Add support for refetchable interfaces

Summary:
In https://fb.workplace.com/groups/relay.support/permalink/10086229424758915/, it was revealed that fetchable interfaces are not currently supported by relay, even though they could be.

* Add support for (re) fetchable interfaces

Reviewed By: davidmccabe

Differential Revision: D41747533

fbshipit-source-id: 1cf1ae88645c9b9dcbff7e97a2060232a9a6550d

compiler/crates/relay-transforms/src/refetchable_fragment/fetchable_query_generator.rs

@@ -125,23 +125,33 @@ fn get_fetchable_field_name(
     fragment: &FragmentDefinition,
     schema: &SDLSchema,
 ) -> DiagnosticsResult<Option<StringKey>> {
-    if let Type::Object(id) = fragment.type_condition {
-        let object = schema.object(id);
-        if let Some(fetchable) = object.directives.named(CONSTANTS.fetchable) {
-            let field_name_arg = fetchable.arguments.named(CONSTANTS.field_name);
-            if let Some(field_name_arg) = field_name_arg {
-                if let Some(value) = field_name_arg.value.get_string_literal() {
-                    return Ok(Some(value));
-                }
+    let fetchable_directive = match fragment.type_condition {
+        Type::Interface(interface_id) => {
+            let interface = schema.interface(interface_id);
+            interface.directives.named(CONSTANTS.fetchable)
+        }
+        Type::Object(object_id) => {
+            let object = schema.object(object_id);
+            object.directives.named(CONSTANTS.fetchable)
+        }
+        _ => None,
+    };
+
+    if let Some(fetchable) = fetchable_directive {
+        let field_name_arg = fetchable.arguments.named(CONSTANTS.field_name);
+        if let Some(field_name_arg) = field_name_arg {
+            if let Some(value) = field_name_arg.value.get_string_literal() {
+                return Ok(Some(value));
             }
-            return Err(vec![Diagnostic::error(
-                ValidationMessage::InvalidRefetchDirectiveDefinition {
-                    fragment_name: fragment.name.item.0,
-                },
-                fragment.name.location,
-            )]);
         }
+        return Err(vec![Diagnostic::error(
+            ValidationMessage::InvalidRefetchDirectiveDefinition {
+                fragment_name: fragment.name.item,
+            },
+            fragment.name.location,
+        )]);
     }
+
     Ok(None)
 }
 
@@ -231,6 +241,6 @@ fn enforce_selections_with_id_field(
 
 pub const FETCHABLE_QUERY_GENERATOR: QueryGenerator = QueryGenerator {
     // T138625502 we should support interfaces and maybe unions
-    description: "server objects with the @fetchable directive",
+    description: "server objects and interfaces with the @fetchable directive",
     build_refetch_operation,
 };

compiler/crates/relay-transforms/src/refetchable_fragment/validation_message.rs

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+use graphql_ir::FragmentDefinitionName;
 use graphql_ir::VariableName;
 use intern::string_key::StringKey;
 use thiserror::Error;
@@ -76,10 +77,13 @@ pub(super) enum ValidationMessage {
     )]
     InvalidViewerSchemaForRefetchableFragmentOnViewer { fragment_name: StringKey },
 
+    // T139416294 this error message doesn't appear to be accurate
     #[error(
-        "Invalid use of @refetchable with @connection in fragment '{fragment_name}', check that your schema defines a `directive @fetchable(field_name: String!) on OBJECT`."
+        "Invalid use of @refetchable with @connection in fragment '{fragment_name}', check that your schema defines a `directive @fetchable(field_name: String!) on OBJECT` or on `INTERFACE`."
     )]
-    InvalidRefetchDirectiveDefinition { fragment_name: StringKey },
+    InvalidRefetchDirectiveDefinition {
+        fragment_name: FragmentDefinitionName,
+    },
 
     #[error(
         "Invalid use of @refetchable on fragment '{fragment_name}', the type '{type_name}' is @fetchable but the identifying field '{identifier_field_name}' does not have type 'ID'."

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/fragment-on-interface-which-implementations-not-implement-node.invalid.expected

@@ -9,7 +9,7 @@ fragment UserName on UserNameRenderable
  - the Viewer type
  - the Query type
  - the Node interface, object types that implement the Node interface, interfaces whose implementing objects all implement Node, and unions whose members all implement Node
- - server objects with the @fetchable directive
+ - server objects and interfaces with the @fetchable directive
 
   fragment-on-interface-which-implementations-not-implement-node.invalid.graphql:2:10
     1 │ # expected-to-throw

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface-all-implementing-types-impl-node.expected

@@ -0,0 +1,47 @@
+==================================== INPUT ====================================
+fragment RefetchableFragment on RefetchableInterface
+  @refetchable(queryName: "RefetchableFragmentQuery") {
+  id
+}
+
+# %extensions%
+
+interface RefetchableInterface @fetchable(field_name: "id") {
+    id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterface(id: ID!): RefetchableInterface
+}
+
+type ConcreteTypeImplementingRefetchableInterface implements RefetchableInterface & Node {
+  id: ID!
+}
+==================================== OUTPUT ===================================
+query RefetchableFragmentQuery(
+  $id: ID!
+) @__RefetchableDerivedFromMetadata
+# RefetchableDerivedFromMetadata(
+#     FragmentDefinitionName(
+#         "RefetchableFragment",
+#     ),
+# )
+ {
+  node(id: $id) {
+    ...RefetchableFragment
+  }
+}
+
+fragment RefetchableFragment on RefetchableInterface @refetchable(queryName: "RefetchableFragmentQuery") @__RefetchableMetadata
+# RefetchableMetadata {
+#     operation_name: "RefetchableFragmentQuery",
+#     path: [
+#         "node",
+#     ],
+#     identifier_field: Some(
+#         "id",
+#     ),
+# }
+ {
+  id
+}

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface-all-implementing-types-impl-node.graphql

@@ -0,0 +1,18 @@
+fragment RefetchableFragment on RefetchableInterface
+  @refetchable(queryName: "RefetchableFragmentQuery") {
+  id
+}
+
+# %extensions%
+
+interface RefetchableInterface @fetchable(field_name: "id") {
+    id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterface(id: ID!): RefetchableInterface
+}
+
+type ConcreteTypeImplementingRefetchableInterface implements RefetchableInterface & Node {
+  id: ID!
+}

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface-but-no-implementing-types.expected

@@ -0,0 +1,46 @@
+==================================== INPUT ====================================
+# Because there are no implementing types, "all implementing types impl Node"
+# is true, so we generated a Node refetch query.
+fragment RefetchableFragmentFoo on RefetchableInterfaceFoo
+  @refetchable(queryName: "RefetchableFragmentFooQuery") {
+  id
+}
+
+
+# %extensions%
+
+interface RefetchableInterfaceFoo @fetchable(field_name: "id") {
+    id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterfaceFoo(id: ID!): RefetchableInterfaceFoo
+}
+==================================== OUTPUT ===================================
+query RefetchableFragmentFooQuery(
+  $id: ID!
+) @__RefetchableDerivedFromMetadata
+# RefetchableDerivedFromMetadata(
+#     FragmentDefinitionName(
+#         "RefetchableFragmentFoo",
+#     ),
+# )
+ {
+  node(id: $id) {
+    ...RefetchableFragmentFoo
+  }
+}
+
+fragment RefetchableFragmentFoo on RefetchableInterfaceFoo @refetchable(queryName: "RefetchableFragmentFooQuery") @__RefetchableMetadata
+# RefetchableMetadata {
+#     operation_name: "RefetchableFragmentFooQuery",
+#     path: [
+#         "node",
+#     ],
+#     identifier_field: Some(
+#         "id",
+#     ),
+# }
+ {
+  id
+}

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface-but-no-implementing-types.graphql

@@ -0,0 +1,17 @@
+# Because there are no implementing types, "all implementing types impl Node"
+# is true, so we generated a Node refetch query.
+fragment RefetchableFragmentFoo on RefetchableInterfaceFoo
+  @refetchable(queryName: "RefetchableFragmentFooQuery") {
+  id
+}
+
+
+# %extensions%
+
+interface RefetchableInterfaceFoo @fetchable(field_name: "id") {
+    id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterfaceFoo(id: ID!): RefetchableInterfaceFoo
+}

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface-some-types-impl-node.expected

@@ -0,0 +1,52 @@
+==================================== INPUT ====================================
+fragment RefetchableFragment on RefetchableInterface
+  @refetchable(queryName: "RefetchableFragmentQuery") {
+  id
+}
+
+# %extensions%
+
+interface RefetchableInterface @fetchable(field_name: "id") {
+    id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterface(id: ID!): RefetchableInterface
+}
+
+type ConcreteTypeImplementingRefetchableInterface implements RefetchableInterface & Node {
+  id: ID!
+}
+
+type ConcreteType2ImplementingRefetchableInterface implements RefetchableInterface {
+  id: ID!
+}
+==================================== OUTPUT ===================================
+query RefetchableFragmentQuery(
+  $id: ID!
+) @__RefetchableDerivedFromMetadata
+# RefetchableDerivedFromMetadata(
+#     FragmentDefinitionName(
+#         "RefetchableFragment",
+#     ),
+# )
+ {
+  fetch__RefetchableInterface(id: $id) {
+    ...RefetchableFragment
+  }
+}
+
+fragment RefetchableFragment on RefetchableInterface @refetchable(queryName: "RefetchableFragmentQuery") @__RefetchableMetadata
+# RefetchableMetadata {
+#     operation_name: "RefetchableFragmentQuery",
+#     path: [
+#         "fetch__RefetchableInterface",
+#     ],
+#     identifier_field: Some(
+#         "id",
+#     ),
+# }
+ {
+  id
+  __token
+}

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface-some-types-impl-node.graphql

@@ -0,0 +1,23 @@
+fragment RefetchableFragment on RefetchableInterface
+  @refetchable(queryName: "RefetchableFragmentQuery") {
+  id
+}
+
+# %extensions%
+
+interface RefetchableInterface @fetchable(field_name: "id") {
+    id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterface(id: ID!): RefetchableInterface
+}
+
+type ConcreteTypeImplementingRefetchableInterface implements RefetchableInterface & Node {
+  id: ID!
+}
+
+type ConcreteType2ImplementingRefetchableInterface implements RefetchableInterface {
+  id: ID!
+}
+

compiler/crates/relay-transforms/tests/refetchable_fragment/fixtures/refetchable-interface.expected

@@ -0,0 +1,92 @@
+==================================== INPUT ====================================
+fragment RefetchableFragment on RefetchableInterface
+  @refetchable(queryName: "RefetchableFragmentQuery") {
+  id
+}
+
+fragment RefetchableFragment2 on RefetchableInterface2
+  @refetchable(queryName: "RefetchableFragmentQuery2") {
+  __typename
+}
+
+# %extensions%
+
+interface RefetchableInterface @fetchable(field_name: "id") {
+    id: ID!
+}
+
+interface RefetchableInterface2 @fetchable(field_name: "not_id") {
+    not_id: ID!
+}
+
+extend type Query {
+  fetch__RefetchableInterface(id: ID!): RefetchableInterface
+  fetch__RefetchableInterface2(id: ID!): RefetchableInterface2
+}
+
+type ConcreteTypeImplementingRefetchableInterface implements RefetchableInterface {
+  id: ID!
+}
+
+type ConcreteTypeImplementingRefetchableInterface2 implements RefetchableInterface2 {
+  not_id: ID!
+}
+==================================== OUTPUT ===================================
+query RefetchableFragmentQuery(
+  $id: ID!
+) @__RefetchableDerivedFromMetadata
+# RefetchableDerivedFromMetadata(
+#     FragmentDefinitionName(
+#         "RefetchableFragment",
+#     ),
+# )
+ {
+  fetch__RefetchableInterface(id: $id) {
+    ...RefetchableFragment
+  }
+}
+
+query RefetchableFragmentQuery2(
+  $id: ID!
+) @__RefetchableDerivedFromMetadata
+# RefetchableDerivedFromMetadata(
+#     FragmentDefinitionName(
+#         "RefetchableFragment2",
+#     ),
+# )
+ {
+  fetch__RefetchableInterface2(id: $id) {
+    ...RefetchableFragment2
+  }
+}
+
+fragment RefetchableFragment on RefetchableInterface @refetchable(queryName: "RefetchableFragmentQuery") @__RefetchableMetadata
+# RefetchableMetadata {
+#     operation_name: "RefetchableFragmentQuery",
+#     path: [
+#         "fetch__RefetchableInterface",
+#     ],
+#     identifier_field: Some(
+#         "id",
+#     ),
+# }
+ {
+  id
+  __token
+}
+
+fragment RefetchableFragment2 on RefetchableInterface2 @refetchable(queryName: "RefetchableFragmentQuery2") @__RefetchableMetadata
+# RefetchableMetadata {
+#     operation_name: "RefetchableFragmentQuery2",
+#     path: [
+#         "fetch__RefetchableInterface2",
+#     ],
+#     identifier_field: Some(
+#         "not_id",
+#     ),
+# }
+ {
+  __typename
+  not_id
+  __token
+}