From ad7862f03254f41b0519977b00fb3db3d331a0bc Mon Sep 17 00:00:00 2001
From: Eric Jolibois <em.jolibois@gmail.com>
Date: Sat, 13 Feb 2021 12:26:43 +0100
Subject: [PATCH] fix: keep order of fields with `BaseModel.construct()`
 (#2282)

* fix: keep order of fields with `BaseModel.construct()`

closes #2281

* chore: keep extra fields in construct

thanks @layday!
---
 changes/2281-PrettyWood.md |  1 +
 pydantic/main.py           |  9 +++++++--
 tests/test_construction.py | 22 ++++++++++++++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 changes/2281-PrettyWood.md

diff --git a/changes/2281-PrettyWood.md b/changes/2281-PrettyWood.md
new file mode 100644
index 0000000..b554eb5
--- /dev/null
+++ b/changes/2281-PrettyWood.md
@@ -0,0 +1 @@
+fix: keep order of fields with `BaseModel.construct()`
diff --git a/pydantic/main.py b/pydantic/main.py
index a53786a..a3c1c0b 100644
--- a/pydantic/main.py
+++ b/pydantic/main.py
@@ -611,10 +611,15 @@ class BaseModel(Representation, metaclass=ModelMetaclass):
         """
         Creates a new model setting __dict__ and __fields_set__ from trusted or pre-validated data.
         Default values are respected, but no other validation is performed.
+        Behaves as if `Config.extra = 'allow'` was set since it adds all passed values
         """
         m = cls.__new__(cls)
-        # default field values
-        fields_values = {name: field.get_default() for name, field in cls.__fields__.items() if not field.required}
+        fields_values: Dict[str, Any] = {}
+        for name, field in cls.__fields__.items():
+            if name in values:
+                fields_values[name] = values[name]
+            elif not field.required:
+                fields_values[name] = field.get_default()
         fields_values.update(values)
         object_setattr(m, '__dict__', fields_values)
         if _fields_set is None:
diff --git a/tests/test_construction.py b/tests/test_construction.py
index 0065715..1e473c3 100644
--- a/tests/test_construction.py
+++ b/tests/test_construction.py
@@ -35,6 +35,28 @@ def test_construct_fields_set():
     assert m.dict() == {'a': 3, 'b': -1}
 
 
+def test_construct_allow_extra():
+    """construct() should allow extra fields"""
+
+    class Foo(BaseModel):
+        x: int
+
+    assert Foo.construct(x=1, y=2).dict() == {'x': 1, 'y': 2}
+
+
+def test_construct_keep_order():
+    class Foo(BaseModel):
+        a: int
+        b: int = 42
+        c: float
+
+    instance = Foo(a=1, b=321, c=3.14)
+    instance_construct = Foo.construct(**instance.dict())
+    assert instance == instance_construct
+    assert instance.dict() == instance_construct.dict()
+    assert instance.json() == instance_construct.json()
+
+
 def test_large_any_str():
     class Model(BaseModel):
         a: bytes