fix(graphql): preserve hasMany relationship order in populated results

packages/graphql/src/schema/fieldToSchemaMap.ts

@@ -704,15 +704,15 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
 
               if (result) {
                 if (isRelatedToManyCollections) {
-                  results.push({
+                  results[i] = {
                     relationTo: collectionSlug,
                     value: {
                       ...result,
                       collection: collectionSlug,
                     },
-                  })
+                  }
                 } else {
-                  results.push(result)
+                  results[i] = result
                 }
               }
             }
@@ -725,7 +725,10 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
           }
 
           await Promise.all(resultPromises)
-          return results
+          // Assigned by index above so the populated order matches the stored
+          // order regardless of which dataloader promise settles first. Filter
+          // out holes left by skipped (invalid collection / missing) entries.
+          return results.filter((result) => result !== undefined)
         }
 
         let id = value
@@ -1123,15 +1126,15 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
 
               if (result) {
                 if (isRelatedToManyCollections) {
-                  results.push({
+                  results[i] = {
                     relationTo: collectionSlug,
                     value: {
                       ...result,
                       collection: collectionSlug,
                     },
-                  })
+                  }
                 } else {
-                  results.push(result)
+                  results[i] = result
                 }
               }
             }
@@ -1144,7 +1147,10 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
           }
 
           await Promise.all(resultPromises)
-          return results
+          // Assigned by index above so the populated order matches the stored
+          // order regardless of which dataloader promise settles first. Filter
+          // out holes left by skipped (invalid collection / missing) entries.
+          return results.filter((result) => result !== undefined)
         }
 
         let id = value

test/graphql/config.ts

@@ -32,6 +32,17 @@ export default buildConfigWithDefaults({
             complexity: 801,
           },
         },
+        {
+          type: 'relationship',
+          name: 'singleRelation',
+          relationTo: 'posts',
+        },
+        {
+          type: 'relationship',
+          name: 'manyRelations',
+          hasMany: true,
+          relationTo: 'posts',
+        },
         {
           name: 'contentBlockField',
           type: 'blocks',

test/graphql/int.spec.ts

@@ -268,5 +268,43 @@ query {
 
       expect(afterDelete.errors).toBeUndefined()
     })
+
+    it('should preserve hasMany relationship order when a single relationship to the same collection is queried first', async () => {
+      const postA = await payload.create({ collection: 'posts', data: { title: 'A' } })
+      const postB = await payload.create({ collection: 'posts', data: { title: 'B' } })
+      const postC = await payload.create({ collection: 'posts', data: { title: 'C' } })
+
+      const parent = await payload.create({
+        collection: 'posts',
+        data: {
+          title: 'parent',
+          manyRelations: [postA.id, postB.id, postC.id],
+          singleRelation: postA.id,
+        },
+      })
+
+      const query = `query {
+        Post(id: ${idToString(parent.id, payload)}) {
+          singleRelation {
+            title
+          }
+          manyRelations {
+            title
+          }
+        }
+      }`
+
+      const response = await restClient
+        .GRAPHQL_POST({ body: JSON.stringify({ query }) })
+        .then((res) => res.json())
+
+      expect(response.errors).toBeUndefined()
+      expect(response.data.Post.manyRelations.map((doc) => doc.title)).toStrictEqual(['A', 'B', 'C'])
+
+      await payload.delete({
+        collection: 'posts',
+        where: { id: { in: [parent.id, postA.id, postB.id, postC.id] } },
+      })
+    })
   })
 })