Remove dependency on the external module mock

[mcepl]

Since Python 3.3 mock is present the Python’s standard library, so it is not necessary to use external module. This patch removes the need of using it:

--- a/tests/lib/server.py
+++ b/tests/lib/server.py
@@ -5,7 +5,7 @@ import threading
 from contextlib import contextmanager
 from textwrap import dedent
 
-from mock import Mock
+from unittest.mock import Mock
 from pip._vendor.contextlib2 import nullcontext
 from werkzeug.serving import WSGIRequestHandler
 from werkzeug.serving import make_server as _make_server
--- a/tests/unit/test_base_command.py
+++ b/tests/unit/test_base_command.py
@@ -3,7 +3,7 @@ import os
 import time
 
 import pytest
-from mock import Mock, patch
+from unittest.mock import Mock, patch
 
 from pip._internal.cli.base_command import Command
 from pip._internal.cli.status_codes import SUCCESS
--- a/tests/unit/test_commands.py
+++ b/tests/unit/test_commands.py
@@ -1,5 +1,5 @@
 import pytest
-from mock import patch
+from unittest.mock import patch
 
 from pip._internal.cli.req_command import (
     IndexGroupCommand,
--- a/tests/unit/test_network_cache.py
+++ b/tests/unit/test_network_cache.py
@@ -1,7 +1,7 @@
 import os
 
 import pytest
-from mock import Mock
+from unittest.mock import Mock
 from pip._vendor.cachecontrol.caches import FileCache
 
 from pip._internal.network.cache import SafeFileCache
--- a/tests/unit/test_req_file.py
+++ b/tests/unit/test_req_file.py
@@ -5,7 +5,7 @@ import subprocess
 import textwrap
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 from pip._vendor.six import PY2
 from pretend import stub
 
--- a/tests/unit/test_resolution_legacy_resolver.py
+++ b/tests/unit/test_resolution_legacy_resolver.py
@@ -1,6 +1,6 @@
 import logging
 
-import mock
+import unittest.mock
 import pytest
 from pip._vendor import pkg_resources
 
--- a/tests/unit/test_target_python.py
+++ b/tests/unit/test_target_python.py
@@ -1,5 +1,5 @@
 import pytest
-from mock import patch
+from unittest.mock import patch
 
 from pip._internal.models.target_python import TargetPython
 from tests.lib import CURRENT_PY_VERSION_INFO, pyversion
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -14,7 +14,7 @@ import time
 from io import BytesIO
 
 import pytest
-from mock import Mock, patch
+from unittest.mock import Mock, patch
 
 from pip._internal.exceptions import (
     HashMismatch,
--- a/tests/unit/test_utils_compatibility_tags.py
+++ b/tests/unit/test_utils_compatibility_tags.py
@@ -1,7 +1,7 @@
 import sysconfig
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 
 from pip._internal.utils import compatibility_tags
 
--- a/tests/unit/test_vcs.py
+++ b/tests/unit/test_vcs.py
@@ -2,7 +2,7 @@ import os
 from unittest import TestCase
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 from pip._vendor.packaging.version import parse as parse_version
 
 from pip._internal.exceptions import BadCommand, InstallationError
--- a/tests/unit/test_wheel.py
+++ b/tests/unit/test_wheel.py
@@ -8,7 +8,7 @@ import textwrap
 from email import message_from_string
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 from pip._vendor.packaging.requirements import Requirement
 
 from pip._internal.exceptions import InstallationError
--- a/tests/unit/test_wheel_builder.py
+++ b/tests/unit/test_wheel_builder.py
@@ -1,7 +1,7 @@
 import logging
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 
 from pip._internal import wheel_builder
 from pip._internal.models.link import Link
--- a/tests/functional/test_help.py
+++ b/tests/functional/test_help.py
@@ -1,5 +1,5 @@
 import pytest
-from mock import Mock
+from unittest.mock import Mock
 
 from pip._internal.cli.status_codes import ERROR, SUCCESS
 from pip._internal.commands import commands_dict, create_command
--- a/tests/unit/resolution_resolvelib/test_resolver.py
+++ b/tests/unit/resolution_resolvelib/test_resolver.py
@@ -1,4 +1,4 @@
-import mock
+import unittest.mock as mock
 import pytest
 from pip._vendor.packaging.utils import canonicalize_name
 from pip._vendor.resolvelib.resolvers import Result
--- a/tests/unit/test_check.py
+++ b/tests/unit/test_check.py
@@ -1,7 +1,7 @@
 """Unit Tests for pip's dependency checking logic
 """
 
-import mock
+import unittest.mock
 
 from pip._internal.operations import check
 
--- a/tests/unit/test_collector.py
+++ b/tests/unit/test_collector.py
@@ -4,10 +4,10 @@ import re
 import uuid
 from textwrap import dedent
 
-import mock
+import unittest.mock as mock
 import pretend
 import pytest
-from mock import Mock, patch
+from unittest.mock import Mock, patch
 from pip._vendor import html5lib, requests
 from pip._vendor.six.moves.urllib import request as urllib_request
 
--- a/tests/unit/test_command_install.py
+++ b/tests/unit/test_command_install.py
@@ -1,7 +1,7 @@
 import errno
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 from pip._vendor.packaging.requirements import Requirement
 
 from pip._internal.commands.install import (
--- a/tests/unit/test_configuration.py
+++ b/tests/unit/test_configuration.py
@@ -4,7 +4,7 @@
 import os
 
 import pytest
-from mock import MagicMock
+from unittest.mock import MagicMock
 
 from pip._internal.configuration import get_configuration_files, kinds
 from pip._internal.exceptions import ConfigurationError
--- a/tests/unit/test_direct_url_helpers.py
+++ b/tests/unit/test_direct_url_helpers.py
@@ -1,6 +1,6 @@
 from functools import partial
 
-from mock import MagicMock, patch
+from unittest.mock import MagicMock, patch
 
 from pip._internal.models.direct_url import (
     DIRECT_URL_METADATA_NAME,
--- a/tests/unit/test_finder.py
+++ b/tests/unit/test_finder.py
@@ -2,7 +2,7 @@ import logging
 import sys
 
 import pytest
-from mock import Mock, patch
+from unittest.mock import Mock, patch
 from pip._vendor.packaging.specifiers import SpecifierSet
 from pip._vendor.packaging.tags import Tag
 from pkg_resources import parse_version
--- a/tests/unit/test_locations.py
+++ b/tests/unit/test_locations.py
@@ -9,7 +9,7 @@ import sys
 import tempfile
 
 import pytest
-from mock import Mock
+from unittest.mock import Mock
 
 from pip._internal.locations import distutils_scheme
 
--- a/tests/unit/test_logging.py
+++ b/tests/unit/test_logging.py
@@ -5,7 +5,7 @@ import time
 from threading import Thread
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 from pip._vendor.six import PY2
 
 from pip._internal.utils.logging import (
--- a/tests/unit/test_operations_prepare.py
+++ b/tests/unit/test_operations_prepare.py
@@ -4,7 +4,7 @@ from shutil import rmtree
 from tempfile import mkdtemp
 
 import pytest
-from mock import Mock, patch
+from unittest.mock import Mock, patch
 
 from pip._internal.exceptions import HashMismatch
 from pip._internal.models.link import Link
--- a/tests/unit/test_req.py
+++ b/tests/unit/test_req.py
@@ -6,7 +6,7 @@ import tempfile
 from functools import partial
 
 import pytest
-from mock import patch
+from unittest.mock import patch
 from pip._vendor import pkg_resources
 from pip._vendor.packaging.markers import Marker
 from pip._vendor.packaging.requirements import Requirement
--- a/tests/unit/test_req_uninstall.py
+++ b/tests/unit/test_req_uninstall.py
@@ -2,7 +2,7 @@ import os
 import sys
 
 import pytest
-from mock import Mock
+from unittest.mock import Mock
 
 import pip._internal.req.req_uninstall
 from pip._internal.req.req_uninstall import (

[pradyunsg]

Thanks for filing this issue!

The reason for the external dependency is that, as of right now, pip's master branch still supports Python 2.

[pradyunsg]

Closing since this is covered by #8802.