Improve Pydantic support for BIC objects

CHANGELOG.rst

@@ -9,8 +9,8 @@ Versions follow `CalVer <http://www.calver.org/>`_ with the scheme ``YY.0M.Micro
 -------------------------
 Fixed
 ~~~~~
-* Loading JSON data into a Pydantic model with an ``IBAN``-field (``Model.model_validate_json()``)
-  was previously broken and has been fixed now.
+* Loading JSON data into a Pydantic model with an ``IBAN`` or ``BIC``-field
+  (``Model.model_validate_json()``) was previously broken and has been fixed now.
 
 Added
 ~~~~~
@@ -19,6 +19,7 @@ Added
 Changed
 ~~~~~~~
 * Updated bank registries.
+* Remove the dependency to ``iso3166`` since its functionallity is already covered by ``pycountry``
 
 
 `2024.04.0`_ - 2024/04/18

schwifty/bic.py

@@ -15,6 +15,9 @@
 
 if TYPE_CHECKING:
     from pydantic import GetCoreSchemaHandler
+    from pydantic import GetJsonSchemaHandler
+    from pydantic import ValidatorFunctionWrapHandler
+    from pydantic.json_schema import JsonSchemaValue
     from pydantic_core import CoreSchema
 
 _bic_iso9362_re = re.compile(r"[A-Z0-9]{4}[A-Z]{2}[A-Z0-9]{2}(?:[A-Z0-9]{3})?")
@@ -285,6 +288,49 @@ def _validate_country_code(self) -> None:
         if self.country is None:
             raise exceptions.InvalidCountryCode(f"Invalid country code '{self.country_code}'")
 
+    @classmethod
+    def __get_pydantic_core_schema__(
+        cls, source: type[Any], handler: GetCoreSchemaHandler
+    ) -> CoreSchema:
+        from pydantic_core import core_schema
+
+        return core_schema.no_info_wrap_validator_function(
+            cls._pydantic_validate,
+            core_schema.union_schema(
+                [
+                    core_schema.is_instance_schema(BIC),
+                    core_schema.no_info_plain_validator_function(BIC),
+                    core_schema.str_schema(
+                        pattern=r"[A-Z0-9]{4}[A-Z]{2}[A-Z0-9]{2}(:?[A-Z0-9]{3})?",
+                        min_length=8,
+                        max_length=11,
+                    ),
+                ]
+            ),
+            serialization=core_schema.to_string_ser_schema(
+                when_used="json-unless-none",
+            ),
+        )
+
+    @classmethod
+    def __get_pydantic_json_schema__(
+        cls, core_schema: CoreSchema, handler: GetJsonSchemaHandler
+    ) -> JsonSchemaValue:
+        json_schema = handler(core_schema)
+        json_schema = handler.resolve_ref_schema(json_schema)
+        json_schema["title"] = "BIC"
+        return json_schema
+
+    @classmethod
+    def _pydantic_validate(cls, value: Any, handler: ValidatorFunctionWrapHandler) -> Any:
+        from pydantic_core import PydanticCustomError
+
+        try:
+            bic = cls(value)
+        except exceptions.SchwiftyException as err:
+            raise PydanticCustomError("bic_format", str(err)) from err
+        return handler(bic)
+
     @property
     def is_valid(self) -> bool:
         """bool: Indicate if this is a valid BIC.
@@ -446,17 +492,6 @@ def branch_code(self) -> str:
         """str: The branch-code part of the BIC (if available)"""
         return self._get_slice(start=8, end=11)
 
-    @classmethod
-    def __get_pydantic_core_schema__(cls, source: Any, handler: GetCoreSchemaHandler) -> CoreSchema:
-        from pydantic_core import core_schema
-
-        return core_schema.union_schema(
-            [
-                core_schema.is_instance_schema(BIC),
-                core_schema.no_info_plain_validator_function(BIC),
-            ]
-        )
-
 
 registry.build_index("bank", "bic", key="bic", accumulate=True)
 registry.build_index(

tests/test_bic.py

@@ -234,6 +234,18 @@ class Model(BaseModel):
 
     model = Model(bic="GENODEM1GLS")  # type: ignore[arg-type]
     assert isinstance(model.bic, BIC)
+    assert model.model_dump() == {"bic": model.bic}
 
-    with pytest.raises(ValidationError):
+    with pytest.raises(ValidationError) as err:
         Model(bic="GENODXM1GLS")  # type: ignore[arg-type]
+    assert len(err.value.errors()) == 1
+    error = err.value.errors()[0]
+    assert error["type"] == "bic_format"
+    assert error["msg"] == "Invalid country code 'DX'"
+    assert error["input"] == "GENODXM1GLS"
+
+    dumped = model.model_dump_json()
+    assert dumped == '{"bic":"GENODEM1GLS"}'
+
+    loaded = Model.model_validate_json(dumped)
+    assert loaded == model