Added better description for using mapper with Pydancit and TortoiseORM, added better type casting, simplified test cases

Author: Andrii Nikolaienko

CHANGELOG.md

@@ -1,3 +1,7 @@
+1.0.4 - 2022/07/25
+* Added better description for usage with Pydantic and TortoiseORM
+* Improved type support
+
 1.0.3 - 2022/07/24
 * Fixed issue with dictionary collection: https://github.com/anikolaienko/py-automapper/issues/4
 

README.md

@@ -3,7 +3,7 @@
 # py-automapper
 
 **Version**
-1.0.3
+1.0.4
 
 **Author**
 anikolaienko
@@ -33,6 +33,9 @@ Table of Contents:
   - [Different field names](#different-field-names)
   - [Overwrite field value in mapping](#overwrite-field-value-in-mapping)
   - [Extensions](#extensions)
+  - [Pydantic/FastAPI Support](#pydanticfastapi-support)
+  - [TortoiseORM Support](#tortoiseorm-support)
+  - [Create your own extension (Advanced)](#create-your-own-extension-advanced)
 
 # Versions
 Check [CHANGELOG.md](/CHANGELOG.md)
@@ -120,14 +123,81 @@ print(vars(public_user_info))
 # {'full_name': 'John Cusack', 'profession': 'engineer'}
 ```
 
+
 ## Extensions
-`py-automapper` has few predefined extensions for mapping to classes for frameworks:
+`py-automapper` has few predefined extensions for mapping support to classes for frameworks:
 * [FastAPI](https://github.com/tiangolo/fastapi) and [Pydantic](https://github.com/samuelcolvin/pydantic)
 * [TortoiseORM](https://github.com/tortoise/tortoise-orm)
 
+## Pydantic/FastAPI Support
+Out of the box Pydantic models support:
+```python
+from pydantic import BaseModel
+from typing import List
+from automapper import mapper
+
+class UserInfo(BaseModel):
+    id: int
+    full_name: str
+    public_name: str
+    hobbies: List[str]
+
+class PublicUserInfo(BaseModel):
+    id: int
+    public_name: str
+    hobbies: List[str]
+
+obj = UserInfo(
+    id=2,
+    full_name="Danny DeVito",
+    public_name="dannyd",
+    hobbies=["acting", "comedy", "swimming"]
+)
+
+result = default_mapper.to(PublicUserInfo).map(obj)
+# same behaviour with preregistered mapping
+
+print(vars(result))
+# {'id': 2, 'public_name': 'dannyd', 'hobbies': ['acting', 'comedy', 'swimming']}
+```
+
+## TortoiseORM Support
+Out of the box TortoiseORM models support:
+```python
+from tortoise import Model, fields
+from automapper import mapper
+
+class UserInfo(Model):
+    id = fields.IntField(pk=True)
+    full_name = fields.TextField()
+    public_name = fields.TextField()
+    hobbies = fields.JSONField()
+
+class PublicUserInfo(Model):
+    id = fields.IntField(pk=True)
+    public_name = fields.TextField()
+    hobbies = fields.JSONField()
+
+obj = UserInfo(
+    id=2,
+    full_name="Danny DeVito",
+    public_name="dannyd",
+    hobbies=["acting", "comedy", "swimming"],
+    using_db=True
+)
+
+result = default_mapper.to(PublicUserInfo).map(obj)
+# same behaviour with preregistered mapping
+
+# filtering out protected fields that start with underscore "_..."
+print({key: value for key, value in vars(result) if not key.startswith("_")})
+# {'id': 2, 'public_name': 'dannyd', 'hobbies': ['acting', 'comedy', 'swimming']}
+```
+
+## Create your own extension (Advanced)
 When you first time import `mapper` from `automapper` it checks default extensions and if modules are found for these extensions, then they will be automatically loaded for default `mapper` object.
 
-What does extension do? To know what fields in Target class are available for mapping `py-automapper` need to extract the list of these fields. There is no generic way to do that for all Python objects. For this purpose `py-automapper` uses extensions.
+**What does extension do?** To know what fields in Target class are available for mapping, `py-automapper` needs to know how to extract the list of fields. There is no generic way to do that for all Python objects. For this purpose `py-automapper` uses extensions.
 
 List of default extensions can be found in [/automapper/extensions](/automapper/extensions) folder. You can take a look how it's done for a class with `__init__` method or for Pydantic or TortoiseORM models.
 

automapper/mapper.py

@@ -301,7 +301,7 @@ def _map_common(
 
         _visited_stack.remove(obj_id)
 
-        return target_cls(**mapped_values)  # type: ignore [call-arg]
+        return cast(target_cls, target_cls(**mapped_values))  # type: ignore [call-arg, redundant-cast, valid-type]
 
     def to(self, target_cls: Type[T]) -> MappingWrapper[T]:
         """Specify target class to map source object to"""

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "py-automapper"
-version = "1.0.3"
+version = "1.0.4"
 description = "Library for automatically mapping one object to another"
 authors = ["Andrii Nikolaienko <anikolaienko14@gmail.com>"]
 license = "MIT"

tests/test_automapper_sample.py

@@ -22,7 +22,7 @@ def __init__(self, full_name: str, profession: str):
 
 def test_map__field_with_same_name():
     user_info = UserInfo("John Malkovich", 35, "engineer")
-    public_user_info: PublicUserInfo = mapper.to(PublicUserInfo).map(
+    public_user_info = mapper.to(PublicUserInfo).map(
         user_info, fields_mapping={"full_name": user_info.name}
     )
 
@@ -58,7 +58,7 @@ def test_map__field_with_different_name_register():
 def test_map__override_field_value():
     try:
         user_info = UserInfo("John Malkovich", 35, "engineer")
-        public_user_info: PublicUserInfo = mapper.to(PublicUserInfo).map(
+        public_user_info = mapper.to(PublicUserInfo).map(
             user_info, fields_mapping={"name": "John Cusack"}
         )
 

tests/test_for_pydantic_extention.py

@@ -1,40 +1,53 @@
-from dataclasses import dataclass
+from typing import List
 from unittest import TestCase
 
 import pytest
 from pydantic import BaseModel
 
-from automapper import mapper as global_mapper, Mapper, MappingError
+from automapper import mapper as default_mapper, Mapper, MappingError
 
 
-@dataclass
-class SourceClass:
+class UserInfo(BaseModel):
     id: int
-    name: str
+    full_name: str
+    public_name: str
+    hobbies: List[str]
 
 
-class TargetModel(BaseModel):
+class PublicUserInfo(BaseModel):
     id: int
-    name: str
+    public_name: str
+    hobbies: List[str]
 
 
 class PydanticExtensionTest(TestCase):
-    """These scenario are known for ORM systems.
-    e.g. Model classes in Tortoise ORM
-    """
+    """These scenario are known for FastAPI Framework models and Pydantic models in general."""
 
     def setUp(self) -> None:
         self.mapper = Mapper()
 
-    def test_map__fails_for_tortoise_mapping(self):
-        obj = SourceClass(15, "This is a test text")
+    def test_map__fails_for_pydantic_mapping(self):
+        obj = UserInfo(
+            id=2,
+            full_name="Danny DeVito",
+            public_name="dannyd",
+            hobbies=["acting", "comedy", "swimming"],
+        )
         with pytest.raises(MappingError):
-            self.mapper.to(TargetModel).map(obj)
-
-    def test_map__global_mapper_works_with_provided_tortoise_extension(self):
-        obj = SourceClass(17, "Test obj name")
-
-        result = global_mapper.to(TargetModel).map(obj)
-
-        assert result.id == 17
-        assert result.name == "Test obj name"
+            self.mapper.to(PublicUserInfo).map(obj)
+
+    def test_map__global_mapper_works_with_provided_pydantic_extension(self):
+        obj = UserInfo(
+            id=2,
+            full_name="Danny DeVito",
+            public_name="dannyd",
+            hobbies=["acting", "comedy", "swimming"],
+        )
+
+        result = default_mapper.to(PublicUserInfo).map(obj)
+
+        assert result.id == 2
+        assert result.public_name == "dannyd"
+        assert set(result.hobbies) == set(["acting", "comedy", "swimming"])
+        with pytest.raises(AttributeError):
+            getattr(result, "full_name")

tests/test_for_tortoise_extention.py

@@ -1,21 +1,22 @@
-from dataclasses import dataclass
 from unittest import TestCase
 
 import pytest
 from tortoise import Model, fields
 
-from automapper import mapper as global_mapper, Mapper, MappingError
+from automapper import mapper as default_mapper, Mapper, MappingError
 
 
-@dataclass
-class SourceClass:
-    id: int
-    name: str
+class UserInfo(Model):
+    id = fields.IntField(pk=True)
+    full_name = fields.TextField()
+    public_name = fields.TextField()
+    hobbies = fields.JSONField()
 
 
-class TargetModel(Model):
+class PublicUserInfo(Model):
     id = fields.IntField(pk=True)
-    name = fields.TextField()
+    public_name = fields.TextField()
+    hobbies = fields.JSONField()
 
 
 class TortoiseORMExtensionTest(TestCase):
@@ -27,14 +28,28 @@ def setUp(self) -> None:
         self.mapper = Mapper()
 
     def test_map__fails_for_tortoise_mapping(self):
-        obj = SourceClass(15, "This is a test text")
+        obj = UserInfo(
+            id=2,
+            full_name="Danny DeVito",
+            public_name="dannyd",
+            hobbies=["acting", "comedy", "swimming"],
+        )
         with pytest.raises(MappingError):
-            self.mapper.to(TargetModel).map(obj)
+            self.mapper.to(PublicUserInfo).map(obj)
 
     def test_map__global_mapper_works_with_provided_tortoise_extension(self):
-        obj = SourceClass(17, "Test obj name")
-
-        result = global_mapper.to(TargetModel).map(obj)
-
-        assert result.id == 17
-        assert result.name == "Test obj name"
+        obj = UserInfo(
+            id=2,
+            full_name="Danny DeVito",
+            public_name="dannyd",
+            hobbies=["acting", "comedy", "swimming"],
+            using_db=True,
+        )
+
+        result = default_mapper.to(PublicUserInfo).map(obj)
+
+        assert result.id == 2
+        assert result.public_name == "dannyd"
+        assert set(result.hobbies) == set(["acting", "comedy", "swimming"])
+        with pytest.raises(AttributeError):
+            getattr(result, "full_name")