feat: add warning when pytest.ini and pyproject.toml are present

AUTHORS

@@ -403,6 +403,7 @@ Sadra Barikbin
 Saiprasad Kale
 Samuel Colvin
 Samuel Dion-Girardeau
+Samuel Gaist
 Samuel Jirovec
 Samuel Searles-Bryant
 Samuel Therrien (Avasam)

changelog/13330.improvement.rst

@@ -0,0 +1,3 @@
+Having both ``pytest.ini`` and ``pyproject.toml`` will now print a warning to make it clearer to the user that the former takes precedence over the latter.
+
+-- by :user:`sgaist`

src/_pytest/config/__init__.py

@@ -1107,6 +1107,14 @@ def inipath(self) -> pathlib.Path | None:
         """
         return self._inipath
 
+    @property
+    def should_warn(self) -> bool:
+        """Whether a warning should be emitted for the configuration.
+
+        .. versionadded:: 8.6
+        """
+        return self._should_warn
+
     def add_cleanup(self, func: Callable[[], None]) -> None:
         """Add a function to be called when the config object gets out of
         use (usually coinciding with pytest_unconfigure).
@@ -1242,14 +1250,15 @@ def _initini(self, args: Sequence[str]) -> None:
         ns, unknown_args = self._parser.parse_known_and_unknown_args(
             args, namespace=copy.copy(self.option)
         )
-        rootpath, inipath, inicfg = determine_setup(
+        rootpath, inipath, inicfg, should_warn = determine_setup(
             inifile=ns.inifilename,
             args=ns.file_or_dir + unknown_args,
             rootdir_cmd_arg=ns.rootdir or None,
             invocation_dir=self.invocation_params.dir,
         )
         self._rootpath = rootpath
         self._inipath = inipath
+        self._should_warn = should_warn
         self.inicfg = inicfg
         self._parser.extra_info["rootdir"] = str(self.rootpath)
         self._parser.extra_info["inifile"] = str(self.inipath)

src/_pytest/config/findpaths.py

@@ -91,7 +91,7 @@ def make_scalar(v: object) -> str | list[str]:
 def locate_config(
     invocation_dir: Path,
     args: Iterable[Path],
-) -> tuple[Path | None, Path | None, ConfigDict]:
+) -> tuple[Path | None, Path | None, ConfigDict, bool]:
     """Search in the list of arguments for a valid ini-file for pytest,
     and return a tuple of (rootdir, inifile, cfg-dict)."""
     config_names = [
@@ -105,6 +105,7 @@ def locate_config(
     if not args:
         args = [invocation_dir]
     found_pyproject_toml: Path | None = None
+
     for arg in args:
         argpath = absolutepath(arg)
         for base in (argpath, *argpath.parents):
@@ -115,10 +116,17 @@ def locate_config(
                         found_pyproject_toml = p
                     ini_config = load_config_dict_from_file(p)
                     if ini_config is not None:
-                        return base, p, ini_config
+                        should_warn = False
+                        if ".ini" in p.suffixes:
+                            pyproject = base / "pyproject.toml"
+                            if pyproject.is_file():
+                                should_warn = (
+                                    load_config_dict_from_file(pyproject) is not None
+                                )
+                        return base, p, ini_config, should_warn
     if found_pyproject_toml is not None:
-        return found_pyproject_toml.parent, found_pyproject_toml, {}
-    return None, None, {}
+        return found_pyproject_toml.parent, found_pyproject_toml, {}, False
+    return None, None, {}, False
 
 
 def get_common_ancestor(
@@ -178,7 +186,7 @@ def determine_setup(
     args: Sequence[str],
     rootdir_cmd_arg: str | None,
     invocation_dir: Path,
-) -> tuple[Path, Path | None, ConfigDict]:
+) -> tuple[Path, Path | None, ConfigDict, bool]:
     """Determine the rootdir, inifile and ini configuration values from the
     command line arguments.
 
@@ -193,6 +201,7 @@ def determine_setup(
     """
     rootdir = None
     dirs = get_dirs_from_args(args)
+    should_warn = False
     if inifile:
         inipath_ = absolutepath(inifile)
         inipath: Path | None = inipath_
@@ -201,15 +210,17 @@ def determine_setup(
             rootdir = inipath_.parent
     else:
         ancestor = get_common_ancestor(invocation_dir, dirs)
-        rootdir, inipath, inicfg = locate_config(invocation_dir, [ancestor])
+        rootdir, inipath, inicfg, should_warn = locate_config(
+            invocation_dir, [ancestor]
+        )
         if rootdir is None and rootdir_cmd_arg is None:
             for possible_rootdir in (ancestor, *ancestor.parents):
                 if (possible_rootdir / "setup.py").is_file():
                     rootdir = possible_rootdir
                     break
             else:
                 if dirs != [ancestor]:
-                    rootdir, inipath, inicfg = locate_config(invocation_dir, dirs)
+                    rootdir, inipath, inicfg, _ = locate_config(invocation_dir, dirs)
                 if rootdir is None:
                     rootdir = get_common_ancestor(
                         invocation_dir, [invocation_dir, ancestor]
@@ -223,7 +234,7 @@ def determine_setup(
                 f"Directory '{rootdir}' not found. Check your '--rootdir' option."
             )
     assert rootdir is not None
-    return rootdir, inipath, inicfg or {}
+    return rootdir, inipath, inicfg or {}, should_warn
 
 
 def is_fs_root(p: Path) -> bool:

src/_pytest/terminal.py

@@ -879,7 +879,12 @@ def pytest_report_header(self, config: Config) -> list[str]:
         result = [f"rootdir: {config.rootpath}"]
 
         if config.inipath:
-            result.append("configfile: " + bestrelpath(config.rootpath, config.inipath))
+            warning = ""
+            if config.should_warn:
+                warning = " (WARNING: ignoring pytest config in pyproject.toml!)"
+            result.append(
+                "configfile: " + bestrelpath(config.rootpath, config.inipath) + warning
+            )
 
         if config.args_source == Config.ArgsSource.TESTPATHS:
             testpaths: list[str] = config.getini("testpaths")

testing/test_config.py

@@ -56,7 +56,7 @@ def test_getcfg_and_config(
             ),
             encoding="utf-8",
         )
-        _, _, cfg = locate_config(Path.cwd(), [sub])
+        _, _, cfg, _ = locate_config(Path.cwd(), [sub])
         assert cfg["name"] == "value"
         config = pytester.parseconfigure(str(sub))
         assert config.inicfg["name"] == "value"
@@ -1635,15 +1635,15 @@ def test_with_ini(self, tmp_path: Path, name: str, contents: str) -> None:
         b = a / "b"
         b.mkdir()
         for args in ([str(tmp_path)], [str(a)], [str(b)]):
-            rootpath, parsed_inipath, _ = determine_setup(
+            rootpath, parsed_inipath, *_ = determine_setup(
                 inifile=None,
                 args=args,
                 rootdir_cmd_arg=None,
                 invocation_dir=Path.cwd(),
             )
             assert rootpath == tmp_path
             assert parsed_inipath == inipath
-        rootpath, parsed_inipath, ini_config = determine_setup(
+        rootpath, parsed_inipath, ini_config, _ = determine_setup(
             inifile=None,
             args=[str(b), str(a)],
             rootdir_cmd_arg=None,
@@ -1660,7 +1660,7 @@ def test_pytestini_overrides_empty_other(self, tmp_path: Path, name: str) -> Non
         a = tmp_path / "a"
         a.mkdir()
         (a / name).touch()
-        rootpath, parsed_inipath, _ = determine_setup(
+        rootpath, parsed_inipath, *_ = determine_setup(
             inifile=None,
             args=[str(a)],
             rootdir_cmd_arg=None,
@@ -1674,7 +1674,7 @@ def test_setuppy_fallback(self, tmp_path: Path) -> None:
         a.mkdir()
         (a / "setup.cfg").touch()
         (tmp_path / "setup.py").touch()
-        rootpath, inipath, inicfg = determine_setup(
+        rootpath, inipath, inicfg, _ = determine_setup(
             inifile=None,
             args=[str(a)],
             rootdir_cmd_arg=None,
@@ -1686,7 +1686,7 @@ def test_setuppy_fallback(self, tmp_path: Path) -> None:
 
     def test_nothing(self, tmp_path: Path, monkeypatch: MonkeyPatch) -> None:
         monkeypatch.chdir(tmp_path)
-        rootpath, inipath, inicfg = determine_setup(
+        rootpath, inipath, inicfg, _ = determine_setup(
             inifile=None,
             args=[str(tmp_path)],
             rootdir_cmd_arg=None,
@@ -1713,7 +1713,7 @@ def test_with_specific_inifile(
         p = tmp_path / name
         p.touch()
         p.write_text(contents, encoding="utf-8")
-        rootpath, inipath, ini_config = determine_setup(
+        rootpath, inipath, ini_config, _ = determine_setup(
             inifile=str(p),
             args=[str(tmp_path)],
             rootdir_cmd_arg=None,
@@ -1761,7 +1761,7 @@ def test_with_arg_outside_cwd_without_inifile(
         a.mkdir()
         b = tmp_path / "b"
         b.mkdir()
-        rootpath, inifile, _ = determine_setup(
+        rootpath, inifile, *_ = determine_setup(
             inifile=None,
             args=[str(a), str(b)],
             rootdir_cmd_arg=None,
@@ -1777,7 +1777,7 @@ def test_with_arg_outside_cwd_with_inifile(self, tmp_path: Path) -> None:
         b.mkdir()
         inipath = a / "pytest.ini"
         inipath.touch()
-        rootpath, parsed_inipath, _ = determine_setup(
+        rootpath, parsed_inipath, *_ = determine_setup(
             inifile=None,
             args=[str(a), str(b)],
             rootdir_cmd_arg=None,
@@ -1791,7 +1791,7 @@ def test_with_non_dir_arg(
         self, dirs: Sequence[str], tmp_path: Path, monkeypatch: MonkeyPatch
     ) -> None:
         monkeypatch.chdir(tmp_path)
-        rootpath, inipath, _ = determine_setup(
+        rootpath, inipath, *_ = determine_setup(
             inifile=None,
             args=dirs,
             rootdir_cmd_arg=None,
@@ -1807,7 +1807,7 @@ def test_with_existing_file_in_subdir(
         a.mkdir()
         (a / "exists").touch()
         monkeypatch.chdir(tmp_path)
-        rootpath, inipath, _ = determine_setup(
+        rootpath, inipath, *_ = determine_setup(
             inifile=None,
             args=["a/exist"],
             rootdir_cmd_arg=None,
@@ -1826,7 +1826,7 @@ def test_with_config_also_in_parent_directory(
         (tmp_path / "myproject" / "tests").mkdir()
         monkeypatch.chdir(tmp_path / "myproject")
 
-        rootpath, inipath, _ = determine_setup(
+        rootpath, inipath, *_ = determine_setup(
             inifile=None,
             args=["tests/"],
             rootdir_cmd_arg=None,

testing/test_terminal.py

@@ -2893,6 +2893,68 @@ def test_format_trimmed() -> None:
     assert _format_trimmed(" ({}) ", msg, len(msg) + 3) == " (unconditional ...) "
 
 
+def test_warning_when_init_trumps_pyproject_toml(
+    pytester: Pytester, monkeypatch: MonkeyPatch
+) -> None:
+    """Regression test for #7814."""
+    tests = pytester.path.joinpath("tests")
+    tests.mkdir()
+    pytester.makepyprojecttoml(
+        f"""
+        [tool.pytest.ini_options]
+        testpaths = ['{tests}']
+    """
+    )
+    pytester.makefile(".ini", pytest="")
+    result = pytester.runpytest()
+    result.stdout.fnmatch_lines(
+        [
+            "configfile: pytest.ini (WARNING: ignoring pytest config in pyproject.toml!)",
+        ]
+    )
+
+
+def test_no_warning_when_init_but_pyproject_toml_has_no_entry(
+    pytester: Pytester, monkeypatch: MonkeyPatch
+) -> None:
+    """Regression test for #7814."""
+    tests = pytester.path.joinpath("tests")
+    tests.mkdir()
+    pytester.makepyprojecttoml(
+        f"""
+        [tool]
+        testpaths = ['{tests}']
+    """
+    )
+    pytester.makefile(".ini", pytest="")
+    result = pytester.runpytest()
+    result.stdout.fnmatch_lines(
+        [
+            "configfile: pytest.ini",
+        ]
+    )
+
+
+def test_no_warning_on_terminal_with_a_single_config_file(
+    pytester: Pytester, monkeypatch: MonkeyPatch
+) -> None:
+    """Regression test for #7814."""
+    tests = pytester.path.joinpath("tests")
+    tests.mkdir()
+    pytester.makepyprojecttoml(
+        f"""
+        [tool.pytest.ini_options]
+        testpaths = ['{tests}']
+    """
+    )
+    result = pytester.runpytest()
+    result.stdout.fnmatch_lines(
+        [
+            "configfile: pyproject.toml",
+        ]
+    )
+
+
 class TestFineGrainedTestCase:
     DEFAULT_FILE_CONTENTS = """
             import pytest