cpython/Lib/test/test_readline.py

"""
Very minimal unittests for parts of the readline module.
"""
import locale
import os
import sys
import tempfile
import textwrap
import threading
import unittest
from test import support
from test.support import threading_helper
from test.support import verbose
from test.support.import_helper import import_module
from test.support.os_helper import unlink, temp_dir, TESTFN
from test.support.pty_helper import run_pty
from test.support.script_helper import assert_python_ok
from test.support.threading_helper import requires_working_threading

# Skip tests if there is no readline module
readline = import_module('readline')

if hasattr(readline, "_READLINE_LIBRARY_VERSION"):
    is_editline = ("EditLine wrapper" in readline._READLINE_LIBRARY_VERSION)
else:
    is_editline = readline.backend == "editline"


def setUpModule():
    if verbose:
        # Python implementations other than CPython may not have
        # these private attributes
        if hasattr(readline, "_READLINE_VERSION"):
            print(f"readline version: {readline._READLINE_VERSION:#x}")
            print(f"readline runtime version: {readline._READLINE_RUNTIME_VERSION:#x}")
        if hasattr(readline, "_READLINE_LIBRARY_VERSION"):
            print(f"readline library version: {readline._READLINE_LIBRARY_VERSION!r}")
        print(f"use libedit emulation? {is_editline}")


@unittest.skipUnless(hasattr(readline, "clear_history"),
                     "The history update test cannot be run because the "
                     "clear_history method is not available.")
class TestHistoryManipulation (unittest.TestCase):
    """
    These tests were added to check that the libedit emulation on OSX and the
    "real" readline have the same interface for history manipulation. That's
    why the tests cover only a small subset of the interface.
    """

    def testHistoryUpdates(self):
        readline.clear_history()

        readline.add_history("first line")
        readline.add_history("second line")

        self.assertEqual(readline.get_history_item(0), None)
        self.assertEqual(readline.get_history_item(1), "first line")
        self.assertEqual(readline.get_history_item(2), "second line")

        readline.replace_history_item(0, "replaced line")
        self.assertEqual(readline.get_history_item(0), None)
        self.assertEqual(readline.get_history_item(1), "replaced line")
        self.assertEqual(readline.get_history_item(2), "second line")

        self.assertEqual(readline.get_current_history_length(), 2)

        readline.remove_history_item(0)
        self.assertEqual(readline.get_history_item(0), None)
        self.assertEqual(readline.get_history_item(1), "second line")

        self.assertEqual(readline.get_current_history_length(), 1)

    @unittest.skipUnless(hasattr(readline, "append_history_file"),
                         "append_history not available")
    def test_write_read_append(self):
        hfile = tempfile.NamedTemporaryFile(delete=False)
        hfile.close()
        hfilename = hfile.name
        self.addCleanup(unlink, hfilename)

        # test write-clear-read == nop
        readline.clear_history()
        readline.add_history("first line")
        readline.add_history("second line")
        readline.write_history_file(hfilename)

        readline.clear_history()
        self.assertEqual(readline.get_current_history_length(), 0)

        readline.read_history_file(hfilename)
        self.assertEqual(readline.get_current_history_length(), 2)
        self.assertEqual(readline.get_history_item(1), "first line")
        self.assertEqual(readline.get_history_item(2), "second line")

        # test append
        readline.append_history_file(1, hfilename)
        readline.clear_history()
        readline.read_history_file(hfilename)
        self.assertEqual(readline.get_current_history_length(), 3)
        self.assertEqual(readline.get_history_item(1), "first line")
        self.assertEqual(readline.get_history_item(2), "second line")
        self.assertEqual(readline.get_history_item(3), "second line")

        # test 'no such file' behaviour
        os.unlink(hfilename)
        try:
            readline.append_history_file(1, hfilename)
        except FileNotFoundError:
            pass  # Some implementations return this error (libreadline).
        else:
            os.unlink(hfilename)  # Some create it anyways (libedit).
            # If the file wasn't created, unlink will fail.
        # We're just testing that one of the two expected behaviors happens
        # instead of an incorrect error.

        # write_history_file can create the target
        readline.write_history_file(hfilename)

        # Negative values should be disallowed
        with self.assertRaises(ValueError):
            readline.append_history_file(-42, hfilename)

        # See gh-122431, using the minimum signed integer value caused a segfault
        with self.assertRaises(ValueError):
            readline.append_history_file(-2147483648, hfilename)

    def test_nonascii_history(self):
        readline.clear_history()
        try:
            readline.add_history("entrée 1")
        except UnicodeEncodeError as err:
            self.skipTest("Locale cannot encode test data: " + format(err))
        readline.add_history("entrée 2")
        readline.replace_history_item(1, "entrée 22")
        readline.write_history_file(TESTFN)
        self.addCleanup(os.remove, TESTFN)
        readline.clear_history()
        readline.read_history_file(TESTFN)
        if is_editline:
            # An add_history() call seems to be required for get_history_
            # item() to register items from the file
            readline.add_history("dummy")
        self.assertEqual(readline.get_history_item(1), "entrée 1")
        self.assertEqual(readline.get_history_item(2), "entrée 22")

    def test_write_read_limited_history(self):
        previous_length = readline.get_history_length()
        self.addCleanup(readline.set_history_length, previous_length)

        readline.clear_history()
        readline.add_history("first line")
        readline.add_history("second line")
        readline.add_history("third line")

        readline.set_history_length(2)
        self.assertEqual(readline.get_history_length(), 2)
        readline.write_history_file(TESTFN)
        self.addCleanup(os.remove, TESTFN)

        readline.clear_history()
        self.assertEqual(readline.get_current_history_length(), 0)
        self.assertEqual(readline.get_history_length(), 2)

        readline.read_history_file(TESTFN)
        self.assertEqual(readline.get_history_item(1), "second line")
        self.assertEqual(readline.get_history_item(2), "third line")
        self.assertEqual(readline.get_history_item(3), None)

        # Readline seems to report an additional history element.
        self.assertIn(readline.get_current_history_length(), (2, 3))


class TestReadline(unittest.TestCase):

    @unittest.skipIf(readline._READLINE_VERSION < 0x0601 and not is_editline,
                     "not supported in this library version")
    def test_init(self):
        # Issue #19884: Ensure that the ANSI sequence "\033[1034h" is not
        # written into stdout when the readline module is imported and stdout
        # is redirected to a pipe.
        rc, stdout, stderr = assert_python_ok('-c', 'import readline',
                                              TERM='xterm-256color')
        self.assertEqual(stdout, b'')

    def test_backend(self):
        self.assertIn(readline.backend, ("readline", "editline"))

    auto_history_script = """\
import readline
readline.set_auto_history({})
input()
print("History length:", readline.get_current_history_length())
"""

    def test_auto_history_enabled(self):
        output = run_pty(self.auto_history_script.format(True))
        # bpo-44949: Sometimes, the newline character is not written at the
        # end, so don't expect it in the output.
        self.assertIn(b"History length: 1", output)

    def test_auto_history_disabled(self):
        output = run_pty(self.auto_history_script.format(False))
        # bpo-44949: Sometimes, the newline character is not written at the
        # end, so don't expect it in the output.
        self.assertIn(b"History length: 0", output)

    def test_set_complete_delims(self):
        script = textwrap.dedent("""
            import readline
            def complete(text, state):
                if state == 0 and text == "$":
                    return "$complete"
                return None
            if readline.backend == "editline":
                readline.parse_and_bind(r'bind "\\t" rl_complete')
            else:
                readline.parse_and_bind(r'"\\t": complete')
            readline.set_completer_delims(" \\t\\n")
            readline.set_completer(complete)
            print(input())
        """)

        output = run_pty(script, input=b"$\t\n")
        self.assertIn(b"$complete", output)

    def test_nonascii(self):
        loc = locale.setlocale(locale.LC_CTYPE, None)
        if loc in ('C', 'POSIX'):
            # bpo-29240: On FreeBSD, if the LC_CTYPE locale is C or POSIX,
            # writing and reading non-ASCII bytes into/from a TTY works, but
            # readline or ncurses ignores non-ASCII bytes on read.
            self.skipTest(f"the LC_CTYPE locale is {loc!r}")

        try:
            readline.add_history("\xEB\xEF")
        except UnicodeEncodeError as err:
            self.skipTest("Locale cannot encode test data: " + format(err))

        script = r"""import readline

is_editline = readline.backend == "editline"
inserted = "[\xEFnserted]"
macro = "|t\xEB[after]"
set_pre_input_hook = getattr(readline, "set_pre_input_hook", None)
if is_editline or not set_pre_input_hook:
    # The insert_line() call via pre_input_hook() does nothing with Editline,
    # so include the extra text that would have been inserted here
    macro = inserted + macro

if is_editline:
    readline.parse_and_bind(r'bind ^B ed-prev-char')
    readline.parse_and_bind(r'bind "\t" rl_complete')
    readline.parse_and_bind(r'bind -s ^A "{}"'.format(macro))
else:
    readline.parse_and_bind(r'Control-b: backward-char')
    readline.parse_and_bind(r'"\t": complete')
    readline.parse_and_bind(r'set disable-completion off')
    readline.parse_and_bind(r'set show-all-if-ambiguous off')
    readline.parse_and_bind(r'set show-all-if-unmodified off')
    readline.parse_and_bind(r'Control-a: "{}"'.format(macro))

def pre_input_hook():
    readline.insert_text(inserted)
    readline.redisplay()
if set_pre_input_hook:
    set_pre_input_hook(pre_input_hook)

def completer(text, state):
    if text == "t\xEB":
        if state == 0:
            print("text", ascii(text))
            print("line", ascii(readline.get_line_buffer()))
            print("indexes", readline.get_begidx(), readline.get_endidx())
            return "t\xEBnt"
        if state == 1:
            return "t\xEBxt"
    if text == "t\xEBx" and state == 0:
        return "t\xEBxt"
    return None
readline.set_completer(completer)

def display(substitution, matches, longest_match_length):
    print("substitution", ascii(substitution))
    print("matches", ascii(matches))
readline.set_completion_display_matches_hook(display)

print("result", ascii(input()))
print("history", ascii(readline.get_history_item(1)))
"""

        input = b"\x01"  # Ctrl-A, expands to "|t\xEB[after]"
        input += b"\x02" * len("[after]")  # Move cursor back
        input += b"\t\t"  # Display possible completions
        input += b"x\t"  # Complete "t\xEBx" -> "t\xEBxt"
        input += b"\r"
        output = run_pty(script, input)
        self.assertIn(b"text 't\\xeb'\r\n", output)
        self.assertIn(b"line '[\\xefnserted]|t\\xeb[after]'\r\n", output)
        if sys.platform == "darwin" or not is_editline:
            self.assertIn(b"indexes 11 13\r\n", output)
            # Non-macOS libedit does not handle non-ASCII bytes
            # the same way and generates character indices
            # rather than byte indices via get_begidx() and
            # get_endidx().  Ex: libedit2 3.1-20191231-2 on Debian
            # winds up with "indexes 10 12".  Stemming from the
            # start and end values calls back into readline.c's
            # rl_attempted_completion_function = flex_complete with:
            # (11, 13) instead of libreadline's (12, 15).

        if not is_editline and hasattr(readline, "set_pre_input_hook"):
            self.assertIn(b"substitution 't\\xeb'\r\n", output)
            self.assertIn(b"matches ['t\\xebnt', 't\\xebxt']\r\n", output)
        expected = br"'[\xefnserted]|t\xebxt[after]'"
        self.assertIn(b"result " + expected + b"\r\n", output)
        # bpo-45195: Sometimes, the newline character is not written at the
        # end, so don't expect it in the output.
        self.assertIn(b"history " + expected, output)

    # We have 2 reasons to skip this test:
    # - readline: history size was added in 6.0
    #   See https://cnswww.cns.cwru.edu/php/chet/readline/CHANGES
    # - editline: history size is broken on OS X 10.11.6.
    #   Newer versions were not tested yet.
    @unittest.skipIf(readline._READLINE_VERSION < 0x600,
                     "this readline version does not support history-size")
    @unittest.skipIf(is_editline,
                     "editline history size configuration is broken")
    def test_history_size(self):
        history_size = 10
        with temp_dir() as test_dir:
            inputrc = os.path.join(test_dir, "inputrc")
            with open(inputrc, "wb") as f:
                f.write(b"set history-size %d\n" % history_size)

            history_file = os.path.join(test_dir, "history")
            with open(history_file, "wb") as f:
                # history_size * 2 items crashes readline
                data = b"".join(b"item %d\n" % i
                                for i in range(history_size * 2))
                f.write(data)

            script = """
import os
import readline

history_file = os.environ["HISTORY_FILE"]
readline.read_history_file(history_file)
input()
readline.write_history_file(history_file)
"""

            env = dict(os.environ)
            env["INPUTRC"] = inputrc
            env["HISTORY_FILE"] = history_file

            run_pty(script, input=b"last input\r", env=env)

            with open(history_file, "rb") as f:
                lines = f.readlines()
            self.assertEqual(len(lines), history_size)
            self.assertEqual(lines[-1].strip(), b"last input")

    @requires_working_threading()
    def test_gh123321_threadsafe(self):
        """gh-123321: readline should be thread-safe and not crash"""
        script = textwrap.dedent(r"""
            import threading
            from test.support.threading_helper import join_thread

            def func():
                input()

            thread1 = threading.Thread(target=func)
            thread2 = threading.Thread(target=func)
            thread1.start()
            thread2.start()
            join_thread(thread1)
            join_thread(thread2)
            print("done")
        """)

        output = run_pty(script, input=b"input1\rinput2\r")

        self.assertIn(b"done", output)


    def test_write_read_limited_history(self):
        previous_length = readline.get_history_length()
        self.addCleanup(readline.set_history_length, previous_length)

        readline.add_history("first line")
        readline.add_history("second line")
        readline.add_history("third line")

        readline.set_history_length(2)
        self.assertEqual(readline.get_history_length(), 2)
        readline.write_history_file(TESTFN)
        self.addCleanup(os.remove, TESTFN)

        readline.read_history_file(TESTFN)
        # Without clear_history() there's no good way to test if
        # the correct entries are present (we're combining history limiting and
        # possible deduplication with arbitrary previous content).
        # So, we've only tested that the read did not fail.
        # See TestHistoryManipulation for the full test.


@unittest.skipUnless(support.Py_GIL_DISABLED, 'these tests can only possibly fail with GIL disabled')
class FreeThreadingTest(unittest.TestCase):
    @threading_helper.reap_threads
    @threading_helper.requires_working_threading()
    def test_free_threading(self):
        def completer_delims(b):
            b.wait()
            for _ in range(100):
                readline.get_completer_delims()
                readline.set_completer_delims(' \t\n`@#%^&*()=+[{]}\\|;:\'",<>?')
                readline.set_completer_delims(' \t\n`@#%^&*()=+[{]}\\|;:\'",<>?')
                readline.get_completer_delims()

        count   = 40
        barrier = threading.Barrier(count)
        threads = [threading.Thread(target=completer_delims, args=(barrier,)) for _ in range(count)]

        with threading_helper.start_threads(threads):
            pass


if __name__ == "__main__":
    unittest.main()