🐛 Fix response_model_include and response_model_exclude being ignored for sequence response models

fastapi/routing.py

@@ -45,6 +45,7 @@ from fastapi._compat import (
     ModelField,
     Undefined,
     lenient_issubclass,
+    value_is_sequence,
 )
 from fastapi.datastructures import Default, DefaultPlaceholder
 from fastapi.dependencies.models import Dependant
@@ -290,6 +291,16 @@ def _extract_endpoint_context(func: Any) -> EndpointContext:
     return ctx
 
 
+def _wrap_incex_for_sequence(incex: IncEx | None) -> IncEx | None:
+    # Pydantic interprets top-level include/exclude keys on a sequence type as
+    # item indices, so field names would be silently ignored. Wrap them in
+    # "__all__" to apply them to every item, unless indices or "__all__" are
+    # already used explicitly.
+    if incex and all(isinstance(key, str) and key != "__all__" for key in incex):
+        return {"__all__": incex}
+    return incex
+
+
 async def serialize_response(
     *,
     field: ModelField | None = None,
@@ -318,6 +329,9 @@ async def serialize_response(
                 body=response_content,
                 endpoint_ctx=ctx,
             )
+        if (include or exclude) and value_is_sequence(value):
+            include = _wrap_incex_for_sequence(include)
+            exclude = _wrap_incex_for_sequence(exclude)
         serializer = field.serialize_json if dump_json else field.serialize
         return serializer(
             value,

tests/test_response_model_include_exclude.py

@@ -1,4 +1,5 @@
 from fastapi import FastAPI
+from fastapi.responses import JSONResponse
 from fastapi.testclient import TestClient
 from pydantic import BaseModel
 
@@ -110,6 +111,73 @@ def mixed_dict():
     }
 
 
+@app.get(
+    "/list_include",
+    response_model=list[Model1],
+    response_model_include={"foo"},
+)
+def list_include():
+    return [
+        Model1(foo="list_include model foo", bar="list_include model bar"),
+        Model1(foo="list_include model2 foo", bar="list_include model2 bar"),
+    ]
+
+
+@app.get(
+    "/list_exclude",
+    response_model=list[Model1],
+    response_model_exclude={"bar"},
+)
+def list_exclude():
+    return [
+        Model1(foo="list_exclude model foo", bar="list_exclude model bar"),
+        Model1(foo="list_exclude model2 foo", bar="list_exclude model2 bar"),
+    ]
+
+
+@app.get(
+    "/list_exclude_nested",
+    response_model=list[Model2],
+    response_model_exclude={"ref": {"bar"}},
+)
+def list_exclude_nested():
+    return [
+        Model2(
+            ref=Model1(
+                foo="list_exclude_nested model foo",
+                bar="list_exclude_nested model bar",
+            ),
+            baz="list_exclude_nested model2 baz",
+        )
+    ]
+
+
+@app.get(
+    "/list_exclude_all",
+    response_model=list[Model1],
+    response_model_exclude={"__all__": {"bar"}},
+)
+def list_exclude_all():
+    return [
+        Model1(foo="list_exclude_all model foo", bar="list_exclude_all model bar"),
+    ]
+
+
+@app.get(
+    "/list_exclude_response_class",
+    response_model=list[Model1],
+    response_model_exclude={"bar"},
+    response_class=JSONResponse,
+)
+def list_exclude_response_class():
+    return [
+        Model1(
+            foo="list_exclude_response_class model foo",
+            bar="list_exclude_response_class model bar",
+        ),
+    ]
+
+
 client = TestClient(app)
 
 
@@ -173,3 +241,44 @@ def test_nested_include_mixed_dict():
             "ref": {"foo": "mixed_dict model foo", "bar": "mixed_dict model bar"},
         },
     }
+
+
+def test_list_include():
+    response = client.get("/list_include")
+    assert response.status_code == 200, response.text
+    assert response.json() == [
+        {"foo": "list_include model foo"},
+        {"foo": "list_include model2 foo"},
+    ]
+
+
+def test_list_exclude():
+    response = client.get("/list_exclude")
+    assert response.status_code == 200, response.text
+    assert response.json() == [
+        {"foo": "list_exclude model foo"},
+        {"foo": "list_exclude model2 foo"},
+    ]
+
+
+def test_list_exclude_nested():
+    response = client.get("/list_exclude_nested")
+    assert response.status_code == 200, response.text
+    assert response.json() == [
+        {
+            "ref": {"foo": "list_exclude_nested model foo"},
+            "baz": "list_exclude_nested model2 baz",
+        }
+    ]
+
+
+def test_list_exclude_all():
+    response = client.get("/list_exclude_all")
+    assert response.status_code == 200, response.text
+    assert response.json() == [{"foo": "list_exclude_all model foo"}]
+
+
+def test_list_exclude_response_class():
+    response = client.get("/list_exclude_response_class")
+    assert response.status_code == 200, response.text
+    assert response.json() == [{"foo": "list_exclude_response_class model foo"}]