Bump version

README.md

@@ -1,6 +1,6 @@
 # megasniff
 
-### Автоматическая валидация данных по схеме и сборка объекта в одном флаконе
+### Автоматическая валидация данных по схеме, сборка и разборка объекта в одном флаконе
 
 #### Как применять:
 
@@ -18,7 +18,8 @@ class SomeSchema1:
     c: SomeSchema2 | str | None
 
 
-class SomeSchema2(typing.TypedDict):
+@dataclasses.dataclass
+class SomeSchema2:
     field1: dict
     field2: float
     field3: typing.Optional[SomeSchema1]
@@ -28,12 +29,16 @@ class SomeSchema2(typing.TypedDict):
 import megasniff
 
 infl = megasniff.SchemaInflatorGenerator()
-fn = infl.schema_to_inflator(SomeSchema1)
+defl = megasniff.SchemaDeflatorGenerator()
+fn_in = infl.schema_to_inflator(SomeSchema1)
+fn_out = defl.schema_to_deflator(SomeSchema1)
 
 # 3. Проверяем что всё работает
 
-fn({'a': 1, 'b': 2, 'c': {'field1': {}, 'field2': '1.1', 'field3': None}})
+data = fn_in({'a': 1, 'b': 2, 'c': {'field1': {}, 'field2': '1.1', 'field3': None}})
 # SomeSchema1(a=1, b=2.0, c={'field1': {}, 'field2': 1.1, 'field3': None})
+fn_out(data)
+# {'a': 1, 'b': 2.0, 'c': {'field1': {}, 'field2': 1.1, 'field3': None}}
 
 ```
 
@@ -47,7 +52,11 @@ fn({'a': 1, 'b': 2, 'c': {'field1': {}, 'field2': '1.1', 'field3': None}})
 - не проверяет типы generic-словарей, кортежей (реализация ожидается)
 - пользовательские проверки типов должны быть реализованы через наследование и проверки в конструкторе
 - опциональный `strict-mode`: выключение приведения базовых типов
-- может генерировать кортежи верхнеуровневых объектов при наличии описания схемы (полезно при развертывании аргументов)
+- для inflation может генерировать кортежи верхнеуровневых объектов при наличии описания схемы (полезно при
+  развертывании аргументов)
+- `TypedDict` поддерживается только для inflation из-за сложностей выбора варианта при сборке `Union`-полей
+- для deflation поддерживается включение режима `explicit_casts`, приводящего типы к тем, которые указаны в
+  аннотациях (не распространяется на `Union`-типы, т.к. невозможно определить какой из них должен быть выбран)
 
 ----
 
@@ -88,6 +97,9 @@ class A:
 ```
 >>> {"a": [1, 1.1, "321"]}
 <<< A(a=[1, 1, 321])
+>>> A(a=[1, 1.1, "321"])
+<<< {"a": [1, 1.1, "321"]}  # explicit_casts=False
+<<< {"a": [1, 1, 321]}  # explicit_casts=True
 ```
 
 #### Strict-mode on:
@@ -101,11 +113,15 @@ class A:
 ```
 >>> {"a": [1, 1.1, "321"]}
 <<< FieldValidationException, т.к. 1.1 не является int
+>>> A(a=[1, 1.1, "321"])
+<<< FieldValidationException, т.к. 1.1 не является int
 ```
 
 ### Tuple unwrap
+
 ```
 fn = infl.schema_to_inflator(
         (('a', int), TupleSchemaItem(Optional[list[int]], key_name='b', has_default=True, default=None)))
 ```
+
 Создаёт `fn: (dict[str,Any]) -> tuple[int, Optional[list[int]]]: ...` (сигнатура остаётся `(dict[str,Any])->tuple`)

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "megasniff"
-version = "0.2.3.post2"
+version = "0.2.4"
 description = "Library for in-time codegened type validation"
 authors = [
     { name = "nikto_b", email = "niktob560@yandex.ru" }

src/megasniff/__init__.py

@@ -1 +1,2 @@
 from .inflator import SchemaInflatorGenerator
+from .deflator import SchemaDeflatorGenerator

src/megasniff/__main__.py

@@ -1,10 +1,13 @@
 from __future__ import annotations
 
+import json
 from dataclasses import dataclass
+from types import NoneType
 from typing import Optional
 from typing import TypedDict
 
 import megasniff.exceptions
+from megasniff.deflator import SchemaDeflatorGenerator, JsonObject
 from . import SchemaInflatorGenerator
 
 
@@ -16,7 +19,8 @@ class ASchema:
     c: float = 1.1
 
 
-class BSchema(TypedDict):
+@dataclass
+class BSchema:
     a: int
     b: str
     c: float
@@ -55,5 +59,40 @@ def main():
         print(e)
 
 
+@dataclass
+class DSchema:
+    a: dict
+    b: dict[str, int | float | dict]
+    c: str | float | ASchema
+    d: ESchema
+
+
+@dataclass
+class ESchema:
+    a: list[list[list[str]]]
+    b: str | int
+
+
+@dataclass
+class ZSchema:
+    z: ZSchema | None
+    d: ZSchema | int
+
+
+def main_deflator():
+    deflator = SchemaDeflatorGenerator(store_sources=True, explicit_casts=True, strict_mode=True)
+    fn = deflator.schema_to_deflator(DSchema)
+    print(getattr(fn, '__megasniff_sources__', '## No data'))
+    # ret = fn(ZSchema(ZSchema(ZSchema(None, 42), 42), ZSchema(None, 42)))
+    ret = fn(DSchema({'a': 34}, {}, ASchema(1, 'a', None), ESchema([[['a'], ['b']]], ['b'])))
+    # assert ret['a'] == 1
+    # assert ret['b'] == 1.1
+    # assert ret['c'] == 'a'
+    # assert ret['d']['a'][0][0][0] == 'a'
+    # assert ret['d']['b'] == 'b'
+    print(json.dumps(ret, indent=4))
+    pass
+
+
 if __name__ == '__main__':
-    main()
+    main_deflator()

src/megasniff/deflator.py

@@ -0,0 +1,307 @@
+# Copyright (C) 2025 Shevchenko A
+# SPDX-License-Identifier: LGPL-3.0-or-later
+from __future__ import annotations
+
+import importlib.resources
+import typing
+from collections.abc import Callable
+from dataclasses import dataclass
+from types import NoneType, UnionType
+from typing import get_args, Union, Annotated, Sequence, TypeAliasType, \
+    OrderedDict, TypeAlias
+
+import jinja2
+
+from .utils import *
+
+JsonObject: TypeAlias = Union[None, bool, int, float, str, list['JsonObject'], dict[str, 'JsonObject']]
+
+
+class Unwrapping:
+    kind: str
+
+
+class OtherUnwrapping(Unwrapping):
+    tp: str
+
+    def __init__(self, tp: str = ''):
+        self.kind = 'other'
+        self.tp = tp
+
+
+@dataclass()
+class ObjectFieldUnwrapping:
+    key: str
+    object_key: str
+    unwrapping: Unwrapping
+
+
+class ObjectUnwrapping(Unwrapping):
+    fields: list[ObjectFieldUnwrapping]
+
+    def __init__(self, fields: list[ObjectFieldUnwrapping]):
+        self.kind = 'object'
+        self.fields = fields
+
+
+class ListUnwrapping(Unwrapping):
+    item_unwrap: Unwrapping
+
+    def __init__(self, item_unwrap: Unwrapping):
+        self.kind = 'list'
+        self.item_unwrap = item_unwrap
+
+
+class DictUnwrapping(Unwrapping):
+    key_unwrap: Unwrapping
+    value_unwrap: Unwrapping
+
+    def __init__(self, key_unwrap: Unwrapping, value_unwrap: Unwrapping):
+        self.kind = 'dict'
+        self.key_unwrap = key_unwrap
+        self.value_unwrap = value_unwrap
+
+
+class FuncUnwrapping(Unwrapping):
+    fn: str
+
+    def __init__(self, fn: str):
+        self.kind = 'fn'
+        self.fn = fn
+
+
+@dataclass
+class UnionKindUnwrapping:
+    kind: str
+    unwrapping: Unwrapping
+
+
+class UnionUnwrapping(Unwrapping):
+    union_kinds: list[UnionKindUnwrapping]
+
+    def __init__(self, union_kinds: list[UnionKindUnwrapping]):
+        self.kind = 'union'
+        self.union_kinds = union_kinds
+
+
+def _flatten_type(t: type | TypeAliasType) -> tuple[type, Optional[str]]:
+    if isinstance(t, TypeAliasType):
+        return _flatten_type(t.__value__)
+
+    origin = get_origin(t)
+
+    if origin is Annotated:
+        args = get_args(t)
+        return _flatten_type(args[0])[0], args[1]
+
+    return t, None
+
+
+def _schema_to_deflator_func(t: type | TypeAliasType) -> str:
+    t, _ = _flatten_type(t)
+    return 'deflate_' + typename(t).replace('.', '_')
+
+
+def _fallback_unwrapper(obj: Any) -> JsonObject:
+    if isinstance(obj, (int, float, str, bool)):
+        return obj
+    elif isinstance(obj, list):
+        return list(map(_fallback_unwrapper, obj))
+    elif isinstance(obj, dict):
+        return dict(map(lambda x: (_fallback_unwrapper(x[0]), _fallback_unwrapper(x[1])), obj.items()))
+    elif hasattr(obj, '__dict__'):
+        ret = {}
+        for k, v in obj.__dict__:
+            if isinstance(k, str) and k.startswith('_'):
+                continue
+            k = _fallback_unwrapper(k)
+            v = _fallback_unwrapper(v)
+            ret[k] = v
+        return ret
+    return None
+
+
+class SchemaDeflatorGenerator:
+    templateLoader: jinja2.BaseLoader
+    templateEnv: jinja2.Environment
+
+    object_template: jinja2.Template
+    _store_sources: bool
+    _strict_mode: bool
+    _explicit_casts: bool
+
+    def __init__(self,
+                 loader: Optional[jinja2.BaseLoader] = None,
+                 strict_mode: bool = False,
+                 explicit_casts: bool = False,
+                 store_sources: bool = False,
+                 *,
+                 object_template_filename: str = 'deflator.jinja2',
+                 ):
+
+        self._strict_mode = strict_mode
+        self._store_sources = store_sources
+        self._explicit_casts = explicit_casts
+
+        if loader is None:
+            template_path = importlib.resources.files('megasniff.templates')
+            loader = jinja2.FileSystemLoader(str(template_path))
+
+        self.templateLoader = loader
+        self.templateEnv = jinja2.Environment(loader=self.templateLoader)
+        self.object_template = self.templateEnv.get_template(object_template_filename)
+
+    def schema_to_deflator(self,
+                           schema: type,
+                           strict_mode_override: Optional[bool] = None,
+                           explicit_casts_override: Optional[bool] = None,
+                           ) -> Callable[[Any], dict[str, Any]]:
+        txt, namespace = self._schema_to_deflator(schema,
+                                                  strict_mode_override=strict_mode_override,
+                                                  explicit_casts_override=explicit_casts_override,
+                                                  )
+        imports = ('from typing import Any\n'
+                   'from megasniff.exceptions import MissingFieldException, FieldValidationException\n')
+        txt = imports + '\n' + txt
+        exec(txt, namespace)
+        fn = namespace[_schema_to_deflator_func(schema)]
+        if self._store_sources:
+            setattr(fn, '__megasniff_sources__', txt)
+        return fn
+
+    def schema_to_unwrapper(self, schema: type | TypeAliasType, *, _visited_types: Optional[list[type]] = None):
+        if _visited_types is None:
+            _visited_types = []
+        else:
+            _visited_types = _visited_types.copy()
+
+        schema, field_rename = _flatten_type(schema)
+
+        if schema in _visited_types:
+            return FuncUnwrapping(_schema_to_deflator_func(schema)), field_rename, set(), {schema}
+        _visited_types.append(schema)
+        ongoing_types = set()
+        recurcive_types = set()
+
+        origin = get_origin(schema)
+
+        ret_unw = None
+
+        if origin is not None:
+            if origin is list:
+                args = get_args(schema)
+                item_unw, arg_rename, ongoings, item_rec = self.schema_to_unwrapper(args[0],
+                                                                                    _visited_types=_visited_types)
+                ret_unw = ListUnwrapping(item_unw)
+                recurcive_types |= item_rec
+                ongoing_types |= ongoings
+            elif origin is dict:
+                args = get_args(schema)
+                if len(args) != 2:
+                    ret_unw = OtherUnwrapping()
+                else:
+                    k, v = args
+                    k_unw, _, k_ongoings, k_rec = self.schema_to_unwrapper(k, _visited_types=_visited_types)
+                    v_unw, _, v_ongoings, v_rec = self.schema_to_unwrapper(k, _visited_types=_visited_types)
+                    ongoing_types |= k_ongoings | v_ongoings
+                    recurcive_types |= k_rec | v_rec
+                    ret_unw = DictUnwrapping(k_unw, v_unw)
+            elif origin is UnionType or origin is Union:
+                args = get_args(schema)
+                union_unwraps = []
+                for targ in args:
+                    arg_unw, arg_rename, ongoings, arg_rec = self.schema_to_unwrapper(targ,
+                                                                                      _visited_types=_visited_types)
+                    union_unwraps.append(UnionKindUnwrapping(typename(targ), arg_unw))
+                    ongoing_types |= ongoings
+                    recurcive_types |= arg_rec
+                ret_unw = UnionUnwrapping(union_unwraps)
+            else:
+                raise NotImplementedError
+        else:
+            if schema is int:
+                ret_unw = OtherUnwrapping('int')
+            elif schema is float:
+                ret_unw = OtherUnwrapping('float')
+            elif schema is bool:
+                ret_unw = OtherUnwrapping('bool')
+            elif schema is str:
+                ret_unw = OtherUnwrapping('str')
+            elif schema is None or schema is NoneType:
+                ret_unw = OtherUnwrapping()
+            elif schema is dict:
+                ret_unw = OtherUnwrapping()
+            elif schema is list:
+                ret_unw = OtherUnwrapping()
+            elif is_class_definition(schema):
+                hints = typing.get_type_hints(schema)
+                fields = []
+                for k, f in hints.items():
+                    f_unw, f_rename, ongoings, f_rec = self.schema_to_unwrapper(f, _visited_types=_visited_types)
+                    fields.append(ObjectFieldUnwrapping(f_rename or k, k, f_unw))
+                    ongoing_types |= ongoings
+                    recurcive_types |= f_rec
+
+                ret_unw = ObjectUnwrapping(fields)
+            else:
+                raise NotImplementedError()
+
+        return ret_unw, field_rename, set(_visited_types) | ongoing_types, recurcive_types
+
+    def _schema_to_deflator(self,
+                            schema: type | Sequence[TupleSchemaItem | tuple[str, type]] | OrderedDict[str, type],
+                            strict_mode_override: Optional[bool] = None,
+                            explicit_casts_override: Optional[bool] = None,
+                            into_type_override: Optional[type | TypeAliasType] = None,
+                            *,
+                            _funcname='deflate',
+                            _namespace=None,
+                            ) -> tuple[str, dict]:
+        if strict_mode_override is not None:
+            strict_mode = strict_mode_override
+        else:
+            strict_mode = self._strict_mode
+        if explicit_casts_override is not None:
+            explicit_casts = explicit_casts_override
+        else:
+            explicit_casts = self._explicit_casts
+
+        template = self.object_template
+
+        types_for_namespace = set()
+        recursive_types = {schema}
+
+        namespace = {
+            'JsonObject': JsonObject,
+            'fallback_unwrapper': _fallback_unwrapper,
+        }
+
+        convertor_functext = ''
+
+        added_types = set()
+
+        while len(recursive_types ^ (recursive_types & added_types)) > 0:
+            rec_t = list(recursive_types ^ (recursive_types & added_types))[0]
+            rec_unw, _, rec_t_namespace, rec_rec_t = self.schema_to_unwrapper(rec_t)
+            recursive_types |= rec_rec_t
+            types_for_namespace |= rec_t_namespace
+
+            rec_functext = template.render(
+                funcname=_schema_to_deflator_func(rec_t),
+                from_type=typename(rec_t),
+                into_type=None,
+                root_unwrap=rec_unw,
+                hashname=hashname,
+                strict_check=strict_mode,
+                explicit_cast=explicit_casts,
+            )
+
+            convertor_functext += '\n\n\n' + rec_functext
+            added_types.add(rec_t)
+
+        for t in types_for_namespace:
+            namespace[typename(t)] = t
+
+        convertor_functext = '\n'.join(list(filter(lambda x: len(x.strip()), convertor_functext.split('\n'))))
+
+        return convertor_functext, namespace

src/megasniff/templates/deflator.jinja2

@@ -0,0 +1,110 @@
+{% macro render_unwrap_object(unwrapping, from_container, into_container) -%}
+{%- set out -%}
+{{ into_container }} = {}
+{% for kv in unwrapping.fields %}
+{{ render_unwrap(kv.unwrapping, from_container + '.' + kv.object_key, into_container + "['" + kv.key + "']") }}
+{% endfor %}
+{%- endset %}
+{{out}}
+{%- endmacro %}
+
+{% macro render_unwrap_dict(unwrapping, from_container, into_container) -%}
+{%- set out -%}
+{{ into_container }} = {}
+{% if strict_check %}
+if not isinstance({{from_container}}, dict):
+    raise FieldValidationException('{{from_container.replace("'", "\\'")}}', 'dict', str(type({{from_container}})))
+{% endif %}
+{% if explicit_cast %}
+{% set from_container = 'dict(' + from_container + ')' %}
+{% endif %}
+for k_{{hashname(unwrapping)}}, v_{{hashname(unwrapping)}} in {{from_container}}.items():
+{{ render_unwrap(unwrapping.key_unwrap, 'k_' + hashname(unwrapping), 'k_' + hashname(unwrapping)) | indent(4) }}
+{{ render_unwrap(unwrapping.value_unwrap, into_container + '[v_' + hashname(unwrapping) + ']', 'v_' + hashname(unwrapping)) | indent(4) }}
+{%- endset %}
+{{out}}
+{%- endmacro %}
+
+{% macro render_unwrap_list(unwrapping, from_container, into_container) -%}
+{%- set out -%}
+{{into_container}} = []
+{% if strict_check %}
+if not isinstance({{from_container}}, list):
+    raise FieldValidationException('{{from_container.replace("'", "\\'")}}', 'list', str(type({{from_container}})))
+{% endif %}
+{% if explicit_cast %}
+{% set from_container = 'list(' + from_container + ')' %}
+{% endif %}
+for {{hashname(unwrapping)}} in {{from_container}}:
+{{ render_unwrap(unwrapping.item_unwrap, hashname(unwrapping), hashname(unwrapping)+'_tmp_container') | indent(4) }}
+    {{into_container}}.append({{hashname(unwrapping)}}_tmp_container)
+{%- endset %}
+{{out}}
+{%- endmacro %}
+
+
+{% macro render_unwrap_other(unwrapping, from_container, into_container) -%}
+{%- set out -%}
+{% if unwrapping.tp != '' and strict_check %}
+if not isinstance({{from_container}}, {{unwrapping.tp}}):
+    raise FieldValidationException('{{from_container.replace("'", "\\'")}}', '{{unwrapping.tp}}', str(type({{from_container}})))
+{% endif %}
+{% if unwrapping.tp != '' and explicit_cast %}
+{{into_container}} = {{unwrapping.tp}}({{from_container}})
+{% else %}
+{{into_container}} = {{from_container}}
+{% endif %}
+{%- endset %}
+{{out}}
+{%- endmacro %}
+
+
+{% macro render_unwrap_union(unwrapping, from_container, into_container) -%}
+{%- set out -%}
+{% for union_kind in unwrapping.union_kinds %}
+{% if loop.index > 1 %}el{% endif %}if isinstance({{from_container}}, {{union_kind.kind}}):
+{{render_unwrap(union_kind.unwrapping, from_container, into_container) | indent(4)}}
+{% endfor %}
+{% if strict_check %}
+else:
+    raise FieldValidationException('{{from_container.replace("'", "\\'")}}', 'dict', str(type({{from_container}})))
+{% elif explicit_cast %}
+else:
+{{render_unwrap(unwrapping.union_kinds[-1], from_container, into_container) | indent(4)}}
+{% else %}
+else:
+    {{into_container}} = fallback_unwrap({{from_container}})
+{% endif %}
+{%- endset %}
+{{out}}
+{%- endmacro %}
+
+
+{% macro render_unwrap(unwrapping, from_container, into_container) -%}
+{%- set out -%}
+{% if unwrapping.kind == 'dict' %}
+{{ render_unwrap_dict(unwrapping, from_container, into_container) }}
+{% elif unwrapping.kind == 'list' %}
+{{ render_unwrap_list(unwrapping, from_container, into_container) }}
+{% elif unwrapping.kind == 'object' %}
+{{ render_unwrap_object(unwrapping, from_container, into_container) }}
+{% elif unwrapping.kind == 'union' %}
+{{ render_unwrap_union(unwrapping, from_container, into_container) }}
+{% elif unwrapping.kind == 'fn' %}
+{{into_container}} = {{ unwrapping.fn }}({{from_container}})
+{% else %}
+{{ render_unwrap_other(unwrapping, from_container, into_container) }}
+{% endif %}
+{%- endset %}
+{{out}}
+{%- endmacro %}
+
+
+def {{funcname}}(from_data{% if from_type is not none%}: {{from_type}}{%endif%}) -> {% if into_type is none %}JsonObject{%else%}{{into_type}}{%endif%}:
+    """
+    {{from_type}} -> {{into_type}}
+    """
+    {{ render_unwrap(root_unwrap, 'from_data', 'ret') | indent(4) }}
+    return ret
+
+

src/megasniff/utils.py

@@ -71,3 +71,11 @@ def typename(tp: type) -> str:
     if get_origin(tp) is None and hasattr(tp, '__name__'):
         return tp.__name__
     return str(tp)
+
+
+def is_class_definition(obj):
+    return isinstance(obj, type) or inspect.isclass(obj)
+
+
+def hashname(obj) -> str:
+    return '_' + str(hash(obj)).replace('-', '_')

tests/test_basic_deflator.py

@@ -0,0 +1,77 @@
+from __future__ import annotations
+from dataclasses import dataclass
+from typing import Optional
+
+from megasniff.deflator import SchemaDeflatorGenerator
+from src.megasniff import SchemaInflatorGenerator
+
+
+def test_basic_deflator():
+    class A:
+        a: int
+
+        def __init__(self, a: int):
+            self.a = a
+
+    class B:
+        def __init__(self, b: int):
+            self.b = b
+
+    defl = SchemaDeflatorGenerator()
+    fn = defl.schema_to_deflator(A)
+    a = fn(A(42))
+
+    assert a['a'] == 42
+
+    fnb = defl.schema_to_deflator(B)
+    b = fnb(B(11))
+    assert len(b) == 0
+
+
+def test_unions():
+    @dataclass
+    class A:
+        a: int | str
+
+    defl = SchemaDeflatorGenerator()
+    fn = defl.schema_to_deflator(A)
+
+    a = fn(A(42))
+    assert a['a'] == 42
+    a = fn(A('42'))
+    assert a['a'] == '42'
+    a = fn(A('42a'))
+    assert a['a'] == '42a'
+
+
+@dataclass
+class CircA:
+    b: CircB
+
+
+@dataclass
+class CircB:
+    a: CircA | None
+
+
+def test_circular():
+    defl = SchemaDeflatorGenerator()
+    fn = defl.schema_to_deflator(CircA)
+    a = fn(CircA(CircB(CircA(CircB(None)))))
+
+    assert isinstance(a['b'], dict)
+    assert isinstance(a['b']['a'], dict)
+    assert a['b']['a']['b']['a'] is None
+
+
+def test_optional():
+    @dataclass
+    class C:
+        a: Optional[int] = None
+
+    defl = SchemaDeflatorGenerator()
+    fn = defl.schema_to_deflator(C)
+    c = fn(C())
+    assert c['a'] is None
+    c = fn(C(123))
+    assert c['a'] == 123

tests/test_explicit_cast_deflator.py

@@ -0,0 +1,94 @@
+from dataclasses import dataclass
+
+import pytest
+
+from megasniff import SchemaDeflatorGenerator
+from megasniff.exceptions import FieldValidationException
+
+
+def test_global_explicit_casts_basic():
+    class A:
+        a: int
+
+        def __init__(self, a):
+            self.a = a
+
+    defl = SchemaDeflatorGenerator(explicit_casts=True)
+    fn = defl.schema_to_deflator(A)
+    a = fn(A(42))
+
+    assert a['a'] == 42
+
+    a = fn(A(42.0))
+    assert a['a'] == 42
+
+    a = fn(A('42'))
+    assert a['a'] == 42
+
+    with pytest.raises(TypeError):
+        fn(A(['42']))
+
+
+def test_global_explicit_casts_basic_override():
+    class A:
+        a: int
+
+        def __init__(self, a):
+            self.a = a
+
+    defl = SchemaDeflatorGenerator(explicit_casts=False)
+    fn = defl.schema_to_deflator(A, explicit_casts_override=True)
+    a = fn(A(42))
+
+    assert a['a'] == 42
+
+    a = fn(A(42.0))
+    assert a['a'] == 42
+
+    a = fn(A('42'))
+    assert a['a'] == 42
+
+    with pytest.raises(TypeError):
+        fn(A(['42']))
+
+
+def test_global_explicit_casts_list():
+    @dataclass
+    class A:
+        a: list[int]
+
+    defl = SchemaDeflatorGenerator(explicit_casts=True)
+    fn = defl.schema_to_deflator(A)
+    a = fn(A([42]))
+
+    assert a['a'] == [42]
+
+    a = fn(A([42.0, 42]))
+    assert len(a['a']) == 2
+    assert a['a'][0] == 42
+    assert a['a'][1] == 42
+
+
+def test_global_explicit_casts_circular():
+    @dataclass
+    class A:
+        a: list[int]
+
+    @dataclass
+    class B:
+        b: list[A | int]
+
+    defl = SchemaDeflatorGenerator(explicit_casts=True)
+    fn = defl.schema_to_deflator(B)
+    b = fn(B([A([]), 42]))
+
+    assert len(b['b']) == 2
+    assert isinstance(b['b'][0], dict)
+    assert len(b['b'][0]['a']) == 0
+    assert isinstance(b['b'][1], int)
+
+    b = fn(B([42.0]))
+    assert b['b'][0] == 42
+
+    b = fn(B([A([1.1])]))
+    assert b['b'][0]['a'][0] == 1

tests/test_strict_mode_deflator.py

@@ -0,0 +1,88 @@
+from dataclasses import dataclass
+
+import pytest
+
+from megasniff import SchemaDeflatorGenerator
+from megasniff.exceptions import FieldValidationException
+
+
+def test_global_strict_mode_basic():
+    class A:
+        a: int
+
+        def __init__(self, a):
+            self.a = a
+
+    defl = SchemaDeflatorGenerator(strict_mode=True)
+    fn = defl.schema_to_deflator(A)
+    a = fn(A(42))
+
+    assert a['a'] == 42
+
+    with pytest.raises(FieldValidationException):
+        fn(A(42.0))
+    with pytest.raises(FieldValidationException):
+        fn(A('42'))
+    with pytest.raises(FieldValidationException):
+        fn(A(['42']))
+
+
+def test_global_strict_mode_basic_override():
+    class A:
+        a: int
+
+        def __init__(self, a):
+            self.a = a
+
+    defl = SchemaDeflatorGenerator(strict_mode=False)
+    fn = defl.schema_to_deflator(A, strict_mode_override=True)
+    a = fn(A(42))
+
+    assert a['a'] == 42
+
+    with pytest.raises(FieldValidationException):
+        fn(A(42.0))
+    with pytest.raises(FieldValidationException):
+        fn(A('42'))
+    with pytest.raises(FieldValidationException):
+        fn(A(['42']))
+
+
+def test_global_strict_mode_list():
+    @dataclass
+    class A:
+        a: list[int]
+
+    defl = SchemaDeflatorGenerator(strict_mode=True)
+    fn = defl.schema_to_deflator(A)
+    a = fn(A([42]))
+
+    assert a['a'] == [42]
+
+    with pytest.raises(FieldValidationException):
+        fn(A([42.0, 42]))
+
+
+def test_global_strict_mode_circular():
+    @dataclass
+    class A:
+        a: list[int]
+
+    @dataclass
+    class B:
+        b: list[A | int]
+
+    defl = SchemaDeflatorGenerator(strict_mode=True)
+    fn = defl.schema_to_deflator(B)
+    b = fn(B([A([]), 42]))
+
+    assert len(b['b']) == 2
+    assert isinstance(b['b'][0], dict)
+    assert len(b['b'][0]['a']) == 0
+    assert isinstance(b['b'][1], int)
+
+    with pytest.raises(FieldValidationException):
+        fn(B([42.0]))
+
+    with pytest.raises(FieldValidationException):
+        fn(B([A([1.1])]))