Fix issue with path in query plan's deferred nodes

internals-js/src/operations.ts

@@ -441,6 +441,12 @@ export type OperationElement = Field<any> | FragmentElement;
 
 export type OperationPath = OperationElement[];
 
+export function operationPathToStringPath(path: OperationPath): string[] {
+  return path
+    .filter((p) => !(p.kind === 'FragmentElement' && !p.typeCondition))
+    .map((p) => p.kind === 'Field' ? p.responseName() : `... on ${p.typeCondition?.coordinate}`);
+}
+
 export function sameOperationPaths(p1: OperationPath, p2: OperationPath): boolean {
   if (p1 === p2) {
     return true;

query-planner-js/src/QueryPlan.ts

@@ -93,8 +93,9 @@ export interface DeferredNode {
   }[],
   // The optional defer label.
   label?: string,
-  // Path to the @defer this correspond to. The `subselection` starts at that `path`.
-  path: ResponsePath,
+  // Path, in the query, to the @defer this corresponds to. The `subselection` starts at that `queryPath`.
+  // This look like: `[ 'products', '... on Book', 'reviews' ]`
+  queryPath: string[],
   // The part of the original query that "selects" the data to send in that deferred response (once the plan in `node` completes). Will be set _unless_ `node` is a `DeferNode` itself.
   subselection?: string,
   // The plan to get all the data for that deferred part. Usually set, but can be undefined for a `@defer` where everything has been fetched in the "primary block", that is when

query-planner-js/src/__tests__/buildPlan.defer.test.ts

@@ -243,7 +243,7 @@ describe('non-router-based-defer', () => {
               },
             }
           }, [
-            Deferred(depends: [], path: "t.v") {
+            Deferred(depends: [], path: "t/v") {
               {
                 b
               }:
@@ -444,7 +444,7 @@ describe('non-router-based-defer', () => {
               },
             }
           }, [
-            Deferred(depends: [0], path: "t.v") {
+            Deferred(depends: [0], path: "t/v") {
               {
                 u {
                   x
@@ -838,7 +838,7 @@ test('multiple (non-nested) @defer + label handling', () => {
               },
             }
           },
-          Deferred(depends: [1], path: "t.v3", label: "defer_in_v3") {
+          Deferred(depends: [1], path: "t/v3", label: "defer_in_v3") {
             {
               y
             }:
@@ -990,7 +990,7 @@ describe('nested @defer', () => {
                     },
                   }
                 }, [
-                  Deferred(depends: [1], path: "me.messages.@.author") {
+                  Deferred(depends: [1], path: "me/messages/author") {
                     {
                       messages {
                         body
@@ -1114,7 +1114,7 @@ describe('nested @defer', () => {
                     },
                   }
                 }, [
-                  Deferred(depends: [], path: "me.messages.@") {
+                  Deferred(depends: [], path: "me/messages") {
                     {
                       body {
                         lines
@@ -2180,7 +2180,7 @@ test('@defer on query root type', () => {
             },
           }
         }, [
-          Deferred(depends: [0], path: "op2.next") {
+          Deferred(depends: [0], path: "op2/next") {
             {
               op1
               op4
@@ -2721,7 +2721,7 @@ describe('defer with conditions', () => {
                             },
                           }
                         }, [
-                          Deferred(depends: [1], path: "t.u") {
+                          Deferred(depends: [1], path: "t/u") {
                             {
                               b
                             }:
@@ -2812,7 +2812,7 @@ describe('defer with conditions', () => {
                         },
                       }
                     },
-                    Deferred(depends: [0], path: "t.u") {
+                    Deferred(depends: [0], path: "t/u") {
                       {
                         b
                       }:
@@ -3552,3 +3552,99 @@ test('@defer only the key of an entity', () => {
     }
   `);
 });
+
+test('the path in @defer includes traversed fragments', () => {
+  const subgraph1 = {
+    name: 'Subgraph1',
+    typeDefs: gql`
+      type Query {
+        i : I
+      }
+
+      interface I {
+        x: Int
+      }
+
+      type A implements I {
+        x: Int
+        t: T
+      }
+
+      type T @key(fields: "id") {
+        id: ID!
+        v1: String
+        v2: String
+      }
+    `
+  }
+
+  const [api, queryPlanner] = composeAndCreatePlannerWithDefer(subgraph1);
+  const operation = operationFromDocument(api, gql`
+    {
+      i {
+        ... on A {
+          t {
+            v1
+            ... @defer {
+              v2
+            }
+          }
+        }
+      }
+    }
+  `);
+
+  const plan = queryPlanner.buildQueryPlan(operation);
+  expect(plan).toMatchInlineSnapshot(`
+    QueryPlan {
+      Defer {
+        Primary {
+          {
+            i {
+              ... on A {
+                t {
+                  v1
+                }
+              }
+            }
+          }:
+          Fetch(service: "Subgraph1", id: 0) {
+            {
+              i {
+                __typename
+                ... on A {
+                  t {
+                    __typename
+                    v1
+                    id
+                  }
+                }
+              }
+            }
+          }
+        }, [
+          Deferred(depends: [0], path: "i/... on A/t") {
+            {
+              v2
+            }:
+            Flatten(path: "i.t") {
+              Fetch(service: "Subgraph1") {
+                {
+                  ... on T {
+                    __typename
+                    id
+                  }
+                } =>
+                {
+                  ... on T {
+                    v2
+                  }
+                }
+              },
+            }
+          },
+        ]
+      },
+    }
+  `);
+});