Create ``_config_initialization`` util and use in functional tests (#5591)

6 files changed, 111 insertions, 48 deletions

diff --git a/pylint/config/config_initialization.py b/pylint/config/config_initialization.py
new file mode 100644
index 000000000..46031bae3
--- /dev/null
+++ b/pylint/config/config_initialization.py
@@ -0,0 +1,75 @@
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
+
+import sys
+from typing import TYPE_CHECKING, List, Optional, Union
+
+from pylint import reporters
+from pylint.utils import utils
+
+if TYPE_CHECKING:
+    from pylint.lint import PyLinter
+
+
+def _config_initialization(
+    linter: "PyLinter",
+    args_list: List[str],
+    reporter: Union[reporters.BaseReporter, reporters.MultiReporter, None] = None,
+    config_file: Optional[str] = None,
+    verbose_mode: Optional[bool] = None,
+) -> List[str]:
+    """Parse all available options, read config files and command line arguments and
+    set options accordingly.
+    """
+
+    # Read the config file. The parser is stored on linter.cfgfile_parser
+    try:
+        linter.read_config_file(config_file=config_file, verbose=verbose_mode)
+    except OSError as ex:
+        print(ex, file=sys.stderr)
+        sys.exit(32)
+    config_parser = linter.cfgfile_parser
+
+    # Run init hook, if present, before loading plugins
+    if config_parser.has_option("MASTER", "init-hook"):
+        exec(  # pylint: disable=exec-used
+            utils._unquote(config_parser.get("MASTER", "init-hook"))
+        )
+
+    # Load plugins if specified in the config file
+    if config_parser.has_option("MASTER", "load-plugins"):
+        plugins = utils._splitstrip(config_parser.get("MASTER", "load-plugins"))
+        linter.load_plugin_modules(plugins)
+
+    # Now we can load file config, plugins (which can
+    # provide options) have been registered
+    linter.load_config_file()
+
+    if reporter:
+        # If a custom reporter is provided as argument, it may be overridden
+        # by file parameters, so re-set it here, but before command line
+        # parsing, so it's still overridable by command line option
+        linter.set_reporter(reporter)
+
+    # Load command line arguments
+    try:
+        args_list = linter.load_command_line_configuration(args_list)
+    except SystemExit as exc:
+        if exc.code == 2:  # bad options
+            exc.code = 32
+        raise
+
+    # args_list should now only be a list of files/directories to lint. All options have
+    # been removed from the list
+    if not args_list:
+        print(linter.help())
+        sys.exit(32)
+
+    # We have loaded configuration from config file and command line. Now, we can
+    # load plugin specific configuration.
+    linter.load_plugin_configuration()
+
+    # Now that plugins are loaded, get list of all fail_on messages, and enable them
+    linter.enable_fail_on_messages()
+
+    return args_list
diff --git a/pylint/lint/run.py b/pylint/lint/run.py
index a349298c1..a7539cd6a 100644
--- a/pylint/lint/run.py
+++ b/pylint/lint/run.py
@@ -6,6 +6,7 @@ import sys
 import warnings
 
 from pylint import __pkginfo__, extensions, interfaces
+from pylint.config.config_initialization import _config_initialization
 from pylint.constants import DEFAULT_PYLINT_HOME, OLD_DEFAULT_PYLINT_HOME, full_version
 from pylint.lint.pylinter import PyLinter
 from pylint.lint.utils import ArgumentPreprocessingError, preprocess_options
@@ -327,40 +328,8 @@ to search for configuration file.
         # read configuration
         linter.disable("I")
         linter.enable("c-extension-no-member")
-        try:
-            linter.read_config_file(verbose=self.verbose)
-        except OSError as ex:
-            print(ex, file=sys.stderr)
-            sys.exit(32)
 
-        config_parser = linter.cfgfile_parser
-        # run init hook, if present, before loading plugins
-        if config_parser.has_option("MASTER", "init-hook"):
-            cb_init_hook(
-                "init-hook", utils._unquote(config_parser.get("MASTER", "init-hook"))
-            )
-        # is there some additional plugins in the file configuration, in
-        if config_parser.has_option("MASTER", "load-plugins"):
-            plugins = utils._splitstrip(config_parser.get("MASTER", "load-plugins"))
-            linter.load_plugin_modules(plugins)
-        # now we can load file config and command line, plugins (which can
-        # provide options) have been registered
-        linter.load_config_file()
-
-        if reporter:
-            # If a custom reporter is provided as argument, it may be overridden
-            # by file parameters, so re-set it here, but before command line
-            # parsing, so it's still overridable by command line option
-            linter.set_reporter(reporter)
-        try:
-            args = linter.load_command_line_configuration(args)
-        except SystemExit as exc:
-            if exc.code == 2:  # bad options
-                exc.code = 32
-            raise
-        if not args:
-            print(linter.help())
-            sys.exit(32)
+        args = _config_initialization(linter, args, reporter, verbose_mode=self.verbose)
 
         if linter.config.jobs < 0:
             print(
@@ -378,13 +347,6 @@ to search for configuration file.
             elif linter.config.jobs == 0:
                 linter.config.jobs = _cpu_count()
 
-        # We have loaded configuration from config file and command line. Now, we can
-        # load plugin specific configuration.
-        linter.load_plugin_configuration()
-
-        # Now that plugins are loaded, get list of all fail_on messages, and enable them
-        linter.enable_fail_on_messages()
-
         if self._output:
             try:
                 with open(self._output, "w", encoding="utf-8") as output:
diff --git a/pylint/testutils/lint_module_test.py b/pylint/testutils/lint_module_test.py
index b7e1ffc67..e89f82ace 100644
--- a/pylint/testutils/lint_module_test.py
+++ b/pylint/testutils/lint_module_test.py
@@ -14,6 +14,7 @@ import pytest
 from _pytest.config import Config
 
 from pylint import checkers
+from pylint.config.config_initialization import _config_initialization
 from pylint.lint import PyLinter
 from pylint.message.message import Message
 from pylint.testutils.constants import _EXPECTED_RE, _OPERATORS, UPDATE_OPTION
@@ -24,7 +25,6 @@ from pylint.testutils.functional.test_file import (  # need to import from funct
 )
 from pylint.testutils.output_line import OutputLine
 from pylint.testutils.reporter_for_tests import FunctionalTestReporter
-from pylint.utils import utils
 
 MessageCounter = CounterType[Tuple[int, str]]
 
@@ -44,15 +44,14 @@ class LintModuleTest:
         self._linter.disable("locally-disabled")
         self._linter.disable("useless-suppression")
         try:
-            self._linter.read_config_file(test_file.option_file)
-            if self._linter.cfgfile_parser.has_option("MASTER", "load-plugins"):
-                plugins = utils._splitstrip(
-                    self._linter.cfgfile_parser.get("MASTER", "load-plugins")
-                )
-                self._linter.load_plugin_modules(plugins)
-            self._linter.load_config_file()
+            _config_initialization(
+                self._linter,
+                [test_file.source],
+                config_file=test_file.option_file,
+            )
         except NoFileError:
             pass
+
         self._test_file = test_file
         self._config = config
         self._check_end_position = (
diff --git a/tests/testutils/data/init_hook.py b/tests/testutils/data/init_hook.py
new file mode 100644
index 000000000..f16492d3a
--- /dev/null
+++ b/tests/testutils/data/init_hook.py
@@ -0,0 +1,3 @@
+"""This file should never be tested as the init-hook in the configuration
+file prevents the test runner from getting here.
+"""
diff --git a/tests/testutils/data/init_hook.rc b/tests/testutils/data/init_hook.rc
new file mode 100644
index 000000000..b0efa254b
--- /dev/null
+++ b/tests/testutils/data/init_hook.rc
@@ -0,0 +1,3 @@
+[MASTER]
+
+init-hook=raise RuntimeError
diff --git a/tests/testutils/test_functional_testutils.py b/tests/testutils/test_functional_testutils.py
new file mode 100644
index 000000000..c1e852e15
--- /dev/null
+++ b/tests/testutils/test_functional_testutils.py
@@ -0,0 +1,21 @@
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
+
+"""Tests for the functional test framework."""
+
+from pathlib import Path
+
+import pytest
+
+from pylint import testutils
+from pylint.testutils.functional import FunctionalTestFile
+
+HERE = Path(__file__).parent
+DATA_DIRECTORY = HERE / "data"
+
+
+def test_parsing_of_pylintrc_init_hook() -> None:
+    """Test that we correctly parse an init-hook in a settings file."""
+    with pytest.raises(RuntimeError):
+        test_file = FunctionalTestFile(str(DATA_DIRECTORY), "init_hook.py")
+        testutils.LintModuleTest(test_file)