fix(common): manual impl Default for FeatureFlags to align FeatureFlags::default() with Serde per-field default

compiler/crates/common/src/feature_flags.rs

@@ -19,7 +19,7 @@ use serde::Serialize;
 use crate::Rollout;
 use crate::rollout::RolloutRange;
 
-#[derive(Default, Debug, Serialize, Deserialize, Clone, JsonSchema)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, JsonSchema)]
 #[serde(deny_unknown_fields)]
 pub struct FeatureFlags {
     #[serde(default)]
@@ -181,7 +181,51 @@ pub struct FeatureFlags {
     pub legacy_include_path_in_required_reader_nodes: FeatureFlag,
 }
 
-#[derive(Debug, serde::Deserialize, Clone, Serialize, Default, JsonSchema)]
+impl Default for FeatureFlags {
+    fn default() -> Self {
+        FeatureFlags {
+            relay_resolver_enable_interface_output_type: Default::default(),
+            allow_output_type_resolvers: Default::default(),
+            no_inline: Default::default(),
+            enable_3d_branch_arg_generation: Default::default(),
+            actor_change_support: Default::default(),
+            text_artifacts: Default::default(),
+            skip_printing_nulls: Default::default(),
+            compact_query_text: Default::default(),
+            enable_resolver_normalization_ast: Default::default(),
+            enable_exec_time_resolvers_directive: Default::default(),
+            enable_relay_resolver_mutations: Default::default(),
+            enable_strict_custom_scalars: Default::default(),
+            allow_resolvers_in_mutation_response: Default::default(),
+            allow_required_in_mutation_response: Default::default(),
+            disable_resolver_reader_ast: Default::default(),
+            enable_fragment_argument_transform: Default::default(),
+            allow_resolver_non_nullable_return_type: Default::default(),
+            disable_schema_validation: Default::default(),
+            prefer_fetchable_in_refetch_queries: Default::default(),
+            disable_edge_type_name_validation_on_declerative_connection_directives:
+                Default::default(),
+            disable_full_argument_type_validation: Default::default(),
+            use_reader_module_imports: Default::default(),
+            omit_resolver_type_assertions_for_confirmed_types: Default::default(),
+            disable_deduping_common_structures_in_artifacts: Default::default(),
+            legacy_include_path_in_required_reader_nodes: Default::default(),
+
+            // enabled-by-default
+            enforce_fragment_alias_where_ambiguous: FeatureFlag::Enabled,
+        }
+    }
+}
+
+#[derive(
+    Debug,
+    serde::Deserialize,
+    Clone,
+    Serialize,
+    Default,
+    PartialEq,
+    JsonSchema
+)]
 #[serde(tag = "kind", rename_all = "lowercase")]
 pub enum FeatureFlag {
     /// Fully disabled: developers may not use this feature
@@ -237,3 +281,27 @@ impl Display for FeatureFlag {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn default_trait_sets_enforce_fragment_alias_enabled() {
+        let flags = FeatureFlags::default();
+        assert!(matches!(
+            flags.enforce_fragment_alias_where_ambiguous,
+            FeatureFlag::Enabled
+        ));
+        // A couple of quick sanity checks for other defaults
+        assert!(matches!(flags.no_inline, FeatureFlag::Disabled));
+        assert_eq!(flags.enable_resolver_normalization_ast, false);
+    }
+
+    #[test]
+    fn serde_empty_object_deserializes_to_default() {
+        // When deserializing from an empty JSON object, serde applies per-field defaults.
+        let flags: FeatureFlags = serde_json::from_str("{} ").expect("valid json");
+        assert_eq!(flags, FeatureFlags::default());
+    }
+}

compiler/crates/common/src/rollout.rs

@@ -14,7 +14,16 @@ use serde::Serialize;
 /// A utility to enable gradual rollout of large codegen changes.
 /// Can be constructed as the Default which passes or a percentage between 0 and
 /// 100.
-#[derive(Default, Debug, Serialize, Deserialize, Clone, Copy, JsonSchema)]
+#[derive(
+    Default,
+    Debug,
+    Serialize,
+    Deserialize,
+    Clone,
+    Copy,
+    PartialEq,
+    JsonSchema
+)]
 pub struct Rollout(pub Option<u8>);
 
 impl Rollout {
@@ -34,7 +43,7 @@ impl Rollout {
 
 /// A utility to enable gradual rollout of large codegen changes. Allows you to
 /// specify a range of percentages to rollout.
-#[derive(Debug, Serialize, Deserialize, Clone, Copy, JsonSchema)]
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq, JsonSchema)]
 pub struct RolloutRange {
     pub start: u8,
     pub end: u8,

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement-dont-flatten-type-discriminator-fragment-spread-conditional.expected

@@ -5,7 +5,7 @@ query abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditiona
       # Fragment will be inlined:
       #  - Printed query should select __isNode
       #  - Normalization ast should include inline fragment with abstractKey
-      ...abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditional_NodeFragment
+      ...abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditional_NodeFragment @alias
     }
   }
 }
@@ -47,8 +47,19 @@ fragment abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditi
             "passingValue": true,
             "selections": [
               {
-                "args": null,
-                "kind": "FragmentSpread",
+                "fragment": {
+                  "kind": "InlineFragment",
+                  "selections": [
+                    {
+                      "args": null,
+                      "kind": "FragmentSpread",
+                      "name": "abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditional_NodeFragment"
+                    }
+                  ],
+                  "type": "Node",
+                  "abstractKey": "__isNode"
+                },
+                "kind": "AliasedInlineFragmentSpread",
                 "name": "abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditional_NodeFragment"
               }
             ]

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement-dont-flatten-type-discriminator-fragment-spread-conditional.graphql

@@ -4,7 +4,7 @@ query abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditiona
       # Fragment will be inlined:
       #  - Printed query should select __isNode
       #  - Normalization ast should include inline fragment with abstractKey
-      ...abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditional_NodeFragment
+      ...abstractTypeRefinementDontFlattenTypeDiscriminatorFragmentSpreadConditional_NodeFragment @alias
     }
   }
 }

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement-dont-skip-type-discriminator-fragment-spread.expected

@@ -4,13 +4,13 @@ query abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_AbstractType
     # After inlining even though `id` will be skipped:
     #  - Printed query should still select __isNode and __isActor
     #  - Normalization ast should include inline fragments with abstractKeys for Node and Actor
-    ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment
+    ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment @alias
   }
 }
 
 fragment abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment on Actor {
   username
-  ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment
+  ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment @alias
 }
 
 fragment abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment on Node {
@@ -39,8 +39,19 @@ fragment abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragm
         "plural": false,
         "selections": [
           {
-            "args": null,
-            "kind": "FragmentSpread",
+            "fragment": {
+              "kind": "InlineFragment",
+              "selections": [
+                {
+                  "args": null,
+                  "kind": "FragmentSpread",
+                  "name": "abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment"
+                }
+              ],
+              "type": "Actor",
+              "abstractKey": "__isActor"
+            },
+            "kind": "AliasedInlineFragmentSpread",
             "name": "abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment"
           }
         ],
@@ -153,8 +164,19 @@ fragment abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragm
       "storageKey": null
     },
     {
-      "args": null,
-      "kind": "FragmentSpread",
+      "fragment": {
+        "kind": "InlineFragment",
+        "selections": [
+          {
+            "args": null,
+            "kind": "FragmentSpread",
+            "name": "abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment"
+          }
+        ],
+        "type": "Node",
+        "abstractKey": "__isNode"
+      },
+      "kind": "AliasedInlineFragmentSpread",
       "name": "abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment"
     }
   ],

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement-dont-skip-type-discriminator-fragment-spread.graphql

@@ -3,13 +3,13 @@ query abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_AbstractType
     # After inlining even though `id` will be skipped:
     #  - Printed query should still select __isNode and __isActor
     #  - Normalization ast should include inline fragments with abstractKeys for Node and Actor
-    ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment
+    ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment @alias
   }
 }
 
 fragment abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_ActorFragment on Actor {
   username
-  ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment
+  ...abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment @alias
 }
 
 fragment abstractTypeRefinementDontSkipTypeDiscriminatorFragmentSpread_NodeFragment on Node {

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement-dont-skip-type-discriminator-inline-fragment.expected

@@ -4,7 +4,7 @@ query abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_AbstractType
     # After inlining even though `id` will be skipped:
     #  - Printed query should still select __isNode and __isActor
     #  - Normalization ast should include inline fragments with abstractKeys for Node and Actor
-    ...abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFragment
+    ...abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFragment @alias
   }
 }
 
@@ -37,8 +37,19 @@ fragment abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFrag
         "plural": false,
         "selections": [
           {
-            "args": null,
-            "kind": "FragmentSpread",
+            "fragment": {
+              "kind": "InlineFragment",
+              "selections": [
+                {
+                  "args": null,
+                  "kind": "FragmentSpread",
+                  "name": "abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFragment"
+                }
+              ],
+              "type": "Actor",
+              "abstractKey": "__isActor"
+            },
+            "kind": "AliasedInlineFragmentSpread",
             "name": "abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFragment"
           }
         ],

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement-dont-skip-type-discriminator-inline-fragment.graphql

@@ -3,7 +3,7 @@ query abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_AbstractType
     # After inlining even though `id` will be skipped:
     #  - Printed query should still select __isNode and __isActor
     #  - Normalization ast should include inline fragments with abstractKeys for Node and Actor
-    ...abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFragment
+    ...abstractTypeRefinementDontSkipTypeDiscriminatorInlineFragment_ActorFragment @alias
   }
 }
 

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement.expected

@@ -4,7 +4,7 @@ query abstractTypeRefinement_AbstractTypeRefinementQuery {
     ... on Named {
       name_from_query: name
     }
-    ...abstractTypeRefinement_ActorFragment
+    ...abstractTypeRefinement_ActorFragment @alias
   }
 }
 
@@ -51,8 +51,19 @@ fragment abstractTypeRefinement_ActorFragment on Actor {
             "abstractKey": "__isNamed"
           },
           {
-            "args": null,
-            "kind": "FragmentSpread",
+            "fragment": {
+              "kind": "InlineFragment",
+              "selections": [
+                {
+                  "args": null,
+                  "kind": "FragmentSpread",
+                  "name": "abstractTypeRefinement_ActorFragment"
+                }
+              ],
+              "type": "Actor",
+              "abstractKey": "__isActor"
+            },
+            "kind": "AliasedInlineFragmentSpread",
             "name": "abstractTypeRefinement_ActorFragment"
           }
         ],

compiler/crates/relay-compiler/tests/compile_relay_artifacts/fixtures/abstract-type-refinement.graphql

@@ -3,7 +3,7 @@ query abstractTypeRefinement_AbstractTypeRefinementQuery {
     ... on Named {
       name_from_query: name
     }
-    ...abstractTypeRefinement_ActorFragment
+    ...abstractTypeRefinement_ActorFragment @alias
   }
 }