Add a failing test for computed properties on export

Author: Henry Walshaw

tests/models.py

@@ -2,7 +2,7 @@
 from typing import Optional
 
 import pydantic
-from pydantic import Field
+from pydantic import Field, computed_field
 
 
 class User(pydantic.BaseModel):
@@ -56,3 +56,19 @@ def parse_end_date(cls, value):
 class ExcludedPassword(pydantic.BaseModel):
     username: str = "Wagstaff"
     password: str = Field(default="swordfish", exclude=True)
+
+
+class ComputedPropertyField(pydantic.BaseModel):
+    username: str = "Groucho"
+
+    @computed_field
+    def email(self) -> str:
+        return f"{self.username.lower()}@marx.bros"
+
+
+class ComputedPropertyWithAlias(pydantic.BaseModel):
+    username: str = "Harpo"
+
+    @computed_field(alias="e")
+    def email(self) -> str:
+        return f"{self.username.lower()}@marx.bros"

tests/test_basemodel_csv_writer.py

@@ -4,7 +4,14 @@
 
 from pydantic_csv import BasemodelCSVWriter
 
-from .models import ExcludedPassword, NonBaseModelUser, SimpleUser, User
+from .models import (
+    ComputedPropertyField,
+    ComputedPropertyWithAlias,
+    ExcludedPassword,
+    NonBaseModelUser,
+    SimpleUser,
+    User,
+)
 
 
 def test_create_csv_file(users_as_csv_buffer, users_from_csv):
@@ -60,3 +67,22 @@ def test_excluded_field():
     w.write()
 
     assert output.getvalue() == "username\r\nWagstaff\r\n"
+
+
+@pytest.mark.parametrize(
+    ("model", "use_alias", "expected_output"),
+    [
+        (ComputedPropertyField, True, "username,email\r\nGroucho,[email protected]\r\n"),
+        (ComputedPropertyWithAlias, True, "username,e\r\nHarpo,[email protected]\r\n"),
+        (ComputedPropertyField, False, "username,email\r\nGroucho,[email protected]\r\n"),
+        (ComputedPropertyWithAlias, False, "username,email\r\nHarpo,[email protected]\r\n"),
+    ],
+)
+def test_computed_property_included(model, use_alias, expected_output):
+    output = io.StringIO()
+    user = model()
+
+    w = BasemodelCSVWriter(output, [user], model, use_alias=use_alias)
+    w.write()
+
+    assert output.getvalue() == expected_output