From 7ed3b19f781e7f27c8087a33e7276194b609c9ac Mon Sep 17 00:00:00 2001
From: Duckki Oe <duckki.oe@apollographql.com>
Date: Thu, 1 Aug 2024 18:58:01 -0700
Subject: [PATCH] fix(federation): fixed a mismatch after merging PR #5743

- FetchNode's `variable_usages` field incorrectly included the "representations" variable.
---
 .../src/query_plan/fetch_dependency_graph.rs   | 18 ++++++++----------
 .../handles_operations_with_directives.rs      |  3 +++
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/apollo-federation/src/query_plan/fetch_dependency_graph.rs b/apollo-federation/src/query_plan/fetch_dependency_graph.rs
index 9eb638def7..1b6bedb55b 100644
--- a/apollo-federation/src/query_plan/fetch_dependency_graph.rs
+++ b/apollo-federation/src/query_plan/fetch_dependency_graph.rs
@@ -2362,6 +2362,14 @@ impl FetchDependencyGraphNode {
                 .cloned()
                 .collect::<Vec<_>>()
         };
+        let variable_usages = {
+            let mut list = variable_definitions
+                .iter()
+                .map(|var_def| var_def.name.clone())
+                .collect::<Vec<_>>();
+            list.sort();
+            list
+        };
 
         let mut operation = if self.is_entity_fetch {
             operation_for_entities_fetch(
@@ -2387,16 +2395,6 @@ impl FetchDependencyGraphNode {
             operation.reuse_fragments(fragments)?;
         }
 
-        let variable_usages = {
-            let mut list = operation
-                .variables
-                .iter()
-                .map(|variable| variable.name.clone())
-                .collect::<Vec<_>>();
-            list.sort();
-            list
-        };
-
         let operation_document = operation.try_into()?;
 
         let node = super::PlanNode::Fetch(Box::new(super::FetchNode {
diff --git a/apollo-federation/tests/query_plan/build_query_plan_tests/handles_operations_with_directives.rs b/apollo-federation/tests/query_plan/build_query_plan_tests/handles_operations_with_directives.rs
index 7a79e150b2..23508b7d02 100644
--- a/apollo-federation/tests/query_plan/build_query_plan_tests/handles_operations_with_directives.rs
+++ b/apollo-federation/tests/query_plan/build_query_plan_tests/handles_operations_with_directives.rs
@@ -148,6 +148,9 @@ fn test_if_directives_at_the_operation_level_are_passed_down_to_subgraph_queries
         }
       }
     "#);
+    // This checks a regression where the `variable_usages` included the `representations` variable.
+    assert_eq!(b_fetch_nodes[0].variable_usages.len(), 0);
+    assert_eq!(b_fetch_nodes[1].variable_usages.len(), 0);
 }
 
 #[test]