Hetero tuple extended validation

Author: Tinche

src/cattr/converters.py

@@ -585,7 +585,7 @@ def _structure_tuple(self, obj, tup: Type[T]):
                     try:
                         res.append(conv(e, tup_type))
                     except Exception as exc:
-                        exc.__note__ = f"Structuring tuple @ index {ix}"
+                        exc.__note__ = f"Structuring {tup} @ index {ix}"
                         errors.append(exc)
                 if errors:
                     raise IterableValidationError(f"While structuring {tup.__name__}", errors, tup)
@@ -594,10 +594,24 @@ def _structure_tuple(self, obj, tup: Type[T]):
                 return tuple(conv(e, tup_type) for e in obj)
         else:
             # We're dealing with a heterogenous tuple.
-            return tuple(
-                self._structure_func.dispatch(t)(e, t)
-                for t, e in zip(tup_params, obj)
-            )
+            if self.extended_validation:
+                errors = []
+                res = []
+                for ix, (t, e) in enumerate(zip(tup_params, obj)):
+                    try:
+                        conv = self._structure_func.dispatch(t)
+                        res.append(conv(e, t))
+                    except Exception as exc:
+                        exc.__note__ = f"Structuring {tup} @ index {ix}"
+                        errors.append(exc)
+                if errors:
+                    raise IterableValidationError(f"While structuring {tup.__name__}", errors, tup)
+                return tuple(res)
+            else:
+                return tuple(
+                    (e, t)
+                    for t, e in zip(tup_params, obj)
+                )
 
     @staticmethod
     def _get_dis_func(union):

src/cattrs/gen.py

@@ -340,7 +340,7 @@ def make_dict_structure_fn(
             lines.append(f"{i}except Exception as e:")
             i = f"{i}  "
             lines.append(
-                f"{i}e.__note__ = 'Structuring class @ attribute {an}'"
+                f"{i}e.__note__ = 'Structuring class {cl_name} @ attribute {an}'"
             )
             lines.append(f"{i}errors.append(e)")
         post_lines.append(f"  if errors: raise __c_cve('While structuring {cl.__name__}', errors, __cl)")

tests/test_validation.py

@@ -25,10 +25,10 @@ class Test:
     assert repr(exc.value.exceptions[0]) == repr(
         ValueError("invalid literal for int() with base 10: 'a'")
     )
-    assert exc.value.exceptions[0].__note__ == "Structuring class @ attribute a"
+    assert exc.value.exceptions[0].__note__ == "Structuring class Test @ attribute a"
 
     assert repr(exc.value.exceptions[1]) == repr(KeyError("c"))
-    assert exc.value.exceptions[1].__note__ == "Structuring class @ attribute c"
+    assert exc.value.exceptions[1].__note__ == "Structuring class Test @ attribute c"
 
 
 def test_list_validation():
@@ -103,4 +103,17 @@ def test_homo_tuple_validation():
     assert repr(exc.value.exceptions[0]) == repr(
         ValueError("invalid literal for int() with base 10: 'a'")
     )
-    assert exc.value.exceptions[0].__note__ == "Structuring tuple @ index 2"
+    assert exc.value.exceptions[0].__note__ == "Structuring typing.Tuple[int, ...] @ index 2"
+
+
+def test_hetero_tuple_validation():
+    """Proper validation errors are raised structuring heterogenous tuples."""
+    c = GenConverter(extended_validation=True)
+
+    with pytest.raises(IterableValidationError) as exc:
+        c.structure(["1", 2, "a"], Tuple[int, int, int])
+
+    assert repr(exc.value.exceptions[0]) == repr(
+        ValueError("invalid literal for int() with base 10: 'a'")
+    )
+    assert exc.value.exceptions[0].__note__ == "Structuring typing.Tuple[int, int, int] @ index 2"