diff options
| -rw-r--r-- | Lib/annotationlib.py | 81 | ||||
| -rw-r--r-- | Lib/test/test_annotationlib.py | 88 |
2 files changed, 143 insertions, 26 deletions
diff --git a/Lib/annotationlib.py b/Lib/annotationlib.py index be3bc27..20c9542 100644 --- a/Lib/annotationlib.py +++ b/Lib/annotationlib.py @@ -664,28 +664,38 @@ def get_annotations( if eval_str and format != Format.VALUE: raise ValueError("eval_str=True is only supported with format=Format.VALUE") - # For VALUE format, we look at __annotations__ directly. - if format != Format.VALUE: - annotate = get_annotate_function(obj) - if annotate is not None: - ann = call_annotate_function(annotate, format, owner=obj) - if not isinstance(ann, dict): - raise ValueError(f"{obj!r}.__annotate__ returned a non-dict") - return dict(ann) - - if isinstance(obj, type): - try: - ann = _BASE_GET_ANNOTATIONS(obj) - except AttributeError: - # For static types, the descriptor raises AttributeError. - return {} - else: - ann = getattr(obj, "__annotations__", None) - if ann is None: - return {} - - if not isinstance(ann, dict): - raise ValueError(f"{obj!r}.__annotations__ is neither a dict nor None") + match format: + case Format.VALUE: + # For VALUE, we only look at __annotations__ + ann = _get_dunder_annotations(obj) + case Format.FORWARDREF: + # For FORWARDREF, we use __annotations__ if it exists + try: + ann = _get_dunder_annotations(obj) + except NameError: + pass + else: + return dict(ann) + + # But if __annotations__ threw a NameError, we try calling __annotate__ + ann = _get_and_call_annotate(obj, format) + if ann is not None: + return ann + + # If that didn't work either, we have a very weird object: evaluating + # __annotations__ threw NameError and there is no __annotate__. In that case, + # we fall back to trying __annotations__ again. + return dict(_get_dunder_annotations(obj)) + case Format.SOURCE: + # For SOURCE, we try to call __annotate__ + ann = _get_and_call_annotate(obj, format) + if ann is not None: + return ann + # But if we didn't get it, we use __annotations__ instead. + ann = _get_dunder_annotations(obj) + return ann + case _: + raise ValueError(f"Unsupported format {format!r}") if not ann: return {} @@ -750,3 +760,30 @@ def get_annotations( for key, value in ann.items() } return return_value + + +def _get_and_call_annotate(obj, format): + annotate = get_annotate_function(obj) + if annotate is not None: + ann = call_annotate_function(annotate, format, owner=obj) + if not isinstance(ann, dict): + raise ValueError(f"{obj!r}.__annotate__ returned a non-dict") + return dict(ann) + return None + + +def _get_dunder_annotations(obj): + if isinstance(obj, type): + try: + ann = _BASE_GET_ANNOTATIONS(obj) + except AttributeError: + # For static types, the descriptor raises AttributeError. + return {} + else: + ann = getattr(obj, "__annotations__", None) + if ann is None: + return {} + + if not isinstance(ann, dict): + raise ValueError(f"{obj!r}.__annotations__ is neither a dict nor None") + return dict(ann) diff --git a/Lib/test/test_annotationlib.py b/Lib/test/test_annotationlib.py index cc051ef..5b052da 100644 --- a/Lib/test/test_annotationlib.py +++ b/Lib/test/test_annotationlib.py @@ -740,17 +740,97 @@ class TestGetAnnotations(unittest.TestCase): self.assertEqual(annotationlib.get_annotations(f), {"x": int}) self.assertEqual( - annotationlib.get_annotations(f, format=annotationlib.Format.FORWARDREF), + annotationlib.get_annotations(f, format=Format.FORWARDREF), {"x": int}, ) f.__annotations__["x"] = str # The modification is reflected in VALUE (the default) self.assertEqual(annotationlib.get_annotations(f), {"x": str}) - # ... but not in FORWARDREF, which uses __annotate__ + # ... and also in FORWARDREF, which tries __annotations__ if available self.assertEqual( - annotationlib.get_annotations(f, format=annotationlib.Format.FORWARDREF), - {"x": int}, + annotationlib.get_annotations(f, format=Format.FORWARDREF), + {"x": str}, + ) + # ... but not in SOURCE which always uses __annotate__ + self.assertEqual( + annotationlib.get_annotations(f, format=Format.SOURCE), + {"x": "int"}, + ) + + def test_non_dict_annotations(self): + class WeirdAnnotations: + @property + def __annotations__(self): + return "not a dict" + + wa = WeirdAnnotations() + for format in Format: + with ( + self.subTest(format=format), + self.assertRaisesRegex( + ValueError, r".*__annotations__ is neither a dict nor None" + ), + ): + annotationlib.get_annotations(wa, format=format) + + def test_annotations_on_custom_object(self): + class HasAnnotations: + @property + def __annotations__(self): + return {"x": int} + + ha = HasAnnotations() + self.assertEqual( + annotationlib.get_annotations(ha, format=Format.VALUE), {"x": int} + ) + self.assertEqual( + annotationlib.get_annotations(ha, format=Format.FORWARDREF), {"x": int} + ) + + # TODO(gh-124412): This should return {'x': 'int'} instead. + self.assertEqual( + annotationlib.get_annotations(ha, format=Format.SOURCE), {"x": int} + ) + + def test_raising_annotations_on_custom_object(self): + class HasRaisingAnnotations: + @property + def __annotations__(self): + return {"x": undefined} + + hra = HasRaisingAnnotations() + + with self.assertRaises(NameError): + annotationlib.get_annotations(hra, format=Format.VALUE) + + with self.assertRaises(NameError): + annotationlib.get_annotations(hra, format=Format.FORWARDREF) + + undefined = float + self.assertEqual( + annotationlib.get_annotations(hra, format=Format.VALUE), {"x": float} + ) + + def test_forwardref_prefers_annotations(self): + class HasBoth: + @property + def __annotations__(self): + return {"x": int} + + @property + def __annotate__(self): + return lambda format: {"x": str} + + hb = HasBoth() + self.assertEqual( + annotationlib.get_annotations(hb, format=Format.VALUE), {"x": int} + ) + self.assertEqual( + annotationlib.get_annotations(hb, format=Format.FORWARDREF), {"x": int} + ) + self.assertEqual( + annotationlib.get_annotations(hb, format=Format.SOURCE), {"x": str} ) def test_pep695_generic_class_with_future_annotations(self): |