Test attrs helpers

pyproject.toml

@@ -120,7 +120,8 @@ docstring-code-format = true
 "test*.py" = [
     "D",  # Documentation not needed in tests
     "S101",  # S101 Use of `assert` detected
-    "PLR2004" # Magic value used in comparison
+    "PLR2004",  # Magic value used in comparison
+    "TRY003",  # Test code, it's fine
 ]
 "docs/source/notebooks/*" = [
     "D100",  # Missing docstring at the top of file

src/pydoit_nb/attrs_helpers.py

@@ -17,6 +17,40 @@
     T = TypeVar("T")
 
 
+class AttributeInitialisationError(ValueError):
+    """
+    Raised when there is an issue while initialising an :obj:`attr.Attribute`
+    """
+
+    def __init__(
+        self,
+        instance: Any,
+        attribute: attr.Attribute[Any],
+        value: T,
+    ) -> None:
+        """
+        Initialise the error
+
+        Parameters
+        ----------
+        instance
+            Instance being initialised
+
+        attribute
+            Attribute being set
+
+        value
+            Value being used to set the attribute
+        """
+        error_msg = (
+            "Error raised while initialising attribute "
+            f"``{attribute.name}`` of ``{type(instance)}``. "
+            f"Value provided: {value}"
+        )
+
+        super().__init__(error_msg)
+
+
 def add_attrs_context(
     original: Callable[[Any, attr.Attribute[Any], T], None],
 ) -> Callable[[Any, attr.Attribute[Any], T], None]:
@@ -50,14 +84,7 @@ def with_attrs_context(
         try:
             original(instance, attribute, value)
         except Exception as exc:
-            if hasattr(exc, "add_note"):
-                exc.add_note(
-                    "\nError raised while initialising attribute "
-                    f"``{attribute.name}`` of ``{type(instance)}``. "
-                    f"\nValue provided: {value}"
-                )
-
-            raise
+            raise AttributeInitialisationError(instance=instance, attribute=attribute, value=value) from exc
 
     return with_attrs_context
 

tests/unit/test_attrs_helpers.py

@@ -0,0 +1,35 @@
+"""
+Test attrs_helpers module
+"""
+import re
+from unittest.mock import Mock
+
+import pytest
+
+from pydoit_nb.attrs_helpers import AttributeInitialisationError, make_attrs_validator_compatible_single_input
+
+
+def test_make_attrs_validator_compatible_single_input():
+    def func(inp: str) -> None:
+        if inp != "hi":
+            raise ValueError(f"inp must be hi, received: {inp}")
+
+    wrapped = make_attrs_validator_compatible_single_input(func)
+
+    instance = Mock()
+    attribute = Mock()
+    attribute.name = "attribute_name"
+    # No error
+    wrapped(instance, attribute, "hi")
+
+    # Error
+    error_msg = re.escape(
+        "Error raised while initialising attribute "
+        f"``attribute_name`` of ``{type(instance)}``. "
+        "Value provided: bye"
+    )
+    with pytest.raises(AttributeInitialisationError, match=error_msg) as exc:
+        wrapped(instance, attribute, "bye")
+
+    assert isinstance(exc.value.__cause__, ValueError)
+    assert str(exc.value.__cause__) == "inp must be hi, received: bye"