Add a way to filter fields

RELEASE.md

@@ -0,0 +1,33 @@
+Release type: minor
+
+This release adds a new method `get_fields` on the `Schema` class.
+You can use `get_fields` to hide certain field based on some conditions,
+for example:
+
+```python
+@strawberry.type
+class User:
+    name: str
+    email: str = strawberry.field(metadata={"tags": ["internal"]})
+
+
+@strawberry.type
+class Query:
+    user: User
+
+
+def public_field_filter(field: StrawberryField) -> bool:
+    return "internal" not in field.metadata.get("tags", [])
+
+
+class PublicSchema(strawberry.Schema):
+    def get_fields(
+        self, type_definition: StrawberryObjectDefinition
+    ) -> List[StrawberryField]:
+        return list(filter(public_field_filter, type_definition.fields))
+
+
+schema = PublicSchema(query=Query)
+```
+
+The schema here would only have the `name` field on the `User` type.

docs/types/schema.md

@@ -233,3 +233,43 @@ class StrawberryLogger:
 
         cls.logger.error(error, exc_info=error.original_error, **logger_kwargs)
 ```
+
+## Filtering/customising fields
+
+You can customise the fields that are exposed on a schema by subclassing the
+`Schema` class and overriding the `get_fields` method, for example you can use
+this to create different GraphQL APIs, such as a public and an internal API.
+Here's an example of this:
+
+```python
+@strawberry.type
+class User:
+    name: str
+    email: str = strawberry.field(metadata={"tags": ["internal"]})
+
+
+@strawberry.type
+class Query:
+    user: User
+
+
+def public_field_filter(field: StrawberryField) -> bool:
+    return "internal" not in field.metadata.get("tags", [])
+
+
+class PublicSchema(strawberry.Schema):
+    def get_fields(
+        self, type_definition: StrawberryObjectDefinition
+    ) -> List[StrawberryField]:
+        return list(filter(public_field_filter, type_definition.fields))
+
+
+schema = PublicSchema(query=Query)
+```
+
+<Note>
+
+The `get_fields` method is only called once when creating the schema, this is
+not intended to be used to dynamically customise the schema.
+
+</Note>

strawberry/schema/schema.py

@@ -100,7 +100,9 @@ def __init__(
             # TODO: check that the overrides are valid
             scalar_registry.update(cast(SCALAR_OVERRIDES_DICT_TYPE, scalar_overrides))
 
-        self.schema_converter = GraphQLCoreConverter(self.config, scalar_registry)
+        self.schema_converter = GraphQLCoreConverter(
+            self.config, scalar_registry, self.get_fields
+        )
         self.directives = directives
         self.schema_directives = list(schema_directives)
 
@@ -231,6 +233,11 @@ def get_directive_by_name(self, graphql_name: str) -> Optional[StrawberryDirecti
             None,
         )
 
+    def get_fields(
+        self, type_definition: StrawberryObjectDefinition
+    ) -> List[StrawberryField]:
+        return type_definition.fields
+
     async def execute(
         self,
         query: Optional[str],

strawberry/schema/schema_converter.py

@@ -109,6 +109,7 @@ def _get_thunk_mapping(
     type_definition: StrawberryObjectDefinition,
     name_converter: Callable[[StrawberryField], str],
     field_converter: FieldConverterProtocol[FieldType],
+    get_fields: Callable[[StrawberryObjectDefinition], List[StrawberryField]],
 ) -> Dict[str, FieldType]:
     """Create a GraphQL core `ThunkMapping` mapping of field names to field types.
 
@@ -123,7 +124,9 @@ def _get_thunk_mapping(
     """
     thunk_mapping: Dict[str, FieldType] = {}
 
-    for field in type_definition.fields:
+    fields = get_fields(type_definition)
+
+    for field in fields:
         field_type = field.type
 
         if field_type is UNRESOLVED:
@@ -178,10 +181,12 @@ def __init__(
         self,
         config: StrawberryConfig,
         scalar_registry: Dict[object, Union[ScalarWrapper, ScalarDefinition]],
+        get_fields: Callable[[StrawberryObjectDefinition], List[StrawberryField]],
     ):
         self.type_map: Dict[str, ConcreteType] = {}
         self.config = config
         self.scalar_registry = scalar_registry
+        self.get_fields = get_fields
 
     def from_argument(self, argument: StrawberryArgument) -> GraphQLArgument:
         argument_type = cast(
@@ -374,6 +379,7 @@ def get_graphql_fields(
             type_definition=type_definition,
             name_converter=self.config.name_converter.from_field,
             field_converter=self.from_field,
+            get_fields=self.get_fields,
         )
 
     def get_graphql_input_fields(
@@ -383,6 +389,7 @@ def get_graphql_input_fields(
             type_definition=type_definition,
             name_converter=self.config.name_converter.from_field,
             field_converter=self.from_input_field,
+            get_fields=self.get_fields,
         )
 
     def from_input_object(self, object_type: type) -> GraphQLInputObjectType:

tests/pyright/test_federation.py

@@ -29,13 +29,13 @@ def test_federation_type():
     results = run_pyright(CODE)
 
     assert results == [
-        Result(type="error", message='No parameter named "n"', line=16, column=6),
         Result(
             type="error",
             message='Argument missing for parameter "name"',
             line=16,
             column=1,
         ),
+        Result(type="error", message='No parameter named "n"', line=16, column=6),
         Result(
             type="information",
             message='Type of "User" is "type[User]"',
@@ -75,15 +75,15 @@ def test_federation_interface():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=12,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=12,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",
@@ -122,15 +122,15 @@ def test_federation_input():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=10,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=10,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",

tests/pyright/test_federation_fields.py

@@ -42,6 +42,12 @@ def test_pyright():
     results = run_pyright(CODE)
 
     assert results == [
+        Result(
+            type="error",
+            message='Argument missing for parameter "name"',
+            line=24,
+            column=1,
+        ),
         Result(
             type="error",
             message='No parameter named "n"',
@@ -51,7 +57,7 @@ def test_pyright():
         Result(
             type="error",
             message='Argument missing for parameter "name"',
-            line=24,
+            line=27,
             column=1,
         ),
         Result(
@@ -60,12 +66,6 @@ def test_pyright():
             line=27,
             column=11,
         ),
-        Result(
-            type="error",
-            message='Argument missing for parameter "name"',
-            line=27,
-            column=1,
-        ),
         Result(
             type="information",
             message='Type of "User" is "type[User]"',

tests/pyright/test_federation_params.py

@@ -23,14 +23,14 @@ def test_pyright():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=11,
-            column=11,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=11,
-            column=1,
+            column=11,
         ),
     ]

tests/pyright/test_fields.py

@@ -26,15 +26,15 @@ def test_pyright():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=11,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=11,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",

tests/pyright/test_fields_input.py

@@ -25,15 +25,15 @@ def test_pyright():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=11,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=11,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",

tests/pyright/test_fields_resolver.py

@@ -29,15 +29,15 @@ def test_pyright():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=15,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=15,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",

tests/pyright/test_fields_resolver_async.py

@@ -29,15 +29,15 @@ def test_pyright():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Argument missing for parameter "name"',
             line=15,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Argument missing for parameter "name"',
+            message='No parameter named "n"',
             line=15,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",

tests/pyright/test_params.py

@@ -29,12 +29,6 @@ def test_pyright():
     results = run_pyright(CODE)
 
     assert results == [
-        Result(
-            type="error",
-            message='No parameter named "n"',
-            line=16,
-            column=11,
-        ),
         Result(
             type="error",
             message='Argument missing for parameter "name"',
@@ -44,7 +38,7 @@ def test_pyright():
         Result(
             type="error",
             message='No parameter named "n"',
-            line=19,
+            line=16,
             column=11,
         ),
         Result(
@@ -53,4 +47,10 @@ def test_pyright():
             line=19,
             column=1,
         ),
+        Result(
+            type="error",
+            message='No parameter named "n"',
+            line=19,
+            column=11,
+        ),
     ]

tests/pyright/test_private.py

@@ -27,15 +27,15 @@ def test_pyright():
     assert results == [
         Result(
             type="error",
-            message='No parameter named "n"',
+            message='Arguments missing for parameters "name", "age"',
             line=12,
-            column=6,
+            column=1,
         ),
         Result(
             type="error",
-            message='Arguments missing for parameters "name", "age"',
+            message='No parameter named "n"',
             line=12,
-            column=1,
+            column=6,
         ),
         Result(
             type="information",