feat: Warn when an object coming from a sibling, parent or external m…

…odule instead of the current module or a submodule is exported

Implemented as a DEBUG log for now, waiting for a logging configuration system.

Issue-249: #249
Related-to-PR-251: #251

src/_griffe/loader.py

@@ -13,7 +13,13 @@
 from _griffe.agents.visitor import visit
 from _griffe.collections import LinesCollection, ModulesCollection
 from _griffe.enumerations import Kind
-from _griffe.exceptions import AliasResolutionError, CyclicAliasError, LoadingError, UnimportableModuleError
+from _griffe.exceptions import (
+    AliasResolutionError,
+    CyclicAliasError,
+    LoadingError,
+    NameResolutionError,
+    UnimportableModuleError,
+)
 from _griffe.expressions import ExprName
 from _griffe.extensions.base import Extensions, load_extensions
 from _griffe.finder import ModuleFinder, NamespacePackage, Package
@@ -292,6 +298,7 @@ def expand_exports(self, module: Module, seen: set | None = None) -> None:
         seen.add(module.path)
         if module.exports is None:
             return
+
         expanded = set()
         for export in module.exports:
             # It's a name: we resolve it, get the module it comes from,
@@ -311,9 +318,21 @@ def expand_exports(self, module: Module, seen: set | None = None) -> None:
                         _logger.warning(f"Unsupported item in {module.path}.__all__: {export} (use strings only)")
             # It's a string, simply add it to the current exports.
             else:
+                with suppress(NameResolutionError):
+                    if not module.resolve(export).startswith(module.path):
+                        # NOTE: This won't work for built-in attributes during inspection,
+                        # since their canonical module cannot be determined.
+                        _logger.debug(
+                            f"Name `{export}` exported by module `{module.path}` doesn't come from this module or from a submodule.",
+                        )
                 expanded.add(export)
         module.exports = expanded
 
+        # Make sure to expand exports in all modules.
+        for submodule in module.modules.values():
+            if not submodule.is_alias and submodule.path not in seen:
+                self.expand_exports(submodule, seen)
+
     def expand_wildcards(
         self,
         obj: Object,

tests/test_loader.py

@@ -8,7 +8,7 @@
 
 import pytest
 
-from griffe import ExprName, GriffeLoader, temporary_pyfile, temporary_pypackage, temporary_visited_package
+from griffe import ExprName, GriffeLoader, load, temporary_pyfile, temporary_pypackage, temporary_visited_package
 from tests.helpers import clear_sys_modules
 
 if TYPE_CHECKING:
@@ -101,7 +101,7 @@ def test_load_data_from_stubs() -> None:
         code = '''
             from typing import List, Literal, Optional, Protocol, Set, Tuple, Union
 
-            __all__ = 'RustNotify', 'WatchfilesRustInternalError'
+            __all__ = ['RustNotify']
 
             class AbstractEvent(Protocol):
                 def is_set(self) -> bool: ...
@@ -484,3 +484,24 @@ def test_not_calling_package_loaded_hook_on_something_else_than_package() -> Non
         alias: Alias = loader.load("pkg.L")
         assert alias.is_alias
         assert not alias.resolved
+
+
+@pytest.mark.parametrize("force_inspection", [True, False])
+def test_warning_on_objects_from_non_submodules_being_exported(
+    caplog: pytest.LogCaptureFixture,
+    force_inspection: bool,
+) -> None:
+    """Warn when objects from non-submodules are exported."""
+    with temporary_pypackage(
+        "pkg",
+        {
+            "__init__.py": "from typing import List\nfrom pkg import moda, modb\n__all__ = ['List']",
+            "moda.py": "class Thing: ...",
+            "modb.py": "from pkg.moda import Thing\n\n__all__ = ['Thing']",
+        },
+    ) as pkg:
+        with caplog.at_level(logging.DEBUG, logger="griffe"):
+            load("pkg", search_paths=[pkg.tmpdir], force_inspection=force_inspection, resolve_aliases=True)
+        messages = [record.message for record in caplog.records]
+        assert any("Name `List` exported by module" in msg for msg in messages)
+        assert any("Name `Thing` exported by module" in msg for msg in messages)