From 102d56aa601fdc6ced89101f92bfc4dcabd05d4c Mon Sep 17 00:00:00 2001
From: Dawid Kraczkowski <dawid.kraczkowski@gmail.com>
Date: Wed, 8 Nov 2023 07:18:03 +0100
Subject: [PATCH] Add mapping support in Encoder and Decoder

---
 README.md             |  9 +++++++++
 chili/decoder.py      | 10 +++++-----
 chili/encoder.py      |  6 ++++--
 tests/test_decoder.py | 34 +++++++++++++++++++++++++++++++++-
 tests/test_encoder.py | 33 +++++++++++++++++++++++++++++----
 5 files changed, 80 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index dbb0719..8d67f57 100644
--- a/README.md
+++ b/README.md
@@ -461,6 +461,15 @@ assert encoded == {
 }
 ```
 
+Alternatively you can set mapper in `Encoder` and `Decoder` classes:
+
+```python
+encoder = Encoder[Pet](mapper=mapper)
+
+pet = Pet("Max", 3, ["cute", "furry"])
+encoded = encoder.encode(pet)
+```
+
 ## Error handling
 The library raises errors if an invalid type is passed to the Encoder or Decoder, or if an invalid dictionary is passed to the Decoder.
 
diff --git a/chili/decoder.py b/chili/decoder.py
index 53dbfa7..4edaa80 100644
--- a/chili/decoder.py
+++ b/chili/decoder.py
@@ -536,9 +536,10 @@ class Decoder(Generic[T]):
     __generic__: Type[T]
     _decoders: Dict[str, TypeDecoder]
 
-    def __init__(self, decoders: Union[TypeDecoders, Dict[Any, TypeDecoder]] = None):
+    def __init__(self, decoders: Union[TypeDecoders, Dict[Any, TypeDecoder]] = None, mapper: Optional[Mapper] = None):
         if decoders and not isinstance(decoders, TypeDecoders):
             decoders = TypeDecoders(decoders)
+        self.mapper = mapper
         self.type_decoders = decoders
 
     @property
@@ -554,6 +555,8 @@ def decode(self, obj: Dict[str, StateObject]) -> T:
         if hasattr(self.__generic__, _DECODE_MAPPER):
             mapper = getattr(self.__generic__, _DECODE_MAPPER)
             obj = mapper.map(obj)
+        elif self.mapper:
+            obj = self.mapper.map(obj)
 
         for key, prop in self.schema.items():
             if key not in obj:
@@ -600,10 +603,7 @@ def __class_getitem__(cls, item: Type) -> Type[Decoder]:  # noqa: E501
 
 
 def decode(
-    obj: StateObject,
-    a_type: Type[T],
-    decoders: Union[TypeDecoders, Dict[Any, TypeDecoder]] = None,
-    force: bool = False
+    obj: StateObject, a_type: Type[T], decoders: Union[TypeDecoders, Dict[Any, TypeDecoder]] = None, force: bool = False
 ) -> T:
     if decoders and not isinstance(decoders, TypeDecoders):
         decoders = TypeDecoders(decoders)
diff --git a/chili/encoder.py b/chili/encoder.py
index 5107c2e..a08b70b 100644
--- a/chili/encoder.py
+++ b/chili/encoder.py
@@ -443,10 +443,10 @@ class Encoder(Generic[T]):
     __generic__: Type[T]
     _encoders: Dict[str, TypeEncoder]
 
-    def __init__(self, encoders: Union[Dict, TypeEncoders] = None):
+    def __init__(self, encoders: Union[Dict, TypeEncoders] = None, mapper: Optional[Mapper] = None):
         if encoders and not isinstance(encoders, TypeEncoders):
             encoders = TypeEncoders(encoders)
-
+        self.mapper = mapper
         self.type_encoders = encoders
 
     def encode(self, obj: T) -> StateObject:
@@ -466,6 +466,8 @@ def encode(self, obj: T) -> StateObject:
         if hasattr(self.__generic__, _ENCODE_MAPPER):
             mapper = getattr(self.__generic__, _ENCODE_MAPPER)
             return mapper.map(result)
+        elif self.mapper:
+            return self.mapper.map(result)
 
         return result
 
diff --git a/tests/test_decoder.py b/tests/test_decoder.py
index fe24d18..7643561 100644
--- a/tests/test_decoder.py
+++ b/tests/test_decoder.py
@@ -1,4 +1,4 @@
-from chili import Decoder, decodable
+from chili import Decoder, Mapper, decodable
 
 
 def test_can_instantiate() -> None:
@@ -13,3 +13,35 @@ class Example:
     # then
     assert isinstance(instance, Decoder)
     assert instance.__generic__ == Example
+
+
+def test_dencode_and_map() -> None:
+    # given
+    class Example:
+        name: str
+        age: int
+
+        def __init__(self, name: str, age: int):
+            self.name = name
+            self.age = age
+
+    mapper = Mapper(
+        {
+            "name": "_name",
+            "age": "_age",
+        }
+    )
+    encoder = Decoder[Example](mapper=mapper)
+
+    # when
+    data = encoder.decode(
+        {
+            "_name": "Bobik",
+            "_age": 11,
+        }
+    )
+
+    # then
+    assert isinstance(data, Example)
+    assert data.name == "Bobik"
+    assert data.age == 11
diff --git a/tests/test_encoder.py b/tests/test_encoder.py
index 54ecdee..afc9166 100644
--- a/tests/test_encoder.py
+++ b/tests/test_encoder.py
@@ -1,9 +1,6 @@
 from collections import UserString
 
-import pytest
-
-from chili import Encoder, encodable
-from chili.error import EncoderError
+from chili import Encoder, Mapper, encodable
 
 
 def test_can_instantiate() -> None:
@@ -63,3 +60,31 @@ def __init__(self, name: ExampleName, age: int):
         "name": "bob",
         "age": 33,
     }
+
+
+def test_encode_and_map() -> None:
+    # given
+    class Example:
+        name: str
+        age: int
+
+        def __init__(self, name: str, age: int):
+            self.name = name
+            self.age = age
+
+    mapper = Mapper(
+        {
+            "_name": "name",
+            "_age": "age",
+        }
+    )
+    encoder = Encoder[Example](mapper=mapper)
+
+    # when
+    data = encoder.encode(Example("Bobik", 11))
+
+    # then
+    assert data == {
+        "_name": "Bobik",
+        "_age": 11,
+    }