Extend @exhaustive validation to interfaces

compiler/crates/relay-transforms/src/errors.rs

@@ -223,25 +223,27 @@ pub enum ValidationMessage {
     },
 
     #[error(
-        "Field '{field_name}' marked with @exhaustive is missing selection for union members: {member_names}."
+        "Field '{field_name}' marked with @exhaustive is missing selection for {type_description}: {member_names}."
     )]
-    MissingExhaustiveUnionMembersOnField {
+    MissingExhaustiveMembersOnField {
         field_name: StringKey,
         member_names: String,
+        type_description: &'static str,
     },
 
     #[error(
-        "Fragment '{fragment_name}' marked with @exhaustive is missing selection for union members: {member_names}."
+        "Fragment '{fragment_name}' marked with @exhaustive is missing selection for {type_description}: {member_names}."
     )]
-    MissingExhaustiveUnionMembersOnFragment {
+    MissingExhaustiveMembersOnFragment {
         fragment_name: StringKey,
         member_names: String,
+        type_description: &'static str,
     },
 
     #[error(
-        "The @exhaustive directive can only be applied to fields or fragment definitions returning union types."
+        "The @exhaustive directive can only be applied to fields or fragment definitions returning union or interface types."
     )]
-    ExhaustiveDirectiveOnNonUnionField,
+    ExhaustiveDirectiveOnNonUnionOrInterfaceField,
 }
 
 #[derive(

compiler/crates/relay-transforms/src/validations/validate_exhaustive_directive.rs

@@ -18,10 +18,12 @@ use intern::string_key::Intern;
 use intern::string_key::StringKey;
 use lazy_static::lazy_static;
 use relay_config::ProjectConfig;
+use schema::InterfaceID;
 use schema::ObjectID;
 use schema::SDLSchema;
 use schema::Schema;
 use schema::Type;
+use schema::UnionID;
 
 use crate::ValidationMessage;
 
@@ -93,9 +95,9 @@ impl<'schema, 'program, 'pc> ExhaustiveDirectiveValidator<'schema, 'program, 'pc
         (ignored, disabled)
     }
 
-    fn check_exhaustive_coverage(
+    fn check_exhaustive_union_coverage(
         &self,
-        union_id: schema::UnionID,
+        union_id: UnionID,
         ignored: &std::collections::HashSet<StringKey>,
         has_selection_fn: impl Fn(ObjectID) -> bool,
     ) -> Vec<StringKey> {
@@ -114,6 +116,37 @@ impl<'schema, 'program, 'pc> ExhaustiveDirectiveValidator<'schema, 'program, 'pc
         missing_members
     }
 
+    fn check_exhaustive_interface_coverage(
+        &self,
+        interface_id: InterfaceID,
+        ignored: &std::collections::HashSet<StringKey>,
+        has_selection_fn: impl Fn(ObjectID) -> bool,
+    ) -> Vec<StringKey> {
+        let mut implementing_objects = self
+            .schema
+            .interface(interface_id)
+            .recursively_implementing_objects(self.schema.as_ref())
+            .into_iter()
+            .collect::<Vec<_>>();
+        implementing_objects.sort_by_key(|object_id| {
+            self.schema.get_type_name(Type::Object(*object_id))
+        });
+
+        let mut missing_members = Vec::new();
+
+        for object_id in implementing_objects {
+            let member_name = self.schema.get_type_name(Type::Object(object_id));
+            if ignored.contains(&member_name) {
+                continue;
+            }
+            if !has_selection_fn(object_id) {
+                missing_members.push(member_name);
+            }
+        }
+
+        missing_members
+    }
+
     fn validate_exhaustive(&mut self, field: &LinkedField) {
         let mut ignored = std::collections::HashSet::new();
         let mut has_directive = false;
@@ -138,21 +171,28 @@ impl<'schema, 'program, 'pc> ExhaustiveDirectiveValidator<'schema, 'program, 'pc
 
         let field_def = self.schema.field(field.definition.item);
         let return_type = field_def.type_.inner();
-        let union_id = match return_type {
-            Type::Union(id) => id,
+        let (missing_members, type_description) = match return_type {
+            Type::Union(id) => (
+                self.check_exhaustive_union_coverage(id, &ignored, |object_id| {
+                    self.has_selection_for_object(field, object_id)
+                }),
+                "union members",
+            ),
+            Type::Interface(id) => (
+                self.check_exhaustive_interface_coverage(id, &ignored, |object_id| {
+                    self.has_selection_for_object(field, object_id)
+                }),
+                "interface implementations",
+            ),
             _ => {
                 self.errors.push(Diagnostic::error(
-                    ValidationMessage::ExhaustiveDirectiveOnNonUnionField,
+                    ValidationMessage::ExhaustiveDirectiveOnNonUnionOrInterfaceField,
                     field.definition.location,
                 ));
                 return;
             }
         };
 
-        let missing_members = self.check_exhaustive_coverage(union_id, &ignored, |object_id| {
-            self.has_selection_for_object(field, object_id)
-        });
-
         if !missing_members.is_empty() {
             let field_name = field.alias.map_or(field_def.name.item, |a| a.item);
             let member_names = missing_members
@@ -162,9 +202,10 @@ impl<'schema, 'program, 'pc> ExhaustiveDirectiveValidator<'schema, 'program, 'pc
                 .join(", ");
 
             self.errors.push(Diagnostic::error(
-                ValidationMessage::MissingExhaustiveUnionMembersOnField {
+                ValidationMessage::MissingExhaustiveMembersOnField {
                     field_name,
                     member_names,
+                    type_description,
                 },
                 field.definition.location,
             ));
@@ -182,21 +223,28 @@ impl<'schema, 'program, 'pc> ExhaustiveDirectiveValidator<'schema, 'program, 'pc
             return;
         }
 
-        let union_id = match fragment.type_condition {
-            Type::Union(id) => id,
+        let (missing_members, type_description) = match fragment.type_condition {
+            Type::Union(id) => (
+                self.check_exhaustive_union_coverage(id, &ignored, |object_id| {
+                    self.has_selection_for_object_in_fragment(fragment, object_id)
+                }),
+                "union members",
+            ),
+            Type::Interface(id) => (
+                self.check_exhaustive_interface_coverage(id, &ignored, |object_id| {
+                    self.has_selection_for_object_in_fragment(fragment, object_id)
+                }),
+                "interface implementations",
+            ),
             _ => {
                 self.errors.push(Diagnostic::error(
-                    ValidationMessage::ExhaustiveDirectiveOnNonUnionField,
+                    ValidationMessage::ExhaustiveDirectiveOnNonUnionOrInterfaceField,
                     fragment.name.location,
                 ));
                 return;
             }
         };
 
-        let missing_members = self.check_exhaustive_coverage(union_id, &ignored, |object_id| {
-            self.has_selection_for_object_in_fragment(fragment, object_id)
-        });
-
         if !missing_members.is_empty() {
             let fragment_name = fragment.name.item.into();
             let member_names = missing_members
@@ -206,9 +254,10 @@ impl<'schema, 'program, 'pc> ExhaustiveDirectiveValidator<'schema, 'program, 'pc
                 .join(", ");
 
             self.errors.push(Diagnostic::error(
-                ValidationMessage::MissingExhaustiveUnionMembersOnFragment {
+                ValidationMessage::MissingExhaustiveMembersOnFragment {
                     fragment_name,
                     member_names,
+                    type_description,
                 },
                 fragment.name.location,
             ));
@@ -295,7 +344,7 @@ impl Validator for ExhaustiveDirectiveValidator<'_, '_, '_> {
     fn validate_scalar_field(&mut self, field: &ScalarField) -> DiagnosticsResult<()> {
         if field.directives.named(*EXHAUSTIVE_DIRECTIVE_NAME).is_some() {
             self.errors.push(Diagnostic::error(
-                ValidationMessage::ExhaustiveDirectiveOnNonUnionField,
+                ValidationMessage::ExhaustiveDirectiveOnNonUnionOrInterfaceField,
                 field.definition.location,
             ));
         }

compiler/crates/relay-transforms/tests/validate_exhaustive_directive/fixtures/directive-on-non-union.invalid.expected

@@ -4,7 +4,7 @@ fragment DirectiveOnNonUnion on User {
   name @exhaustive
 }
 ==================================== ERROR ====================================
-✖︎ The @exhaustive directive can only be applied to fields or fragment definitions returning union types.
+✖︎ The @exhaustive directive can only be applied to fields or fragment definitions returning union or interface types.
 
   directive-on-non-union.invalid.graphql:3:3
     2 │ fragment DirectiveOnNonUnion on User {

compiler/crates/relay-transforms/tests/validate_exhaustive_directive/fixtures/interface-all-members-valid.expected

@@ -0,0 +1,34 @@
+==================================== INPUT ====================================
+fragment InterfaceAllMembersValid on User {
+  nameRenderable @exhaustive {
+    ... on PlainUserNameRenderer {
+      __typename
+    }
+    ... on MarkdownUserNameRenderer {
+      __typename
+    }
+    ... on ImplementsImplementsUserNameRenderable {
+      __typename
+    }
+    ... on ImplementsImplementsUserNameRenderableAndUserNameRenderable {
+      __typename
+    }
+  }
+}
+==================================== OUTPUT ===================================
+fragment InterfaceAllMembersValid on User {
+  nameRenderable @exhaustive {
+    ... on PlainUserNameRenderer {
+      __typename
+    }
+    ... on MarkdownUserNameRenderer {
+      __typename
+    }
+    ... on ImplementsImplementsUserNameRenderable {
+      __typename
+    }
+    ... on ImplementsImplementsUserNameRenderableAndUserNameRenderable {
+      __typename
+    }
+  }
+}

compiler/crates/relay-transforms/tests/validate_exhaustive_directive/fixtures/interface-all-members-valid.graphql

@@ -0,0 +1,16 @@
+fragment InterfaceAllMembersValid on User {
+  nameRenderable @exhaustive {
+    ... on PlainUserNameRenderer {
+      __typename
+    }
+    ... on MarkdownUserNameRenderer {
+      __typename
+    }
+    ... on ImplementsImplementsUserNameRenderable {
+      __typename
+    }
+    ... on ImplementsImplementsUserNameRenderableAndUserNameRenderable {
+      __typename
+    }
+  }
+}

compiler/crates/relay-transforms/tests/validate_exhaustive_directive/fixtures/interface-missing-member.invalid.expected

@@ -0,0 +1,17 @@
+==================================== INPUT ====================================
+#expected-to-throw
+fragment InterfaceMissingMember on User {
+  nameRenderable @exhaustive {
+    ... on PlainUserNameRenderer { __typename }
+    ... on MarkdownUserNameRenderer { __typename }
+    ... on ImplementsImplementsUserNameRenderable { __typename }
+  }
+}
+==================================== ERROR ====================================
+✖︎ Field 'nameRenderable' marked with @exhaustive is missing selection for interface implementations: 'ImplementsImplementsUserNameRenderableAndUserNameRenderable'.
+
+  interface-missing-member.invalid.graphql:3:3
+    2 │ fragment InterfaceMissingMember on User {
+    3 │   nameRenderable @exhaustive {
+      │   ^^^^^^^^^^^^^^
+    4 │     ... on PlainUserNameRenderer { __typename }

compiler/crates/relay-transforms/tests/validate_exhaustive_directive/fixtures/interface-missing-member.invalid.graphql

@@ -0,0 +1,7 @@
+fragment InterfaceMissingMember on User {
+  nameRenderable @exhaustive {
+    ... on PlainUserNameRenderer { __typename }
+    ... on MarkdownUserNameRenderer { __typename }
+    ... on ImplementsImplementsUserNameRenderable { __typename }
+  }
+}

compiler/crates/relay-transforms/tests/validate_exhaustive_directive_test.rs

@@ -169,3 +169,41 @@ async fn multiple_missing_members() {
     )
     .await;
 }
+
+#[tokio::test]
+async fn interface_all_members_valid() {
+    let input = include_str!(
+        "validate_exhaustive_directive/fixtures/interface-all-members-valid.graphql"
+    );
+    let expected = include_str!(
+        "validate_exhaustive_directive/fixtures/interface-all-members-valid.expected"
+    );
+    test_fixture(
+        transform_fixture,
+        file!(),
+        "interface-all-members-valid.graphql",
+        "validate_exhaustive_directive/fixtures/interface-all-members-valid.expected",
+        input,
+        expected,
+    )
+    .await;
+}
+
+#[tokio::test]
+async fn interface_missing_member() {
+    let input = include_str!(
+        "validate_exhaustive_directive/fixtures/interface-missing-member.invalid.graphql"
+    );
+    let expected = include_str!(
+        "validate_exhaustive_directive/fixtures/interface-missing-member.invalid.expected"
+    );
+    test_fixture(
+        transform_fixture,
+        file!(),
+        "interface-missing-member.invalid.graphql",
+        "validate_exhaustive_directive/fixtures/interface-missing-member.invalid.expected",
+        input,
+        expected,
+    )
+    .await;
+}