config: inline _preparse

No that "preparse" phase is no longer a thing, with the removal of the
historic `pytest_cmdline_preparse` hook and `after_preparse` hack, let's
inline so we can see the full parse flow in linear code.

Author: bluetech

src/_pytest/config/__init__.py

@@ -1355,92 +1355,6 @@ def _decide_args(
                 result = [str(invocation_dir)]
         return result, source
 
-    def _preparse(self, args: list[str], addopts: bool = True) -> None:
-        if addopts:
-            env_addopts = os.environ.get("PYTEST_ADDOPTS", "")
-            if len(env_addopts):
-                args[:] = (
-                    self._validate_args(shlex.split(env_addopts), "via PYTEST_ADDOPTS")
-                    + args
-                )
-
-        ns = self._parser.parse_known_args(args, namespace=copy.copy(self.option))
-        rootpath, inipath, inicfg, ignored_config_files = determine_setup(
-            inifile=ns.inifilename,
-            override_ini=ns.override_ini,
-            args=ns.file_or_dir,
-            rootdir_cmd_arg=ns.rootdir or None,
-            invocation_dir=self.invocation_params.dir,
-        )
-        self._rootpath = rootpath
-        self._inipath = inipath
-        self._ignored_config_files = ignored_config_files
-        self.inicfg = inicfg
-        self._parser.extra_info["rootdir"] = str(self.rootpath)
-        self._parser.extra_info["inifile"] = str(self.inipath)
-        self._parser.addini("addopts", "Extra command line options", "args")
-        self._parser.addini("minversion", "Minimally required pytest version")
-        self._parser.addini(
-            "pythonpath", type="paths", help="Add paths to sys.path", default=[]
-        )
-        self._parser.addini(
-            "required_plugins",
-            "Plugins that must be present for pytest to run",
-            type="args",
-            default=[],
-        )
-
-        if addopts:
-            args[:] = (
-                self._validate_args(self.getini("addopts"), "via addopts config") + args
-            )
-
-        self.known_args_namespace = self._parser.parse_known_args(
-            args, namespace=copy.copy(self.option)
-        )
-        self._checkversion()
-        self._consider_importhook()
-        self._configure_python_path()
-        self.pluginmanager.consider_preparse(args, exclude_only=False)
-        if (
-            not os.environ.get("PYTEST_DISABLE_PLUGIN_AUTOLOAD")
-            and not self.known_args_namespace.disable_plugin_autoload
-        ):
-            # Autoloading from distribution package entry point has
-            # not been disabled.
-            self.pluginmanager.load_setuptools_entrypoints("pytest11")
-        # Otherwise only plugins explicitly specified in PYTEST_PLUGINS
-        # are going to be loaded.
-        self.pluginmanager.consider_env()
-
-        self.known_args_namespace = self._parser.parse_known_args(
-            args, namespace=copy.copy(self.known_args_namespace)
-        )
-
-        self._validate_plugins()
-        self._warn_about_skipped_plugins()
-
-        if self.known_args_namespace.confcutdir is None:
-            if self.inipath is not None:
-                confcutdir = str(self.inipath.parent)
-            else:
-                confcutdir = str(self.rootpath)
-            self.known_args_namespace.confcutdir = confcutdir
-        try:
-            self.hook.pytest_load_initial_conftests(
-                early_config=self, args=args, parser=self._parser
-            )
-        except ConftestImportFailure as e:
-            if self.known_args_namespace.help or self.known_args_namespace.version:
-                # we don't want to prevent --help/--version to work
-                # so just let it pass and print a warning at the end
-                self.issue_config_time_warning(
-                    PytestConfigWarning(f"could not load initial conftests: {e.path}"),
-                    stacklevel=2,
-                )
-            else:
-                raise
-
     @hookimpl(wrapper=True)
     def pytest_collection(self) -> Generator[None, object, object]:
         # Validate invalid configuration keys after collection is done so we
@@ -1524,14 +1438,102 @@ def parse(self, args: list[str], addopts: bool = True) -> None:
         assert self.args == [], (
             "can only parse cmdline args at most once per Config object"
         )
+
         self.hook.pytest_addhooks.call_historic(
             kwargs=dict(pluginmanager=self.pluginmanager)
         )
-        self._preparse(args, addopts=addopts)
+
+        if addopts:
+            env_addopts = os.environ.get("PYTEST_ADDOPTS", "")
+            if len(env_addopts):
+                args[:] = (
+                    self._validate_args(shlex.split(env_addopts), "via PYTEST_ADDOPTS")
+                    + args
+                )
+
+        ns = self._parser.parse_known_args(args, namespace=copy.copy(self.option))
+        rootpath, inipath, inicfg, ignored_config_files = determine_setup(
+            inifile=ns.inifilename,
+            override_ini=ns.override_ini,
+            args=ns.file_or_dir,
+            rootdir_cmd_arg=ns.rootdir or None,
+            invocation_dir=self.invocation_params.dir,
+        )
+        self._rootpath = rootpath
+        self._inipath = inipath
+        self._ignored_config_files = ignored_config_files
+        self.inicfg = inicfg
+        self._parser.extra_info["rootdir"] = str(self.rootpath)
+        self._parser.extra_info["inifile"] = str(self.inipath)
+
+        self._parser.addini("addopts", "Extra command line options", "args")
+        self._parser.addini("minversion", "Minimally required pytest version")
+        self._parser.addini(
+            "pythonpath", type="paths", help="Add paths to sys.path", default=[]
+        )
+        self._parser.addini(
+            "required_plugins",
+            "Plugins that must be present for pytest to run",
+            type="args",
+            default=[],
+        )
+
+        if addopts:
+            args[:] = (
+                self._validate_args(self.getini("addopts"), "via addopts config") + args
+            )
+
+        self.known_args_namespace = self._parser.parse_known_args(
+            args, namespace=copy.copy(self.option)
+        )
+        self._checkversion()
+        self._consider_importhook()
+        self._configure_python_path()
+        self.pluginmanager.consider_preparse(args, exclude_only=False)
+        if (
+            not os.environ.get("PYTEST_DISABLE_PLUGIN_AUTOLOAD")
+            and not self.known_args_namespace.disable_plugin_autoload
+        ):
+            # Autoloading from distribution package entry point has
+            # not been disabled.
+            self.pluginmanager.load_setuptools_entrypoints("pytest11")
+        # Otherwise only plugins explicitly specified in PYTEST_PLUGINS
+        # are going to be loaded.
+        self.pluginmanager.consider_env()
+
+        self.known_args_namespace = self._parser.parse_known_args(
+            args, namespace=copy.copy(self.known_args_namespace)
+        )
+
+        self._validate_plugins()
+        self._warn_about_skipped_plugins()
+
+        if self.known_args_namespace.confcutdir is None:
+            if self.inipath is not None:
+                confcutdir = str(self.inipath.parent)
+            else:
+                confcutdir = str(self.rootpath)
+            self.known_args_namespace.confcutdir = confcutdir
+        try:
+            self.hook.pytest_load_initial_conftests(
+                early_config=self, args=args, parser=self._parser
+            )
+        except ConftestImportFailure as e:
+            if self.known_args_namespace.help or self.known_args_namespace.version:
+                # we don't want to prevent --help/--version to work
+                # so just let it pass and print a warning at the end
+                self.issue_config_time_warning(
+                    PytestConfigWarning(f"could not load initial conftests: {e.path}"),
+                    stacklevel=2,
+                )
+            else:
+                raise
+
         try:
             self._parser.parse(args, namespace=self.option)
         except PrintHelp:
             return
+
         self.args, self.args_source = self._decide_args(
             args=getattr(self.option, FILE_OR_DIR),
             pyargs=self.option.pyargs,

testing/test_config.py

@@ -2276,7 +2276,7 @@ def test_addopts_before_initini(
         cache_dir = ".custom_cache"
         monkeypatch.setenv("PYTEST_ADDOPTS", f"-o cache_dir={cache_dir}")
         config = _config_for_test
-        config._preparse([], addopts=True)
+        config.parse([], addopts=True)
         assert config.inicfg.get("cache_dir") == ConfigValue(
             cache_dir, origin="override", mode="ini"
         )
@@ -2288,7 +2288,7 @@ def test_addopts_from_env_not_concatenated(
         monkeypatch.setenv("PYTEST_ADDOPTS", "-o")
         config = _config_for_test
         with pytest.raises(UsageError) as excinfo:
-            config._preparse(["cache_dir=ignored"], addopts=True)
+            config.parse(["cache_dir=ignored"], addopts=True)
         assert (
             "error: argument -o/--override-ini: expected one argument"
             in excinfo.value.args[0]
@@ -2317,7 +2317,7 @@ def test_override_ini_does_not_contain_paths(
     ) -> None:
         """Check that -o no longer swallows all options after it (#3103)"""
         config = _config_for_test
-        config._preparse(["-o", "cache_dir=/cache", "/some/test/path"])
+        config.parse(["-o", "cache_dir=/cache", "/some/test/path"])
         assert config.inicfg.get("cache_dir") == ConfigValue(
             "/cache", origin="override", mode="ini"
         )

testing/test_warnings.py

@@ -742,10 +742,8 @@ def test_issue4445_rewrite(self, pytester: Pytester, capwarn) -> None:
         assert func == "<module>"  # the above conftest.py
         assert lineno == 4
 
-    def test_issue4445_preparse(self, pytester: Pytester, capwarn) -> None:
-        """#4445: Make sure the warning points to a reasonable location
-        See origin of _issue_warning_captured at: _pytest.config.__init__.py:910
-        """
+    def test_issue4445_initial_conftest(self, pytester: Pytester, capwarn) -> None:
+        """#4445: Make sure the warning points to a reasonable location."""
         pytester.makeconftest(
             """
             import nothing
@@ -761,7 +759,7 @@ def test_issue4445_preparse(self, pytester: Pytester, capwarn) -> None:
 
         assert "could not load initial conftests" in str(warning.message)
         assert f"config{os.sep}__init__.py" in file
-        assert func == "_preparse"
+        assert func == "parse"
 
     @pytest.mark.filterwarnings("default")
     def test_conftest_warning_captured(self, pytester: Pytester) -> None: