Add deprecate_python fixture to easily deprecate python versions

pip usually emits a warning and tests have to be adapted

tests/conftest.py

@@ -277,7 +277,7 @@ def with_wheel(virtualenv, wheel_install):
 
 
 @pytest.fixture
-def script(tmpdir, virtualenv):
+def script(tmpdir, virtualenv, deprecated_python):
     """
     Return a PipTestEnvironment which is unique to each test function and
     will execute all commands inside of the unique virtual environment for this
@@ -301,6 +301,9 @@ def script(tmpdir, virtualenv):
         # PipTestEnvironment needs to capture and assert against temp
         capture_temp=True,
         assert_no_temp=True,
+
+        # Deprecated python versions produce an extra deprecation warning
+        pip_expect_stderr=deprecated_python,
     )
 
 
@@ -341,3 +344,9 @@ class InMemoryPip(object):
 @pytest.fixture
 def in_memory_pip():
     return InMemoryPip()
+
+
+@pytest.fixture
+def deprecated_python():
+    """Used to indicate wheither pip deprecated this python version"""
+    return False

tests/functional/test_completion.py

@@ -283,10 +283,10 @@ def test_completion_path_after_option(script, data):
 
 
 @pytest.mark.parametrize('flag', ['--bash', '--zsh', '--fish'])
-def test_completion_uses_same_executable_name(script, flag):
-    expect_stderr = sys.version_info[:2] == (3, 3)
+def test_completion_uses_same_executable_name(script, flag, deprecated_python):
     executable_name = 'pip{}'.format(sys.version_info[0])
+    # Deprecated python versions produce an extra deprecation warning
     result = script.run(
-        executable_name, 'completion', flag, expect_stderr=expect_stderr
+        executable_name, 'completion', flag, expect_stderr=deprecated_python,
     )
     assert executable_name in result.stdout

tests/functional/test_freeze.py

@@ -138,7 +138,7 @@ def test_freeze_editable_not_vcs(script, tmpdir):
 
 
 @pytest.mark.git
-def test_freeze_editable_git_with_no_remote(script, tmpdir):
+def test_freeze_editable_git_with_no_remote(script, tmpdir, deprecated_python):
     """
     Test an editable Git install with no remote url.
     """
@@ -146,7 +146,8 @@ def test_freeze_editable_git_with_no_remote(script, tmpdir):
     script.pip('install', '-e', pkg_path)
     result = script.pip('freeze')
 
-    assert result.stderr == ''
+    if not deprecated_python:
+        assert result.stderr == ''
 
     # We need to apply os.path.normcase() to the path since that is what
     # the freeze code does.
@@ -460,7 +461,8 @@ _freeze_req_opts = textwrap.dedent("""\
 """)
 
 
-def test_freeze_with_requirement_option_file_url_egg_not_installed(script):
+def test_freeze_with_requirement_option_file_url_egg_not_installed(
+        script, deprecated_python):
     """
     Test "freeze -r requirements.txt" with a local file URL whose egg name
     is not installed.
@@ -477,7 +479,10 @@ def test_freeze_with_requirement_option_file_url_egg_not_installed(script):
         'Requirement file [requirements.txt] contains {}, but package '
         "'Does.Not-Exist' is not installed\n"
     ).format(url)
-    assert result.stderr == expected_err
+    if deprecated_python:
+        assert expected_err in result.stderr
+    else:
+        assert expected_err == result.stderr
 
 
 def test_freeze_with_requirement_option(script):

tests/functional/test_install.py

@@ -37,7 +37,8 @@ def test_pep518_uses_build_env(script, data, common_wheels, command, variant):
     )
 
 
-def test_pep518_build_env_uses_same_pip(script, data, pip_src, common_wheels):
+def test_pep518_build_env_uses_same_pip(
+        script, data, pip_src, common_wheels, deprecated_python):
     """Ensure the subprocess call to pip for installing the
     build dependencies is using the same version of pip.
     """
@@ -47,6 +48,7 @@ def test_pep518_build_env_uses_same_pip(script, data, pip_src, common_wheels):
         'python', pip_src / 'src/pip', 'install', '--no-index',
         '-f', common_wheels, '-f', data.packages,
         data.src.join("pep518-3.0"),
+        expect_stderr=deprecated_python,
     )
 
 
@@ -162,8 +164,8 @@ def test_pep518_forkbombs(script, data, common_wheels, command, package):
 
 
 @pytest.mark.network
-def test_pip_second_command_line_interface_works(script, pip_src, data,
-                                                 common_wheels):
+def test_pip_second_command_line_interface_works(
+        script, pip_src, data, common_wheels, deprecated_python):
     """
     Check if ``pip<PYVERSION>`` commands behaves equally
     """
@@ -171,7 +173,7 @@ def test_pip_second_command_line_interface_works(script, pip_src, data,
     script.pip_install_local('-f', common_wheels, pip_src)
     # On old versions of Python, urllib3/requests will raise a warning about
     # the lack of an SSLContext.
-    kwargs = {}
+    kwargs = {'expect_stderr': deprecated_python}
     if pyversion_tuple < (2, 7, 9):
         kwargs['expect_stderr'] = True
 

tests/functional/test_install_check.py

@@ -1,11 +1,14 @@
 from tests.lib import create_test_package_with_setup
 
 
-def matches_expected_lines(string, expected_lines):
-    return set(string.splitlines()) == set(expected_lines)
+def matches_expected_lines(string, expected_lines, exact=True):
+    if exact:
+        return set(string.splitlines()) == set(expected_lines)
+    # If not exact, check that all expected lines are present
+    return set(expected_lines) <= set(string.splitlines())
 
 
-def test_check_install_canonicalization(script):
+def test_check_install_canonicalization(script, deprecated_python):
     pkga_path = create_test_package_with_setup(
         script,
         name='pkgA',
@@ -33,7 +36,9 @@ def test_check_install_canonicalization(script):
     expected_lines = [
         "pkga 1.0 requires SPECIAL.missing, which is not installed.",
     ]
-    assert matches_expected_lines(result.stderr, expected_lines)
+    # Deprecated python versions produce an extra warning on stderr
+    assert matches_expected_lines(
+        result.stderr, expected_lines, exact=not deprecated_python)
     assert result.returncode == 0
 
     # Install the second missing package and expect that there is no warning
@@ -42,7 +47,8 @@ def test_check_install_canonicalization(script):
     result = script.pip(
         'install', '--no-index', special_path, '--quiet',
     )
-    assert matches_expected_lines(result.stderr, [])
+    assert matches_expected_lines(
+        result.stderr, [], exact=not deprecated_python)
     assert result.returncode == 0
 
     # Double check that all errors are resolved in the end
@@ -54,7 +60,8 @@ def test_check_install_canonicalization(script):
     assert result.returncode == 0
 
 
-def test_check_install_does_not_warn_for_out_of_graph_issues(script):
+def test_check_install_does_not_warn_for_out_of_graph_issues(
+        script, deprecated_python):
     pkg_broken_path = create_test_package_with_setup(
         script,
         name='broken',
@@ -74,7 +81,9 @@ def test_check_install_does_not_warn_for_out_of_graph_issues(script):
 
     # Install a package without it's dependencies
     result = script.pip('install', '--no-index', pkg_broken_path, '--no-deps')
-    assert matches_expected_lines(result.stderr, [])
+    # Deprecated python versions produce an extra warning on stderr
+    assert matches_expected_lines(
+        result.stderr, [], exact=not deprecated_python)
 
     # Install conflict package
     result = script.pip(
@@ -86,14 +95,15 @@ def test_check_install_does_not_warn_for_out_of_graph_issues(script):
             "broken 1.0 has requirement conflict<1.0, but "
             "you'll have conflict 1.0 which is incompatible."
         ),
-    ])
+    ], exact=not deprecated_python)
 
     # Install unrelated package
     result = script.pip(
         'install', '--no-index', pkg_unrelated_path, '--quiet',
     )
     # should not warn about broken's deps when installing unrelated package
-    assert matches_expected_lines(result.stderr, [])
+    assert matches_expected_lines(
+        result.stderr, [], exact=not deprecated_python)
 
     result = script.pip('check', expect_error=True)
     expected_lines = [

tests/lib/__init__.py

@@ -323,6 +323,10 @@ class PipTestEnvironment(TestFileEnvironment):
         environ["PYTHONIOENCODING"] = "UTF-8"
         kwargs["environ"] = environ
 
+        # Whether all pip invocations should expect stderr
+        # (useful for Python version deprecation)
+        self.pip_expect_stderr = kwargs.pop('pip_expect_stderr', None)
+
         # Call the TestFileEnvironment __init__
         super(PipTestEnvironment, self).__init__(base_path, *args, **kwargs)
 
@@ -375,6 +379,8 @@ class PipTestEnvironment(TestFileEnvironment):
         )
 
     def pip(self, *args, **kwargs):
+        if self.pip_expect_stderr:
+            kwargs['expect_stderr'] = True
         # On old versions of Python, urllib3/requests will raise a warning
         # about the lack of an SSLContext. Expect it when running commands
         # that will touch the outside world.