Better pydantic validation example

Author: sayanarijit

README.md

@@ -68,23 +68,30 @@ with engine.connect() as conn:
 ### With Pydantic Validation
 
 ```python
-
-from pydantic import BaseModel, Field
-
-from sqla_fancy_core import TableFactory
-
-tf = TableFactory()
+def field(col, default=...):
+    return col.info["field"](default)
 
 # Define a table
 class User:
-    name = tf.string("name", info={"field": Field(..., max_length=5)})
+    name = tf.string(
+        "name", info={"field": lambda default: Field(default, max_length=5)}
+    )
     Table = tf("author")
 
 # Define a pydantic schema
 class CreateUser(BaseModel):
-    name: str = User.name.info["field"]
+    name: str = field(User.name)
+
+# Define a pydantic schema
+class UpdateUser(BaseModel):
+    name: str | None = field(User.name, None)
 
 assert CreateUser(name="John").model_dump() == {"name": "John"}
+assert UpdateUser(name="John").model_dump() == {"name": "John"}
+assert UpdateUser().model_dump(exclude_unset=True) == {}
+
+with pytest.raises(ValueError):
+    CreateUser()
 with pytest.raises(ValueError):
-    CreateUser(name="John Doe")
+    UpdateUser(name="John Doe")
 ```

tests/test_field.py

@@ -0,0 +1,36 @@
+import pytest
+
+
+def test_field():
+    from pydantic import BaseModel, Field
+
+    from sqla_fancy_core import TableFactory
+
+    tf = TableFactory()
+
+    def field(col, default=...):
+        return col.info["field"](default)
+
+    # Define a table
+    class User:
+        name = tf.string(
+            "name", info={"field": lambda default: Field(default, max_length=5)}
+        )
+        Table = tf("author")
+
+    # Define a pydantic schema
+    class CreateUser(BaseModel):
+        name: str = field(User.name)
+
+    # Define a pydantic schema
+    class UpdateUser(BaseModel):
+        name: str | None = field(User.name, None)
+
+    assert CreateUser(name="John").model_dump() == {"name": "John"}
+    assert UpdateUser(name="John").model_dump() == {"name": "John"}
+    assert UpdateUser().model_dump(exclude_unset=True) == {}
+
+    with pytest.raises(ValueError):
+        CreateUser()
+    with pytest.raises(ValueError):
+        UpdateUser(name="John Doe")

tests/test_table_factory.py

@@ -1,6 +1,3 @@
-import pytest
-
-
 def test_table_factory():
     import sqlalchemy as sa
 
@@ -58,24 +55,3 @@ class Book:
         )
         result = conn.execute(qry).fetchall()
         assert result == [("John Doe", "My Book")], result
-
-
-def test_field():
-    from pydantic import BaseModel, Field
-
-    from sqla_fancy_core import TableFactory
-
-    tf = TableFactory()
-
-    # Define a table
-    class User:
-        name = tf.string("name", info={"field": Field(..., max_length=5)})
-        Table = tf("author")
-
-    # Define a pydantic schema
-    class CreateUser(BaseModel):
-        name: str = User.name.info["field"]
-
-    assert CreateUser(name="John").model_dump() == {"name": "John"}
-    with pytest.raises(ValueError):
-        CreateUser(name="John Doe")