextDoc()
+    loc = doc.getdocloc(module, basedir=basedir)
+    return loc
+
+def get_pydoc_text(module):
+    "Returns pydoc generated output as text"
+    doc = pydoc.TextDoc()
+    loc = doc.getdocloc(pydoc_mod) or ""
+    if loc:
+        loc = "\nMODULE DOCS\n    " + loc + "\n"
+
+    output = doc.docmodule(module)
+    output = clean_text(output)
+    return output.strip(), loc
+
+def get_html_title(text):
+    # Bit of hack, but good enough for test purposes
+    header, _, _ = text.partition("</head>")
+    _, _, title = header.partition("<title>")
+    title, _, _ = title.partition("</title>")
+    return title
+
+
+def html2text(html):
+    """A quick and dirty implementation of html2text.
+
+    Tailored for pydoc tests only.
+    """
+    html = html.replace("<dd>", "\n")
+    html = html.replace("<hr>", "-"*70)
+    html = re.sub("<.*?>", "", html)
+    html = pydoc.replace(html, "&nbsp;", " ", "&gt;", ">", "&lt;", "<")
+    return html
+
+
+class PydocBaseTest(unittest.TestCase):
+
+    def _restricted_walk_packages(self, walk_packages, path=None):
+        """
+        A version of pkgutil.walk_packages() that will restrict itself to
+        a given path.
+        """
+        default_path = path or [os.path.dirname(__file__)]
+        def wrapper(path=None, prefix='', onerror=None):
+            return walk_packages(path or default_path, prefix, onerror)
+        return wrapper
+
+    @contextlib.contextmanager
+    def restrict_walk_packages(self, path=None):
+        walk_packages = pkgutil.walk_packages
+        pkgutil.walk_packages = self._restricted_walk_packages(walk_packages,
+                                                               path)
+        try:
+            yield
+        finally:
+            pkgutil.walk_packages = walk_packages
+
+    def call_url_handler(self, url, expected_title):
+        text = pydoc._url_handler(url, "text/html")
+        result = get_html_title(text)
+        # Check the title to ensure an unexpected error page was not returned
+        self.assertEqual(result, expected_title, text)
+        return text
+
+
+class PydocDocTest(unittest.TestCase):
+    maxDiff = None
+
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_html_doc(self):
+        result, doc_loc = get_pydoc_html(pydoc_mod)
+        text_result = html2text(result)
+        text_lines = [line.strip() for line in text_result.splitlines()]
+        text_lines = [line for line in text_lines if line]
+        del text_lines[1]
+        expected_lines = html2text_of_expected.splitlines()
+        expected_lines = [line.strip() for line in expected_lines if line]
+        self.assertEqual(text_lines, expected_lines)
+        mod_file = inspect.getabsfile(pydoc_mod)
+        mod_url = urllib.parse.quote(mod_file)
+        self.assertIn(mod_url, result)
+        self.assertIn(mod_file, result)
+        self.assertIn(doc_loc, result)
+
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_text_doc(self):
+        result, doc_loc = get_pydoc_text(pydoc_mod)
+        expected_text = expected_text_pattern % (
+                        (doc_loc,) +
+                        expected_text_data_docstrings +
+                        (inspect.getabsfile(pydoc_mod),))
+        self.assertEqual(expected_text, result)
+
+    def test_text_enum_member_with_value_zero(self):
+        # Test issue #20654 to ensure enum member with value 0 can be
+        # displayed. It used to throw KeyError: 'zero'.
+        import enum
+        class BinaryInteger(enum.IntEnum):
+            zero = 0
+            one = 1
+        doc = pydoc.render_doc(BinaryInteger)
+        self.assertIn('BinaryInteger.zero', doc)
+
+    def test_mixed_case_module_names_are_lower_cased(self):
+        # issue16484
+        doc_link = get_pydoc_link(xml.etree.ElementTree)
+        self.assertIn('xml.etree.elementtree', doc_link)
+
+    def test_issue8225(self):
+        # Test issue8225 to ensure no doc link appears for xml.etree
+        result, doc_loc = get_pydoc_text(xml.etree)
+        self.assertEqual(doc_loc, "", "MODULE DOCS incorrectly includes a link")
+
+    def test_getpager_with_stdin_none(self):
+        previous_stdin = sys.stdin
+        try:
+            sys.stdin = None
+            pydoc.getpager() # Shouldn't fail.
+        finally:
+            sys.stdin = previous_stdin
+
+    def test_non_str_name(self):
+        # issue14638
+        # Treat illegal (non-str) name like no name
+
+        class A:
+            __name__ = 42
+        class B:
+            pass
+        adoc = pydoc.render_doc(A())
+        bdoc = pydoc.render_doc(B())
+        self.assertEqual(adoc.replace("A", "B"), bdoc)
+
+    def test_not_here(self):
+        missing_module = "test.i_am_not_here"
+        result = str(run_pydoc_fail(missing_module), 'ascii')
+        expected = missing_pattern % missing_module
+        self.assertEqual(expected, result,
+            "documentation for missing module found")
+
+    @requires_docstrings
+    def test_not_ascii(self):
+        result = run_pydoc('test.test_pydoc.test_pydoc.nonascii', PYTHONIOENCODING='ascii')
+        encoded = nonascii.__doc__.encode('ascii', 'backslashreplace')
+        self.assertIn(encoded, result)
+
+    def test_input_strip(self):
+        missing_module = " test.i_am_not_here "
+        result = str(run_pydoc_fail(missing_module), 'ascii')
+        expected = missing_pattern % missing_module.strip()
+        self.assertEqual(expected, result)
+
+    def test_stripid(self):
+        # test with strings, other implementations might have different repr()
+        stripid = pydoc.stripid
+        # strip the id
+        self.assertEqual(stripid('<function stripid at 0x88dcee4>'),
+                         '<function stripid>')
+        self.assertEqual(stripid('<function stripid at 0x01F65390>'),
+                         '<function stripid>')
+        # nothing to strip, return the same text
+        self.assertEqual(stripid('42'), '42')
+        self.assertEqual(stripid("<type 'exceptions.Exception'>"),
+                         "<type 'exceptions.Exception'>")
+
+    def test_builtin_with_more_than_four_children(self):
+        """Tests help on builtin object which have more than four child classes.
+
+        When running help() on a builtin class which has child classes, it
+        should contain a "Built-in subclasses" section and only 4 classes
+        should be displayed with a hint on how many more subclasses are present.
+        For example:
+
+        >>> help(object)
+        Help on class object in module builtins:
+
+        class object
+         |  The most base type
+         |
+         |  Built-in subclasses:
+         |      async_generator
+         |      BaseException
+         |      builtin_function_or_method
+         |      bytearray
+         |      ... and 82 other subclasses
+        """
+        doc = pydoc.TextDoc()
+        text = doc.docclass(object)
+        snip = (" |  Built-in subclasses:\n"
+                " |      async_generator\n"
+                " |      BaseException\n"
+                " |      builtin_function_or_method\n"
+                " |      bytearray\n"
+                " |      ... and \\d+ other subclasses")
+        self.assertRegex(text, snip)
+
+    def test_builtin_with_child(self):
+        """Tests help on builtin object which have only child classes.
+
+        When running help() on a builtin class which has child classes, it
+        should contain a "Built-in subclasses" section. For example:
+
+        >>> help(ArithmeticError)
+        Help on class ArithmeticError in module builtins:
+
+        class ArithmeticError(Exception)
+         |  Base class for arithmetic errors.
+         |
+         ...
+         |
+         |  Built-in subclasses:
+         |      FloatingPointError
+         |      OverflowError
+         |      ZeroDivisionError
+        """
+        doc = pydoc.TextDoc()
+        text = doc.docclass(ArithmeticError)
+        snip = (" |  Built-in subclasses:\n"
+                " |      FloatingPointError\n"
+                " |      OverflowError\n"
+                " |      ZeroDivisionError")
+        self.assertIn(snip, text)
+
+    def test_builtin_with_grandchild(self):
+        """Tests help on builtin classes which have grandchild classes.
+
+        When running help() on a builtin class which has child classes, it
+        should contain a "Built-in subclasses" section. However, if it also has
+        grandchildren, these should not show up on the subclasses section.
+        For example:
+
+        >>> help(Exception)
+        Help on class Exception in module builtins:
+
+        class Exception(BaseException)
+         |  Common base class for all non-exit exceptions.
+         |
+         ...
+         |
+         |  Built-in subclasses:
+         |      ArithmeticError
+         |      AssertionError
+         |      AttributeError
+         ...
+        """
+        doc = pydoc.TextDoc()
+        text = doc.docclass(Exception)
+        snip = (" |  Built-in subclasses:\n"
+                " |      ArithmeticError\n"
+                " |      AssertionError\n"
+                " |      AttributeError")
+        self.assertIn(snip, text)
+        # Testing that the grandchild ZeroDivisionError does not show up
+        self.assertNotIn('ZeroDivisionError', text)
+
+    def test_builtin_no_child(self):
+        """Tests help on builtin object which have no child classes.
+
+        When running help() on a builtin class which has no child classes, it
+        should not contain any "Built-in subclasses" section. For example:
+
+        >>> help(ZeroDivisionError)
+
+        Help on class ZeroDivisionError in module builtins:
+
+        class ZeroDivisionError(ArithmeticError)
+         |  Second argument to a division or modulo operation was zero.
+         |
+         |  Method resolution order:
+         |      ZeroDivisionError
+         |      ArithmeticError
+         |      Exception
+         |      BaseException
+         |      object
+         |
+         |  Methods defined here:
+         ...
+        """
+        doc = pydoc.TextDoc()
+        text = doc.docclass(ZeroDivisionError)
+        # Testing that the subclasses section does not appear
+        self.assertNotIn('Built-in subclasses', text)
+
+    def test_builtin_on_metaclasses(self):
+        """Tests help on metaclasses.
+
+        When running help() on a metaclasses such as type, it
+        should not contain any "Built-in subclasses" section.
+        """
+        doc = pydoc.TextDoc()
+        text = doc.docclass(type)
+        # Testing that the subclasses section does not appear
+        self.assertNotIn('Built-in subclasses', text)
+
+    def test_fail_help_cli(self):
+        elines = (missing_pattern % 'abd').splitlines()
+        with spawn_python("-c" "help()") as proc:
+            out, _ = proc.communicate(b"abd")
+            olines = out.decode().splitlines()[-9:-6]
+            olines[0] = olines[0].removeprefix('help> ')
+            self.assertEqual(elines, olines)
+
+    def test_fail_help_output_redirect(self):
+        with StringIO() as buf:
+            helper = pydoc.Helper(output=buf)
+            helper.help("abd")
+            expected = missing_pattern % "abd"
+            self.assertEqual(expected, buf.getvalue().strip().replace('\n', os.linesep))
+
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_help_output_redirect(self):
+        # issue 940286, if output is set in Helper, then all output from
+        # Helper.help should be redirected
+        getpager_old = pydoc.getpager
+        getpager_new = lambda: (lambda x: x)
+        self.maxDiff = None
+
+        buf = StringIO()
+        helper = pydoc.Helper(output=buf)
+        unused, doc_loc = get_pydoc_text(pydoc_mod)
+        module = "test.test_pydoc.pydoc_mod"
+        help_header = """
+        Help on module test.test_pydoc.pydoc_mod in test.test_pydoc:
+
+        """.lstrip()
+        help_header = textwrap.dedent(help_header)
+        expected_help_pattern = help_header + expected_text_pattern
+
+        pydoc.getpager = getpager_new
+        try:
+            with captured_output('stdout') as output, \
+                 captured_output('stderr') as err:
+                helper.help(module)
+                result = buf.getvalue().strip()
+                expected_text = expected_help_pattern % (
+                                (doc_loc,) +
+                                expected_text_data_docstrings +
+                                (inspect.getabsfile(pydoc_mod),))
+                self.assertEqual('', output.getvalue())
+                self.assertEqual('', err.getvalue())
+                self.assertEqual(expected_text, result)
+        finally:
+            pydoc.getpager = getpager_old
+
+    def test_namedtuple_fields(self):
+        Person = namedtuple('Person', ['nickname', 'firstname'])
+        with captured_stdout() as help_io:
+            pydoc.help(Person)
+        helptext = help_io.getvalue()
+        self.assertIn("nickname", helptext)
+        self.assertIn("firstname", helptext)
+        self.assertIn("Alias for field number 0", helptext)
+        self.assertIn("Alias for field number 1", helptext)
+
+    def test_namedtuple_public_underscore(self):
+        NT = namedtuple('NT', ['abc', 'def'], rename=True)
+        with captured_stdout() as help_io:
+            pydoc.help(NT)
+        helptext = help_io.getvalue()
+        self.assertIn('_1', helptext)
+        self.assertIn('_replace', helptext)
+        self.assertIn('_asdict', helptext)
+
+    def test_synopsis(self):
+        self.addCleanup(unlink, TESTFN)
+        for encoding in ('ISO-8859-1', 'UTF-8'):
+            with open(TESTFN, 'w', encoding=encoding) as script:
+                if encoding != 'UTF-8':
+                    print('#coding: {}'.format(encoding), file=script)
+                print('"""line 1: h\xe9', file=script)
+                print('line 2: hi"""', file=script)
+            synopsis = pydoc.synopsis(TESTFN, {})
+            self.assertEqual(synopsis, 'line 1: h\xe9')
+
+    @requires_docstrings
+    def test_synopsis_sourceless(self):
+        os = import_helper.import_fresh_module('os')
+        expected = os.__doc__.splitlines()[0]
+        filename = os.__spec__.cached
+        synopsis = pydoc.synopsis(filename)
+
+        self.assertEqual(synopsis, expected)
+
+    def test_synopsis_sourceless_empty_doc(self):
+        with os_helper.temp_cwd() as test_dir:
+            init_path = os.path.join(test_dir, 'foomod42.py')
+            cached_path = importlib.util.cache_from_source(init_path)
+            with open(init_path, 'w') as fobj:
+                fobj.write("foo = 1")
+            py_compile.compile(init_path)
+            synopsis = pydoc.synopsis(init_path, {})
+            self.assertIsNone(synopsis)
+            synopsis_cached = pydoc.synopsis(cached_path, {})
+            self.assertIsNone(synopsis_cached)
+
+    def test_splitdoc_with_description(self):
+        example_string = "I Am A Doc\n\n\nHere is my description"
+        self.assertEqual(pydoc.splitdoc(example_string),
+                         ('I Am A Doc', '\nHere is my description'))
+
+    def test_is_package_when_not_package(self):
+        with os_helper.temp_cwd() as test_dir:
+            with self.assertWarns(DeprecationWarning) as cm:
+                self.assertFalse(pydoc.ispackage(test_dir))
+            self.assertEqual(cm.filename, __file__)
+
+    def test_is_package_when_is_package(self):
+        with os_helper.temp_cwd() as test_dir:
+            init_path = os.path.join(test_dir, '__init__.py')
+            open(init_path, 'w').close()
+            with self.assertWarns(DeprecationWarning) as cm:
+                self.assertTrue(pydoc.ispackage(test_dir))
+            os.remove(init_path)
+            self.assertEqual(cm.filename, __file__)
+
+    def test_allmethods(self):
+        # issue 17476: allmethods was no longer returning unbound methods.
+        # This test is a bit fragile in the face of changes to object and type,
+        # but I can't think of a better way to do it without duplicating the
+        # logic of the function under test.
+
+        class TestClass(object):
+            def method_returning_true(self):
+                return True
+
+        # What we expect to get back: everything on object...
+        expected = dict(vars(object))
+        # ...plus our unbound method...
+        expected['method_returning_true'] = TestClass.method_returning_true
+        # ...but not the non-methods on object.
+        del expected['__doc__']
+        del expected['__class__']
+        # inspect resolves descriptors on type into methods, but vars doesn't,
+        # so we need to update __subclasshook__ and __init_subclass__.
+        expected['__subclasshook__'] = TestClass.__subclasshook__
+        expected['__init_subclass__'] = TestClass.__init_subclass__
+
+        methods = pydoc.allmethods(TestClass)
+        self.assertDictEqual(methods, expected)
+
+    @requires_docstrings
+    def test_method_aliases(self):
+        class A:
+            def tkraise(self, aboveThis=None):
+                """Raise this widget in the stacking order."""
+            lift = tkraise
+            def a_size(self):
+                """Return size"""
+        class B(A):
+            def itemconfigure(self, tagOrId, cnf=None, **kw):
+                """Configure resources of an item TAGORID."""
+            itemconfig = itemconfigure
+            b_size = A.a_size
+
+        doc = pydoc.render_doc(B)
+        doc = clean_text(doc)
+        self.assertEqual(doc, '''\
+Python Library Documentation: class B in module %s
+
+class B(A)
+ |  Method resolution order:
+ |      B
+ |      A
+ |      builtins.object
+ |
+ |  Methods defined here:
+ |
+ |  b_size = a_size(self)
+ |
+ |  itemconfig = itemconfigure(self, tagOrId, cnf=None, **kw)
+ |
+ |  itemconfigure(self, tagOrId, cnf=None, **kw)
+ |      Configure resources of an item TAGORID.
+ |
+ |  ----------------------------------------------------------------------
+ |  Methods inherited from A:
+ |
+ |  a_size(self)
+ |      Return size
+ |
+ |  lift = tkraise(self, aboveThis=None)
+ |
+ |  tkraise(self, aboveThis=None)
+ |      Raise this widget in the stacking order.
+ |
+ |  ----------------------------------------------------------------------
+ |  Data descriptors inherited from A:
+ |
+ |  __dict__
+ |      dictionary for instance variables
+ |
+ |  __weakref__
+ |      list of weak references to the object
+''' % __name__)
+
+        doc = pydoc.render_doc(B, renderer=pydoc.HTMLDoc())
+        expected_text = f"""
+Python Library Documentation
+
+class B in module {__name__}
+class B(A)
+    Method resolution order:
+        B
+        A
+        builtins.object
+
+    Methods defined here:
+        b_size = a_size(self)
+        itemconfig = itemconfigure(self, tagOrId, cnf=None, **kw)
+        itemconfigure(self, tagOrId, cnf=None, **kw)
+            Configure resources of an item TAGORID.
+
+    Methods inherited from A:
+        a_size(self)
+            Return size
+        lift = tkraise(self, aboveThis=None)
+        tkraise(self, aboveThis=None)
+            Raise this widget in the stacking order.
+
+    Data descriptors inherited from A:
+        __dict__
+            dictionary for instance variables
+        __weakref__
+            list of weak references to the object
+"""
+        as_text = html2text(doc)
+        expected_lines = [line.strip() for line in expected_text.split("\n") if line]
+        for expected_line in expected_lines:
+            self.assertIn(expected_line, as_text)
+
+    def test_long_signatures(self):
+        from collections.abc import Callable
+        from typing import Literal, Annotated
+
+        class A:
+            def __init__(self,
+                         arg1: Callable[[int, int, int], str],
+                         arg2: Literal['some value', 'other value'],
+                         arg3: Annotated[int, 'some docs about this type'],
+                         ) -> None:
+                ...
+
+        doc = pydoc.render_doc(A)
+        doc = clean_text(doc)
+        self.assertEqual(doc, '''Python Library Documentation: class A in module %s
+
+class A(builtins.object)
+ |  A(
+ |      arg1: collections.abc.Callable[[int, int, int], str],
+ |      arg2: Literal['some value', 'other value'],
+ |      arg3: Annotated[int, 'some docs about this type']
+ |  ) -> None
+ |
+ |  Methods defined here:
+ |
+ |  __init__(
+ |      self,
+ |      arg1: collections.abc.Callable[[int, int, int], str],
+ |      arg2: Literal['some value', 'other value'],
+ |      arg3: Annotated[int, 'some docs about this type']
+ |  ) -> None
+ |
+ |  ----------------------------------------------------------------------
+ |  Data descriptors defined here:
+ |
+ |  __dict__%s
+ |
+ |  __weakref__%s
+''' % (__name__,
+       '' if MISSING_C_DOCSTRINGS else '\n |      dictionary for instance variables',
+       '' if MISSING_C_DOCSTRINGS else '\n |      list of weak references to the object',
+      ))
+
+        def func(
+            arg1: Callable[[Annotated[int, 'Some doc']], str],
+            arg2: Literal[1, 2, 3, 4, 5, 6, 7, 8],
+        ) -> Annotated[int, 'Some other']:
+            ...
+
+        doc = pydoc.render_doc(func)
+        doc = clean_text(doc)
+        self.assertEqual(doc, '''Python Library Documentation: function func in module %s
+
+func(
+    arg1: collections.abc.Callable[[typing.Annotated[int, 'Some doc']], str],
+    arg2: Literal[1, 2, 3, 4, 5, 6, 7, 8]
+) -> Annotated[int, 'Some other']
+''' % __name__)
+
+        def function_with_really_long_name_so_annotations_can_be_rather_small(
+            arg1: int,
+            arg2: str,
+        ):
+            ...
+
+        doc = pydoc.render_doc(function_with_really_long_name_so_annotations_can_be_rather_small)
+        doc = clean_text(doc)
+        self.assertEqual(doc, '''Python Library Documentation: function function_with_really_long_name_so_annotations_can_be_rather_small in module %s
+
+function_with_really_long_name_so_annotations_can_be_rather_small(
+    arg1: int,
+    arg2: str
+)
+''' % __name__)
+
+        does_not_have_name = lambda \
+            very_long_parameter_name_that_should_not_fit_into_a_single_line, \
+            second_very_long_parameter_name: ...
+
+        doc = pydoc.render_doc(does_not_have_name)
+        doc = clean_text(doc)
+        self.assertEqual(doc, '''Python Library Documentation: function <lambda> in module %s
+
+<lambda> lambda very_long_parameter_name_that_should_not_fit_into_a_single_line, second_very_long_parameter_name
+''' % __name__)
+
+    def test__future__imports(self):
+        # __future__ features are excluded from module help,
+        # except when it's the __future__ module itself
+        import __future__
+        future_text, _ = get_pydoc_text(__future__)
+        future_html, _ = get_pydoc_html(__future__)
+        pydoc_mod_text, _ = get_pydoc_text(pydoc_mod)
+        pydoc_mod_html, _ = get_pydoc_html(pydoc_mod)
+
+        for feature in __future__.all_feature_names:
+            txt = f"{feature} = _Feature"
+            html = f"<strong>{feature}</strong> = _Feature"
+            self.assertIn(txt, future_text)
+            self.assertIn(html, future_html)
+            self.assertNotIn(txt, pydoc_mod_text)
+            self.assertNotIn(html, pydoc_mod_html)
+
+
+class PydocImportTest(PydocBaseTest):
+
+    def setUp(self):
+        self.test_dir = os.mkdir(TESTFN)
+        self.addCleanup(rmtree, TESTFN)
+        importlib.invalidate_caches()
+
+    def test_badimport(self):
+        # This tests the fix for issue 5230, where if pydoc found the module
+        # but the module had an internal import error pydoc would report no doc
+        # found.
+        modname = 'testmod_xyzzy'
+        testpairs = (
+            ('i_am_not_here', 'i_am_not_here'),
+            ('test.i_am_not_here_either', 'test.i_am_not_here_either'),
+            ('test.i_am_not_here.neither_am_i', 'test.i_am_not_here'),
+            ('i_am_not_here.{}'.format(modname), 'i_am_not_here'),
+            ('test.{}'.format(modname), 'test.{}'.format(modname)),
+            )
+
+        sourcefn = os.path.join(TESTFN, modname) + os.extsep + "py"
+        for importstring, expectedinmsg in testpairs:
+            with open(sourcefn, 'w') as f:
+                f.write("import {}\n".format(importstring))
+            result = run_pydoc_fail(modname, PYTHONPATH=TESTFN).decode("ascii")
+            expected = badimport_pattern % (modname, expectedinmsg)
+            self.assertEqual(expected, result)
+
+    def test_apropos_with_bad_package(self):
+        # Issue 7425 - pydoc -k failed when bad package on path
+        pkgdir = os.path.join(TESTFN, "syntaxerr")
+        os.mkdir(pkgdir)
+        badsyntax = os.path.join(pkgdir, "__init__") + os.extsep + "py"
+        with open(badsyntax, 'w') as f:
+            f.write("invalid python syntax = $1\n")
+        with self.restrict_walk_packages(path=[TESTFN]):
+            with captured_stdout() as out:
+                with captured_stderr() as err:
+                    pydoc.apropos('xyzzy')
+            # No result, no error
+            self.assertEqual(out.getvalue(), '')
+            self.assertEqual(err.getvalue(), '')
+            # The package name is still matched
+            with captured_stdout() as out:
+                with captured_stderr() as err:
+                    pydoc.apropos('syntaxerr')
+            self.assertEqual(out.getvalue().strip(), 'syntaxerr')
+            self.assertEqual(err.getvalue(), '')
+
+    def test_apropos_with_unreadable_dir(self):
+        # Issue 7367 - pydoc -k failed when unreadable dir on path
+        self.unreadable_dir = os.path.join(TESTFN, "unreadable")
+        os.mkdir(self.unreadable_dir, 0)
+        self.addCleanup(os.rmdir, self.unreadable_dir)
+        # Note, on Windows the directory appears to be still
+        #   readable so this is not really testing the issue there
+        with self.restrict_walk_packages(path=[TESTFN]):
+            with captured_stdout() as out:
+                with captured_stderr() as err:
+                    pydoc.apropos('SOMEKEY')
+        # No result, no error
+        self.assertEqual(out.getvalue(), '')
+        self.assertEqual(err.getvalue(), '')
+
+    @os_helper.skip_unless_working_chmod
+    @unittest.skipIf(is_emscripten, "cannot remove x bit")
+    def test_apropos_empty_doc(self):
+        pkgdir = os.path.join(TESTFN, 'walkpkg')
+        os.mkdir(pkgdir)
+        self.addCleanup(rmtree, pkgdir)
+        init_path = os.path.join(pkgdir, '__init__.py')
+        with open(init_path, 'w') as fobj:
+            fobj.write("foo = 1")
+        current_mode = stat.S_IMODE(os.stat(pkgdir).st_mode)
+        try:
+            os.chmod(pkgdir, current_mode & ~stat.S_IEXEC)
+            with self.restrict_walk_packages(path=[TESTFN]), captured_stdout() as stdout:
+                pydoc.apropos('')
+            self.assertIn('walkpkg', stdout.getvalue())
+        finally:
+            os.chmod(pkgdir, current_mode)
+
+    def test_url_search_package_error(self):
+        # URL handler search should cope with packages that raise exceptions
+        pkgdir = os.path.join(TESTFN, "test_error_package")
+        os.mkdir(pkgdir)
+        init = os.path.join(pkgdir, "__init__.py")
+        with open(init, "wt", encoding="ascii") as f:
+            f.write("""raise ValueError("ouch")\n""")
+        with self.restrict_walk_packages(path=[TESTFN]):
+            # Package has to be importable for the error to have any effect
+            saved_paths = tuple(sys.path)
+            sys.path.insert(0, TESTFN)
+            try:
+                with self.assertRaisesRegex(ValueError, "ouch"):
+                    import test_error_package  # Sanity check
+
+                text = self.call_url_handler("search?key=test_error_package",
+                    "Pydoc: Search Results")
+                found = ('<a href="test_error_package.html">'
+                    'test_error_package</a>')
+                self.assertIn(found, text)
+            finally:
+                sys.path[:] = saved_paths
+
+    @unittest.skip('causes undesirable side-effects (#20128)')
+    def test_modules(self):
+        # See Helper.listmodules().
+        num_header_lines = 2
+        num_module_lines_min = 5  # Playing it safe.
+        num_footer_lines = 3
+        expected = num_header_lines + num_module_lines_min + num_footer_lines
+
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        helper('modules')
+        result = output.getvalue().strip()
+        num_lines = len(result.splitlines())
+
+        self.assertGreaterEqual(num_lines, expected)
+
+    @unittest.skip('causes undesirable side-effects (#20128)')
+    def test_modules_search(self):
+        # See Helper.listmodules().
+        expected = 'pydoc - '
+
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        with captured_stdout() as help_io:
+            helper('modules pydoc')
+        result = help_io.getvalue()
+
+        self.assertIn(expected, result)
+
+    @unittest.skip('some buildbots are not cooperating (#20128)')
+    def test_modules_search_builtin(self):
+        expected = 'gc - '
+
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        with captured_stdout() as help_io:
+            helper('modules garbage')
+        result = help_io.getvalue()
+
+        self.assertTrue(result.startswith(expected))
+
+    def test_importfile(self):
+        loaded_pydoc = pydoc.importfile(pydoc.__file__)
+
+        self.assertIsNot(loaded_pydoc, pydoc)
+        self.assertEqual(loaded_pydoc.__name__, 'pydoc')
+        self.assertEqual(loaded_pydoc.__file__, pydoc.__file__)
+        self.assertEqual(loaded_pydoc.__spec__, pydoc.__spec__)
+
+
+class TestDescriptions(unittest.TestCase):
+
+    def test_module(self):
+        # Check that pydocfodder module can be described
+        doc = pydoc.render_doc(pydocfodder)
+        self.assertIn("pydocfodder", doc)
+
+    def test_class(self):
+        class C: "New-style class"
+        c = C()
+
+        self.assertEqual(pydoc.describe(C), 'class C')
+        self.assertEqual(pydoc.describe(c), 'C')
+        expected = 'C in module %s object' % __name__
+        self.assertIn(expected, pydoc.render_doc(c))
+
+    def test_generic_alias(self):
+        self.assertEqual(pydoc.describe(typing.List[int]), '_GenericAlias')
+        doc = pydoc.render_doc(typing.List[int], renderer=pydoc.plaintext)
+        self.assertIn('_GenericAlias in module typing', doc)
+        self.assertIn('List = class list(object)', doc)
+        if not MISSING_C_DOCSTRINGS:
+            self.assertIn(list.__doc__.strip().splitlines()[0], doc)
+
+        self.assertEqual(pydoc.describe(list[int]), 'GenericAlias')
+        doc = pydoc.render_doc(list[int], renderer=pydoc.plaintext)
+        self.assertIn('GenericAlias in module builtins', doc)
+        self.assertIn('\nclass list(object)', doc)
+        if not MISSING_C_DOCSTRINGS:
+            self.assertIn(list.__doc__.strip().splitlines()[0], doc)
+
+    def test_union_type(self):
+        self.assertEqual(pydoc.describe(typing.Union[int, str]), '_UnionGenericAlias')
+        doc = pydoc.render_doc(typing.Union[int, str], renderer=pydoc.plaintext)
+        self.assertIn('_UnionGenericAlias in module typing', doc)
+        self.assertIn('Union = typing.Union', doc)
+        if typing.Union.__doc__:
+            self.assertIn(typing.Union.__doc__.strip().splitlines()[0], doc)
+
+        self.assertEqual(pydoc.describe(int | str), 'UnionType')
+        doc = pydoc.render_doc(int | str, renderer=pydoc.plaintext)
+        self.assertIn('UnionType in module types object', doc)
+        self.assertIn('\nclass UnionType(builtins.object)', doc)
+        if not MISSING_C_DOCSTRINGS:
+            self.assertIn(types.UnionType.__doc__.strip().splitlines()[0], doc)
+
+    def test_special_form(self):
+        self.assertEqual(pydoc.describe(typing.NoReturn), '_SpecialForm')
+        doc = pydoc.render_doc(typing.NoReturn, renderer=pydoc.plaintext)
+        self.assertIn('_SpecialForm in module typing', doc)
+        if typing.NoReturn.__doc__:
+            self.assertIn('NoReturn = typing.NoReturn', doc)
+            self.assertIn(typing.NoReturn.__doc__.strip().splitlines()[0], doc)
+        else:
+            self.assertIn('NoReturn = class _SpecialForm(_Final)', doc)
+
+    def test_typing_pydoc(self):
+        def foo(data: typing.List[typing.Any],
+                x: int) -> typing.Iterator[typing.Tuple[int, typing.Any]]:
+            ...
+        T = typing.TypeVar('T')
+        class C(typing.Generic[T], typing.Mapping[int, str]): ...
+        self.assertEqual(pydoc.render_doc(foo).splitlines()[-1],
+                         'f\x08fo\x08oo\x08o(data: List[Any], x: int)'
+                         ' -> Iterator[Tuple[int, Any]]')
+        self.assertEqual(pydoc.render_doc(C).splitlines()[2],
+                         'class C\x08C(collections.abc.Mapping, typing.Generic)')
+
+    def test_builtin(self):
+        for name in ('str', 'str.translate', 'builtins.str',
+                     'builtins.str.translate'):
+            # test low-level function
+            self.assertIsNotNone(pydoc.locate(name))
+            # test high-level function
+            try:
+                pydoc.render_doc(name)
+            except ImportError:
+                self.fail('finding the doc of {!r} failed'.format(name))
+
+        for name in ('notbuiltins', 'strrr', 'strr.translate',
+                     'str.trrrranslate', 'builtins.strrr',
+                     'builtins.str.trrranslate'):
+            self.assertIsNone(pydoc.locate(name))
+            self.assertRaises(ImportError, pydoc.render_doc, name)
+
+    @staticmethod
+    def _get_summary_line(o):
+        text = pydoc.plain(pydoc.render_doc(o))
+        lines = text.split('\n')
+        assert len(lines) >= 2
+        return lines[2]
+
+    @staticmethod
+    def _get_summary_lines(o):
+        text = pydoc.plain(pydoc.render_doc(o))
+        lines = text.split('\n')
+        return '\n'.join(lines[2:])
+
+    # these should include "self"
+    def test_unbound_python_method(self):
+        self.assertEqual(self._get_summary_line(textwrap.TextWrapper.wrap),
+            "wrap(self, text)")
+
+    @requires_docstrings
+    def test_unbound_builtin_method(self):
+        self.assertEqual(self._get_summary_line(_pickle.Pickler.dump),
+            "dump(self, obj, /) unbound _pickle.Pickler method")
+
+    # these no longer include "self"
+    def test_bound_python_method(self):
+        t = textwrap.TextWrapper()
+        self.assertEqual(self._get_summary_line(t.wrap),
+            "wrap(text) method of textwrap.TextWrapper instance")
+    def test_field_order_for_named_tuples(self):
+        Person = namedtuple('Person', ['nickname', 'firstname', 'agegroup'])
+        s = pydoc.render_doc(Person)
+        self.assertLess(s.index('nickname'), s.index('firstname'))
+        self.assertLess(s.index('firstname'), s.index('agegroup'))
+
+        class NonIterableFields:
+            _fields = None
+
+        class NonHashableFields:
+            _fields = [[]]
+
+        # Make sure these doesn't fail
+        pydoc.render_doc(NonIterableFields)
+        pydoc.render_doc(NonHashableFields)
+
+    @requires_docstrings
+    def test_bound_builtin_method(self):
+        s = StringIO()
+        p = _pickle.Pickler(s)
+        self.assertEqual(self._get_summary_line(p.dump),
+            "dump(obj, /) method of _pickle.Pickler instance")
+
+    # this should *never* include self!
+    @requires_docstrings
+    def test_module_level_callable(self):
+        self.assertEqual(self._get_summary_line(os.stat),
+            "stat(path, *, dir_fd=None, follow_symlinks=True)")
+
+    def test_module_level_callable_noargs(self):
+        self.assertEqual(self._get_summary_line(time.time),
+            "time()")
+
+    def test_module_level_callable_o(self):
+        try:
+            import _stat
+        except ImportError:
+            # stat.S_IMODE() and _stat.S_IMODE() have a different signature
+            self.skipTest('_stat extension is missing')
+
+        self.assertEqual(self._get_summary_line(_stat.S_IMODE),
+            "S_IMODE(object, /)")
+
+    def test_unbound_builtin_method_noargs(self):
+        self.assertEqual(self._get_summary_line(str.lower),
+            "lower(self, /) unbound builtins.str method")
+
+    def test_bound_builtin_method_noargs(self):
+        self.assertEqual(self._get_summary_line(''.lower),
+            "lower() method of builtins.str instance")
+
+    def test_unbound_builtin_method_o(self):
+        self.assertEqual(self._get_summary_line(set.add),
+            "add(self, object, /) unbound builtins.set method")
+
+    def test_bound_builtin_method_o(self):
+        self.assertEqual(self._get_summary_line(set().add),
+            "add(object, /) method of builtins.set instance")
+
+    def test_unbound_builtin_method_coexist_o(self):
+        self.assertEqual(self._get_summary_line(set.__contains__),
+            "__contains__(self, object, /) unbound builtins.set method")
+
+    def test_bound_builtin_method_coexist_o(self):
+        self.assertEqual(self._get_summary_line(set().__contains__),
+            "__contains__(object, /) method of builtins.set instance")
+
+    def test_unbound_builtin_classmethod_noargs(self):
+        self.assertEqual(self._get_summary_line(datetime.datetime.__dict__['utcnow']),
+            "utcnow(type, /) unbound datetime.datetime method")
+
+    def test_bound_builtin_classmethod_noargs(self):
+        self.assertEqual(self._get_summary_line(datetime.datetime.utcnow),
+            "utcnow() class method of datetime.datetime")
+
+    def test_unbound_builtin_classmethod_o(self):
+        self.assertEqual(self._get_summary_line(dict.__dict__['__class_getitem__']),
+            "__class_getitem__(type, object, /) unbound builtins.dict method")
+
+    def test_bound_builtin_classmethod_o(self):
+        self.assertEqual(self._get_summary_line(dict.__class_getitem__),
+            "__class_getitem__(object, /) class method of builtins.dict")
+
+    @support.cpython_only
+    @requires_docstrings
+    def test_module_level_callable_unrepresentable_default(self):
+        import _testcapi
+        builtin = _testcapi.func_with_unrepresentable_signature
+        self.assertEqual(self._get_summary_line(builtin),
+            "func_with_unrepresentable_signature(a, b=<x>)")
+
+    @support.cpython_only
+    @requires_docstrings
+    def test_builtin_staticmethod_unrepresentable_default(self):
+        self.assertEqual(self._get_summary_line(str.maketrans),
+            "maketrans(x, y=<unrepresentable>, z=<unrepresentable>, /)")
+        import _testcapi
+        cls = _testcapi.DocStringUnrepresentableSignatureTest
+        self.assertEqual(self._get_summary_line(cls.staticmeth),
+            "staticmeth(a, b=<x>)")
+
+    @support.cpython_only
+    @requires_docstrings
+    def test_unbound_builtin_method_unrepresentable_default(self):
+        self.assertEqual(self._get_summary_line(dict.pop),
+            "pop(self, key, default=<unrepresentable>, /) "
+            "unbound builtins.dict method")
+        import _testcapi
+        cls = _testcapi.DocStringUnrepresentableSignatureTest
+        self.assertEqual(self._get_summary_line(cls.meth),
+            "meth(self, /, a, b=<x>) unbound "
+            "_testcapi.DocStringUnrepresentableSignatureTest method")
+
+    @support.cpython_only
+    @requires_docstrings
+    def test_bound_builtin_method_unrepresentable_default(self):
+        self.assertEqual(self._get_summary_line({}.pop),
+            "pop(key, default=<unrepresentable>, /) "
+            "method of builtins.dict instance")
+        import _testcapi
+        obj = _testcapi.DocStringUnrepresentableSignatureTest()
+        self.assertEqual(self._get_summary_line(obj.meth),
+            "meth(a, b=<x>) "
+            "method of _testcapi.DocStringUnrepresentableSignatureTest instance")
+
+    @support.cpython_only
+    @requires_docstrings
+    def test_unbound_builtin_classmethod_unrepresentable_default(self):
+        import _testcapi
+        cls = _testcapi.DocStringUnrepresentableSignatureTest
+        descr = cls.__dict__['classmeth']
+        self.assertEqual(self._get_summary_line(descr),
+            "classmeth(type, /, a, b=<x>) unbound "
+            "_testcapi.DocStringUnrepresentableSignatureTest method")
+
+    @support.cpython_only
+    @requires_docstrings
+    def test_bound_builtin_classmethod_unrepresentable_default(self):
+        import _testcapi
+        cls = _testcapi.DocStringUnrepresentableSignatureTest
+        self.assertEqual(self._get_summary_line(cls.classmeth),
+            "classmeth(a, b=<x>) class method of "
+            "_testcapi.DocStringUnrepresentableSignatureTest")
+
+    def test_overridden_text_signature(self):
+        class C:
+            def meth(*args, **kwargs):
+                pass
+            @classmethod
+            def cmeth(*args, **kwargs):
+                pass
+            @staticmethod
+            def smeth(*args, **kwargs):
+                pass
+        for text_signature, unbound, bound in [
+            ("($slf)", "(slf, /)", "()"),
+            ("($slf, /)", "(slf, /)", "()"),
+            ("($slf, /, arg)", "(slf, /, arg)", "(arg)"),
+            ("($slf, /, arg=<x>)", "(slf, /, arg=<x>)", "(arg=<x>)"),
+            ("($slf, arg, /)", "(slf, arg, /)", "(arg, /)"),
+            ("($slf, arg=<x>, /)", "(slf, arg=<x>, /)", "(arg=<x>, /)"),
+            ("(/, slf, arg)", "(/, slf, arg)", "(/, slf, arg)"),
+            ("(/, slf, arg=<x>)", "(/, slf, arg=<x>)", "(/, slf, arg=<x>)"),
+            ("(slf, /, arg)", "(slf, /, arg)", "(arg)"),
+            ("(slf, /, arg=<x>)", "(slf, /, arg=<x>)", "(arg=<x>)"),
+            ("(slf, arg, /)", "(slf, arg, /)", "(arg, /)"),
+            ("(slf, arg=<x>, /)", "(slf, arg=<x>, /)", "(arg=<x>, /)"),
+        ]:
+            with self.subTest(text_signature):
+                C.meth.__text_signature__ = text_signature
+                self.assertEqual(self._get_summary_line(C.meth),
+                        "meth" + unbound)
+                self.assertEqual(self._get_summary_line(C().meth),
+                        "meth" + bound + " method of test.test_pydoc.test_pydoc.C instance")
+                C.cmeth.__func__.__text_signature__ = text_signature
+                self.assertEqual(self._get_summary_line(C.cmeth),
+                        "cmeth" + bound + " class method of test.test_pydoc.test_pydoc.C")
+                C.smeth.__text_signature__ = text_signature
+                self.assertEqual(self._get_summary_line(C.smeth),
+                        "smeth" + unbound)
+
+    @requires_docstrings
+    def test_staticmethod(self):
+        class X:
+            @staticmethod
+            def sm(x, y):
+                '''A static method'''
+                ...
+        self.assertEqual(self._get_summary_lines(X.__dict__['sm']),
+                         'sm(x, y)\n'
+                         '    A static method\n')
+        self.assertEqual(self._get_summary_lines(X.sm), """\
+sm(x, y)
+    A static method
+""")
+        self.assertIn("""
+ |  Static methods defined here:
+ |
+ |  sm(x, y)
+ |      A static method
+""", pydoc.plain(pydoc.render_doc(X)))
+
+    @requires_docstrings
+    def test_classmethod(self):
+        class X:
+            @classmethod
+            def cm(cls, x):
+                '''A class method'''
+                ...
+        self.assertEqual(self._get_summary_lines(X.__dict__['cm']),
+                         'cm(...)\n'
+                         '    A class method\n')
+        self.assertEqual(self._get_summary_lines(X.cm), """\
+cm(x) class method of test.test_pydoc.test_pydoc.X
+    A class method
+""")
+        self.assertIn("""
+ |  Class methods defined here:
+ |
+ |  cm(x)
+ |      A class method
+""", pydoc.plain(pydoc.render_doc(X)))
+
+    @requires_docstrings
+    def test_getset_descriptor(self):
+        # Currently these attributes are implemented as getset descriptors
+        # in CPython.
+        self.assertEqual(self._get_summary_line(int.numerator), "numerator")
+        self.assertEqual(self._get_summary_line(float.real), "real")
+        self.assertEqual(self._get_summary_line(Exception.args), "args")
+        self.assertEqual(self._get_summary_line(memoryview.obj), "obj")
+
+    @requires_docstrings
+    def test_member_descriptor(self):
+        # Currently these attributes are implemented as member descriptors
+        # in CPython.
+        self.assertEqual(self._get_summary_line(complex.real), "real")
+        self.assertEqual(self._get_summary_line(range.start), "start")
+        self.assertEqual(self._get_summary_line(slice.start), "start")
+        self.assertEqual(self._get_summary_line(property.fget), "fget")
+        self.assertEqual(self._get_summary_line(StopIteration.value), "value")
+
+    @requires_docstrings
+    def test_slot_descriptor(self):
+        class Point:
+            __slots__ = 'x', 'y'
+        self.assertEqual(self._get_summary_line(Point.x), "x")
+
+    @requires_docstrings
+    def test_dict_attr_descriptor(self):
+        class NS:
+            pass
+        self.assertEqual(self._get_summary_line(NS.__dict__['__dict__']),
+                         "__dict__")
+
+    @requires_docstrings
+    def test_structseq_member_descriptor(self):
+        self.assertEqual(self._get_summary_line(type(sys.hash_info).width),
+                         "width")
+        self.assertEqual(self._get_summary_line(type(sys.flags).debug),
+                         "debug")
+        self.assertEqual(self._get_summary_line(type(sys.version_info).major),
+                         "major")
+        self.assertEqual(self._get_summary_line(type(sys.float_info).max),
+                         "max")
+
+    @requires_docstrings
+    def test_namedtuple_field_descriptor(self):
+        Box = namedtuple('Box', ('width', 'height'))
+        self.assertEqual(self._get_summary_lines(Box.width), """\
+    Alias for field number 0
+""")
+
+    @requires_docstrings
+    def test_property(self):
+        class Rect:
+            @property
+            def area(self):
+                '''Area of the rect'''
+                return self.w * self.h
+
+        self.assertEqual(self._get_summary_lines(Rect.area), """\
+    Area of the rect
+""")
+        self.assertIn("""
+ |  area
+ |      Area of the rect
+""", pydoc.plain(pydoc.render_doc(Rect)))
+
+    @requires_docstrings
+    def test_custom_non_data_descriptor(self):
+        class Descr:
+            def __get__(self, obj, cls):
+                if obj is None:
+                    return self
+                return 42
+        class X:
+            attr = Descr()
+
+        self.assertEqual(self._get_summary_lines(X.attr), f"""\
+<{__name__}.TestDescriptions.test_custom_non_data_descriptor.<locals>.Descr object>""")
+
+        X.attr.__doc__ = 'Custom descriptor'
+        self.assertEqual(self._get_summary_lines(X.attr), f"""\
+<{__name__}.TestDescriptions.test_custom_non_data_descriptor.<locals>.Descr object>
+    Custom descriptor
+""")
+
+        X.attr.__name__ = 'foo'
+        self.assertEqual(self._get_summary_lines(X.attr), """\
+foo(...)
+    Custom descriptor
+""")
+
+    @requires_docstrings
+    def test_custom_data_descriptor(self):
+        class Descr:
+            def __get__(self, obj, cls):
+                if obj is None:
+                    return self
+                return 42
+            def __set__(self, obj, cls):
+                1/0
+        class X:
+            attr = Descr()
+
+        self.assertEqual(self._get_summary_lines(X.attr), "")
+
+        X.attr.__doc__ = 'Custom descriptor'
+        self.assertEqual(self._get_summary_lines(X.attr), """\
+    Custom descriptor
+""")
+
+        X.attr.__name__ = 'foo'
+        self.assertEqual(self._get_summary_lines(X.attr), """\
+foo
+    Custom descriptor
+""")
+
+    def test_async_annotation(self):
+        async def coro_function(ign) -> int:
+            return 1
+
+        text = pydoc.plain(pydoc.plaintext.document(coro_function))
+        self.assertIn('async coro_function', text)
+
+        html = pydoc.HTMLDoc().document(coro_function)
+        self.assertIn(
+            'async <a name="-coro_function"><strong>coro_function',
+            html)
+
+    def test_async_generator_annotation(self):
+        async def an_async_generator():
+            yield 1
+
+        text = pydoc.plain(pydoc.plaintext.document(an_async_generator))
+        self.assertIn('async an_async_generator', text)
+
+        html = pydoc.HTMLDoc().document(an_async_generator)
+        self.assertIn(
+            'async <a name="-an_async_generator"><strong>an_async_generator',
+            html)
+
+    @requires_docstrings
+    def test_html_for_https_links(self):
+        def a_fn_with_https_link():
+            """a link https://localhost/"""
+            pass
+
+        html = pydoc.HTMLDoc().document(a_fn_with_https_link)
+        self.assertIn(
+            '<a href="https://localhost/">https://localhost/</a>',
+            html
+        )
+
+
+class PydocFodderTest(unittest.TestCase):
+
+    def getsection(self, text, beginline, endline):
+        lines = text.splitlines()
+        beginindex, endindex = 0, None
+        if beginline is not None:
+            beginindex = lines.index(beginline)
+        if endline is not None:
+            endindex = lines.index(endline, beginindex)
+        return lines[beginindex:endindex]
+
+    def test_text_doc_routines_in_class(self, cls=pydocfodder.B):
+        doc = pydoc.TextDoc()
+        result = doc.docclass(cls)
+        result = clean_text(result)
+        where = 'defined here' if cls is pydocfodder.B else 'inherited from B'
+        lines = self.getsection(result, f' |  Methods {where}:', ' |  ' + '-'*70)
+        self.assertIn(' |  A_method_alias = A_method(self)', lines)
+        self.assertIn(' |  B_method_alias = B_method(self)', lines)
+        self.assertIn(' |  A_staticmethod(x, y) from test.test_pydoc.pydocfodder.A', lines)
+        self.assertIn(' |  A_staticmethod_alias = A_staticmethod(x, y)', lines)
+        self.assertIn(' |  global_func(x, y) from test.test_pydoc.pydocfodder', lines)
+        self.assertIn(' |  global_func_alias = global_func(x, y)', lines)
+        self.assertIn(' |  global_func2_alias = global_func2(x, y) from test.test_pydoc.pydocfodder', lines)
+        self.assertIn(' |  __repr__(self, /) from builtins.object', lines)
+        self.assertIn(' |  object_repr = __repr__(self, /)', lines)
+
+        lines = self.getsection(result, f' |  Static methods {where}:', ' |  ' + '-'*70)
+        self.assertIn(' |  A_classmethod_ref = A_classmethod(x) class method of test.test_pydoc.pydocfodder.A', lines)
+        note = '' if cls is pydocfodder.B else ' class method of test.test_pydoc.pydocfodder.B'
+        self.assertIn(' |  B_classmethod_ref = B_classmethod(x)' + note, lines)
+        self.assertIn(' |  A_method_ref = A_method() method of test.test_pydoc.pydocfodder.A instance', lines)
+        self.assertIn(' |  get(key, default=None, /) method of builtins.dict instance', lines)
+        self.assertIn(' |  dict_get = get(key, default=None, /) method of builtins.dict instance', lines)
+
+        lines = self.getsection(result, f' |  Class methods {where}:', ' |  ' + '-'*70)
+        self.assertIn(' |  B_classmethod(x)', lines)
+        self.assertIn(' |  B_classmethod_alias = B_classmethod(x)', lines)
+
+    def test_html_doc_routines_in_class(self, cls=pydocfodder.B):
+        doc = pydoc.HTMLDoc()
+        result = doc.docclass(cls)
+        result = html2text(result)
+        where = 'defined here' if cls is pydocfodder.B else 'inherited from B'
+        lines = self.getsection(result, f'Methods {where}:', '-'*70)
+        self.assertIn('A_method_alias = A_method(self)', lines)
+        self.assertIn('B_method_alias = B_method(self)', lines)
+        self.assertIn('A_staticmethod(x, y) from test.test_pydoc.pydocfodder.A', lines)
+        self.assertIn('A_staticmethod_alias = A_staticmethod(x, y)', lines)
+        self.assertIn('global_func(x, y) from test.test_pydoc.pydocfodder', lines)
+        self.assertIn('global_func_alias = global_func(x, y)', lines)
+        self.assertIn('global_func2_alias = global_func2(x, y) from test.test_pydoc.pydocfodder', lines)
+        self.assertIn('__repr__(self, /) from builtins.object', lines)
+        self.assertIn('object_repr = __repr__(self, /)', lines)
+
+        lines = self.getsection(result, f'Static methods {where}:', '-'*70)
+        self.assertIn('A_classmethod_ref = A_classmethod(x) class method of test.test_pydoc.pydocfodder.A', lines)
+        note = '' if cls is pydocfodder.B else ' class method of test.test_pydoc.pydocfodder.B'
+        self.assertIn('B_classmethod_ref = B_classmethod(x)' + note, lines)
+        self.assertIn('A_method_ref = A_method() method of test.test_pydoc.pydocfodder.A instance', lines)
+
+        lines = self.getsection(result, f'Class methods {where}:', '-'*70)
+        self.assertIn('B_classmethod(x)', lines)
+        self.assertIn('B_classmethod_alias = B_classmethod(x)', lines)
+
+    def test_text_doc_inherited_routines_in_class(self):
+        self.test_text_doc_routines_in_class(pydocfodder.D)
+
+    def test_html_doc_inherited_routines_in_class(self):
+        self.test_html_doc_routines_in_class(pydocfodder.D)
+
+    def test_text_doc_routines_in_module(self):
+        doc = pydoc.TextDoc()
+        result = doc.docmodule(pydocfodder)
+        result = clean_text(result)
+        lines = self.getsection(result, 'FUNCTIONS', 'FILE')
+        # function alias
+        self.assertIn('    global_func_alias = global_func(x, y)', lines)
+        self.assertIn('    A_staticmethod(x, y)', lines)
+        self.assertIn('    A_staticmethod_alias = A_staticmethod(x, y)', lines)
+        # bound class methods
+        self.assertIn('    A_classmethod(x) class method of A', lines)
+        self.assertIn('    A_classmethod2 = A_classmethod(x) class method of A', lines)
+        self.assertIn('    A_classmethod3 = A_classmethod(x) class method of B', lines)
+        # bound methods
+        self.assertIn('    A_method() method of A instance', lines)
+        self.assertIn('    A_method2 = A_method() method of A instance', lines)
+        self.assertIn('    A_method3 = A_method() method of B instance', lines)
+        self.assertIn('    A_staticmethod_ref = A_staticmethod(x, y)', lines)
+        self.assertIn('    A_staticmethod_ref2 = A_staticmethod(y) method of B instance', lines)
+        self.assertIn('    get(key, default=None, /) method of builtins.dict instance', lines)
+        self.assertIn('    dict_get = get(key, default=None, /) method of builtins.dict instance', lines)
+        # unbound methods
+        self.assertIn('    B_method(self)', lines)
+        self.assertIn('    B_method2 = B_method(self)', lines)
+
+    def test_html_doc_routines_in_module(self):
+        doc = pydoc.HTMLDoc()
+        result = doc.docmodule(pydocfodder)
+        result = html2text(result)
+        lines = self.getsection(result, ' Functions', None)
+        # function alias
+        self.assertIn(' global_func_alias = global_func(x, y)', lines)
+        self.assertIn(' A_staticmethod(x, y)', lines)
+        self.assertIn(' A_staticmethod_alias = A_staticmethod(x, y)', lines)
+        # bound class methods
+        self.assertIn('A_classmethod(x) class method of A', lines)
+        self.assertIn(' A_classmethod2 = A_classmethod(x) class method of A', lines)
+        self.assertIn(' A_classmethod3 = A_classmethod(x) class method of B', lines)
+        # bound methods
+        self.assertIn(' A_method() method of A instance', lines)
+        self.assertIn(' A_method2 = A_method() method of A instance', lines)
+        self.assertIn(' A_method3 = A_method() method of B instance', lines)
+        self.assertIn(' A_staticmethod_ref = A_staticmethod(x, y)', lines)
+        self.assertIn(' A_staticmethod_ref2 = A_staticmethod(y) method of B instance', lines)
+        self.assertIn(' get(key, default=None, /) method of builtins.dict instance', lines)
+        self.assertIn(' dict_get = get(key, default=None, /) method of builtins.dict instance', lines)
+        # unbound methods
+        self.assertIn(' B_method(self)', lines)
+        self.assertIn(' B_method2 = B_method(self)', lines)
+
+
+@unittest.skipIf(
+    is_emscripten or is_wasi,
+    "Socket server not available on Emscripten/WASI."
+)
+class PydocServerTest(unittest.TestCase):
+    """Tests for pydoc._start_server"""
+
+    def test_server(self):
+        # Minimal test that starts the server, checks that it works, then stops
+        # it and checks its cleanup.
+        def my_url_handler(url, content_type):
+            text = 'the URL sent was: (%s, %s)' % (url, content_type)
+            return text
+
+        serverthread = pydoc._start_server(
+            my_url_handler,
+            hostname='localhost',
+            port=0,
+            )
+        self.assertEqual(serverthread.error, None)
+        self.assertTrue(serverthread.serving)
+        self.addCleanup(
+            lambda: serverthread.stop() if serverthread.serving else None
+            )
+        self.assertIn('localhost', serverthread.url)
+
+        self.addCleanup(urlcleanup)
+        self.assertEqual(
+            b'the URL sent was: (/test, text/html)',
+            urlopen(urllib.parse.urljoin(serverthread.url, '/test')).read(),
+            )
+        self.assertEqual(
+            b'the URL sent was: (/test.css, text/css)',
+            urlopen(urllib.parse.urljoin(serverthread.url, '/test.css')).read(),
+            )
+
+        serverthread.stop()
+        self.assertFalse(serverthread.serving)
+        self.assertIsNone(serverthread.docserver)
+        self.assertIsNone(serverthread.url)
+
+
+class PydocUrlHandlerTest(PydocBaseTest):
+    """Tests for pydoc._url_handler"""
+
+    def test_content_type_err(self):
+        f = pydoc._url_handler
+        self.assertRaises(TypeError, f, 'A', '')
+        self.assertRaises(TypeError, f, 'B', 'foobar')
+
+    def test_url_requests(self):
+        # Test for the correct title in the html pages returned.
+        # This tests the different parts of the URL handler without
+        # getting too picky about the exact html.
+        requests = [
+            ("", "Pydoc: Index of Modules"),
+            ("get?key=", "Pydoc: Index of Modules"),
+            ("index", "Pydoc: Index of Modules"),
+            ("topics", "Pydoc: Topics"),
+            ("keywords", "Pydoc: Keywords"),
+            ("pydoc", "Pydoc: module pydoc"),
+            ("get?key=pydoc", "Pydoc: module pydoc"),
+            ("search?key=pydoc", "Pydoc: Search Results"),
+            ("topic?key=def", "Pydoc: KEYWORD def"),
+            ("topic?key=STRINGS", "Pydoc: TOPIC STRINGS"),
+            ("foobar", "Pydoc: Error - foobar"),
+            ]
+
+        with self.restrict_walk_packages():
+            for url, title in requests:
+                self.call_url_handler(url, title)
+
+
+class TestHelper(unittest.TestCase):
+    def test_keywords(self):
+        self.assertEqual(sorted(pydoc.Helper.keywords),
+                         sorted(keyword.kwlist))
+
+
+class PydocWithMetaClasses(unittest.TestCase):
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_DynamicClassAttribute(self):
+        class Meta(type):
+            def __getattr__(self, name):
+                if name == 'ham':
+                    return 'spam'
+                return super().__getattr__(name)
+        class DA(metaclass=Meta):
+            @types.DynamicClassAttribute
+            def ham(self):
+                return 'eggs'
+        expected_text_data_docstrings = tuple('\n |      ' + s if s else ''
+                                      for s in expected_data_docstrings)
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        helper(DA)
+        expected_text = expected_dynamicattribute_pattern % (
+                (__name__,) + expected_text_data_docstrings[:2])
+        result = output.getvalue().strip()
+        self.assertEqual(expected_text, result)
+
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_virtualClassAttributeWithOneMeta(self):
+        class Meta(type):
+            def __dir__(cls):
+                return ['__class__', '__module__', '__name__', 'LIFE']
+            def __getattr__(self, name):
+                if name =='LIFE':
+                    return 42
+                return super().__getattr(name)
+        class Class(metaclass=Meta):
+            pass
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        helper(Class)
+        expected_text = expected_virtualattribute_pattern1 % __name__
+        result = output.getvalue().strip()
+        self.assertEqual(expected_text, result)
+
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_virtualClassAttributeWithTwoMeta(self):
+        class Meta1(type):
+            def __dir__(cls):
+                return ['__class__', '__module__', '__name__', 'one']
+            def __getattr__(self, name):
+                if name =='one':
+                    return 1
+                return super().__getattr__(name)
+        class Meta2(type):
+            def __dir__(cls):
+                return ['__class__', '__module__', '__name__', 'two']
+            def __getattr__(self, name):
+                if name =='two':
+                    return 2
+                return super().__getattr__(name)
+        class Meta3(Meta1, Meta2):
+            def __dir__(cls):
+                return list(sorted(set(
+                    ['__class__', '__module__', '__name__', 'three'] +
+                    Meta1.__dir__(cls) + Meta2.__dir__(cls))))
+            def __getattr__(self, name):
+                if name =='three':
+                    return 3
+                return super().__getattr__(name)
+        class Class1(metaclass=Meta1):
+            pass
+        class Class2(Class1, metaclass=Meta3):
+            pass
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        helper(Class1)
+        expected_text1 = expected_virtualattribute_pattern2 % __name__
+        result1 = output.getvalue().strip()
+        self.assertEqual(expected_text1, result1)
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        helper(Class2)
+        expected_text2 = expected_virtualattribute_pattern3 % __name__
+        result2 = output.getvalue().strip()
+        self.assertEqual(expected_text2, result2)
+
+    @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
+                     'trace function introduces __locals__ unexpectedly')
+    @requires_docstrings
+    def test_buggy_dir(self):
+        class M(type):
+            def __dir__(cls):
+                return ['__class__', '__name__', 'missing', 'here']
+        class C(metaclass=M):
+            here = 'present!'
+        output = StringIO()
+        helper = pydoc.Helper(output=output)
+        helper(C)
+        expected_text = expected_missingattribute_pattern % __name__
+        result = output.getvalue().strip()
+        self.assertEqual(expected_text, result)
+
+    def test_resolve_false(self):
+        # Issue #23008: pydoc enum.{,Int}Enum failed
+        # because bool(enum.Enum) is False.
+        with captured_stdout() as help_io:
+            pydoc.help('enum.Enum')
+        helptext = help_io.getvalue()
+        self.assertIn('class Enum', helptext)
+
+
+class TestInternalUtilities(unittest.TestCase):
+
+    def setUp(self):
+        tmpdir = tempfile.TemporaryDirectory()
+        self.argv0dir = tmpdir.name
+        self.argv0 = os.path.join(tmpdir.name, "nonexistent")
+        self.addCleanup(tmpdir.cleanup)
+        self.abs_curdir = abs_curdir = os.getcwd()
+        self.curdir_spellings = ["", os.curdir, abs_curdir]
+
+    def _get_revised_path(self, given_path, argv0=None):
+        # Checking that pydoc.cli() actually calls pydoc._get_revised_path()
+        # is handled via code review (at least for now).
+        if argv0 is None:
+            argv0 = self.argv0
+        return pydoc._get_revised_path(given_path, argv0)
+
+    def _get_starting_path(self):
+        # Get a copy of sys.path without the current directory.
+        clean_path = sys.path.copy()
+        for spelling in self.curdir_spellings:
+            for __ in range(clean_path.count(spelling)):
+                clean_path.remove(spelling)
+        return clean_path
+
+    def test_sys_path_adjustment_adds_missing_curdir(self):
+        clean_path = self._get_starting_path()
+        expected_path = [self.abs_curdir] + clean_path
+        self.assertEqual(self._get_revised_path(clean_path), expected_path)
+
+    def test_sys_path_adjustment_removes_argv0_dir(self):
+        clean_path = self._get_starting_path()
+        expected_path = [self.abs_curdir] + clean_path
+        leading_argv0dir = [self.argv0dir] + clean_path
+        self.assertEqual(self._get_revised_path(leading_argv0dir), expected_path)
+        trailing_argv0dir = clean_path + [self.argv0dir]
+        self.assertEqual(self._get_revised_path(trailing_argv0dir), expected_path)
+
+    def test_sys_path_adjustment_protects_pydoc_dir(self):
+        def _get_revised_path(given_path):
+            return self._get_revised_path(given_path, argv0=pydoc.__file__)
+        clean_path = self._get_starting_path()
+        leading_argv0dir = [self.argv0dir] + clean_path
+        expected_path = [self.abs_curdir] + leading_argv0dir
+        self.assertEqual(_get_revised_path(leading_argv0dir), expected_path)
+        trailing_argv0dir = clean_path + [self.argv0dir]
+        expected_path = [self.abs_curdir] + trailing_argv0dir
+        self.assertEqual(_get_revised_path(trailing_argv0dir), expected_path)
+
+    def test_sys_path_adjustment_when_curdir_already_included(self):
+        clean_path = self._get_starting_path()
+        for spelling in self.curdir_spellings:
+            with self.subTest(curdir_spelling=spelling):
+                # If curdir is already present, no alterations are made at all
+                leading_curdir = [spelling] + clean_path
+                self.assertIsNone(self._get_revised_path(leading_curdir))
+                trailing_curdir = clean_path + [spelling]
+                self.assertIsNone(self._get_revised_path(trailing_curdir))
+                leading_argv0dir = [self.argv0dir] + leading_curdir
+                self.assertIsNone(self._get_revised_path(leading_argv0dir))
+                trailing_argv0dir = trailing_curdir + [self.argv0dir]
+                self.assertIsNone(self._get_revised_path(trailing_argv0dir))
+
+
+def setUpModule():
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
+    unittest.addModuleCleanup(reap_children)
+
+
+if __name__ == "__main__":
+    unittest.main()