Merge pull request #7 from AdCombo/6-fix-sqlalchemy-datalayer-create-object

fix: SqlalchemyDataLayer fails on models with __init__ statement

Author: Znbiz

flask_combo_jsonapi/resource.py

@@ -17,7 +17,7 @@
 from flask_combo_jsonapi.schema import compute_schema, get_relationships, get_model_field
 from flask_combo_jsonapi.data_layers.base import BaseDataLayer
 from flask_combo_jsonapi.data_layers.alchemy import SqlalchemyDataLayer
-from flask_combo_jsonapi.utils import JSONEncoder
+from flask_combo_jsonapi.utils import JSONEncoder, validate_model_init_params
 
 
 class ResourceMeta(MethodViewType):
@@ -39,6 +39,14 @@ def __new__(cls, name, bases, d):
             data_layer_kwargs = d["data_layer"]
             rv._data_layer = data_layer_cls(data_layer_kwargs)
 
+            if "schema" in d and "model" in data_layer_kwargs:
+                model = data_layer_kwargs["model"]
+                schema_fields = [get_model_field(d["schema"], key) for key in d["schema"]._declared_fields.keys()]
+                invalid_params = validate_model_init_params(model=model, params_names=schema_fields)
+                if invalid_params:
+                    raise Exception(f"Construction of {name} failed. Schema '{d['schema'].__name__}' has "
+                                    f"fields={invalid_params} are not declare in {model.__name__} init parameters")
+
         rv.decorators = (check_headers,)
         if "decorators" in d:
             rv.decorators += d["decorators"]

flask_combo_jsonapi/utils.py

@@ -1,3 +1,5 @@
+import inspect
+
 import simplejson as json
 from uuid import UUID
 from datetime import datetime
@@ -17,3 +19,30 @@ def default(self, obj):
         elif isinstance(obj, UUID):
             return str(obj)
         return json.JSONEncoder.default(self, obj)
+
+
+def get_model_init_params_names(model):
+    """Retrieve all params of model init method
+
+    :param DeclarativeMeta model: an object from sqlalchemy
+    :return tuple: list of init method fields names and boolean flag that init method has kwargs
+    """
+    argnames, _, varkw = inspect.getfullargspec(model.__init__)[:3]
+    if argnames:
+        argnames.remove('self')
+    return argnames, bool(varkw)
+
+
+def validate_model_init_params(model, params_names):
+    """Retrieve invalid params of model init method if it exists
+    :param DeclarativeMeta model: an object from sqlalchemy
+    :param list params_names: parameters names to check
+    :return list: list of invalid fields or None
+    """
+    init_args, has_kwargs = get_model_init_params_names(model)
+    if has_kwargs:
+        return
+
+    invalid_params = [name for name in params_names if name not in init_args]
+    if invalid_params:
+        return invalid_params

tests/test_resource.py

@@ -0,0 +1,61 @@
+from unittest.mock import Mock
+
+import pytest
+from marshmallow_jsonapi import fields, Schema
+from sqlalchemy import Column, Integer, String
+from sqlalchemy.ext.declarative import declarative_base
+
+from flask_combo_jsonapi import ResourceList
+
+
+@pytest.fixture(scope='module')
+def base():
+    yield declarative_base()
+
+
+@pytest.fixture(scope='module')
+def model(base):
+    class SampleModel(base):
+        __tablename__ = 'model_sample'
+
+        id = Column(Integer, primary_key=True, index=True)
+        key1 = Column(String)
+        key2 = Column(String)
+
+        def __init__(self, key1):
+            pass
+
+    yield SampleModel
+
+
+@pytest.fixture(scope='module')
+def schema_for_model(model):
+    class SampleSchema(Schema):
+        class Meta:
+            model = model
+
+        id = fields.Integer()
+        key1 = fields.String()
+        key2 = fields.String()
+
+    yield SampleSchema
+
+
+def test_resource_meta_init(model, schema_for_model):
+    expected_fields = ['id', 'key2']
+    raised_ex = None
+    try:
+        class SampleResourceList(ResourceList):
+            schema = schema_for_model
+            methods = ['GET', 'POST']
+            data_layer = {
+                'session': Mock(),
+                'model': model,
+            }
+    except Exception as ex:
+        raised_ex = ex
+
+    assert raised_ex
+    message = f"Construction of SampleResourceList failed. Schema '{schema_for_model.__name__}' " \
+              f"has fields={expected_fields}"
+    assert message in str(raised_ex)

tests/test_utils.py

@@ -0,0 +1,73 @@
+import pytest
+from sqlalchemy import Column, Integer, String
+from sqlalchemy.ext.declarative import declarative_base
+
+from flask_combo_jsonapi.utils import get_model_init_params_names, validate_model_init_params
+
+
+@pytest.fixture(scope='module')
+def base():
+    yield declarative_base()
+
+
+@pytest.fixture(scope='module')
+def model_without_init(base):
+    class ModelWithoutInit(base):
+        __tablename__ = 'model_without_init'
+
+        id = Column(Integer, primary_key=True, index=True)
+        key1 = Column(String)
+        key2 = Column(String)
+
+    yield ModelWithoutInit
+
+
+@pytest.fixture(scope='module')
+def model_with_kwargs_in_init(base):
+    class ModelWithKwargsInit(base):
+        __tablename__ = 'model_with_kwargs_init'
+
+        id = Column(Integer, primary_key=True, index=True)
+        key1 = Column(String)
+        key2 = Column(String)
+
+        def __init__(self, key1=0, **kwargs):
+            pass
+
+    yield ModelWithKwargsInit
+
+
+@pytest.fixture(scope='module')
+def model_with_positional_args_init(base):
+    class ModelWithPositionalArgsInit(base):
+        __tablename__ = 'model_with_positional_args_init'
+
+        id = Column(Integer, primary_key=True, index=True)
+        key1 = Column(String)
+        key2 = Column(String)
+
+        def __init__(self, key1, key2=0):
+            pass
+
+    yield ModelWithPositionalArgsInit
+
+
+def test_get_model_init_params_names(model_without_init, model_with_kwargs_in_init,
+                                     model_with_positional_args_init):
+    args, has_kwargs = get_model_init_params_names(model_without_init)
+    assert ([], True) == (args, has_kwargs)
+
+    args, has_kwargs = get_model_init_params_names(model_with_kwargs_in_init)
+    assert (['key1'], True) == (args, has_kwargs)
+
+    args, has_kwargs = get_model_init_params_names(model_with_positional_args_init)
+    assert (['key1', 'key2'], False) == (args, has_kwargs)
+
+
+def test_validate_model_init_params(model_with_kwargs_in_init, model_with_positional_args_init):
+    schema_attrs = ['id', 'key1', 'key2']
+    invalid_params = validate_model_init_params(model_with_kwargs_in_init, schema_attrs)
+    assert invalid_params is None
+
+    invalid_params = validate_model_init_params(model_with_positional_args_init, schema_attrs)
+    assert invalid_params == ['id']