feat(graphql): allow to pass count: true to a join query (#13351)

Fixes https://github.com/payloadcms/payload/issues/13077

docs/fields/join.mdx

@@ -296,11 +296,16 @@ query {
         sort: "createdAt"
         limit: 5
         where: { author: { equals: "66e3431a3f23e684075aaeb9" } }
+        """
+        Optionally pass count: true if you want to retrieve totalDocs
+        """
+        count: true -- s
       ) {
         docs {
           title
         }
         hasNextPage
+        totalDocs
       }
     }
   }

packages/graphql/src/schema/fieldToSchemaMap.ts

@@ -379,9 +379,11 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
             ),
           },
           hasNextPage: { type: new GraphQLNonNull(GraphQLBoolean) },
+          totalDocs: { type: GraphQLInt },
         },
       }),
       args: {
+        count: { type: GraphQLBoolean },
         limit: {
           type: GraphQLInt,
         },
@@ -402,7 +404,7 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
       },
       async resolve(parent, args, context: Context) {
         const { collection } = field
-        const { limit, page, sort, where } = args
+        const { count = false, limit, page, sort, where } = args
         const { req } = context
 
         const draft = Boolean(args.draft ?? context.req.query?.draft)
@@ -429,7 +431,7 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
           throw new Error('GraphQL with array of join.field.collection is not implemented')
         }
 
-        const { docs } = await req.payload.find({
+        const { docs, totalDocs } = await req.payload.find({
           collection,
           depth: 0,
           draft,
@@ -439,7 +441,7 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
           locale: req.locale,
           overrideAccess: false,
           page,
-          pagination: false,
+          pagination: count ? true : false,
           req,
           sort,
           where: fullWhere,
@@ -454,6 +456,7 @@ export const fieldToSchemaMap: FieldToSchemaMap = {
         return {
           docs: shouldSlice ? docs.slice(0, -1) : docs,
           hasNextPage: limit === 0 ? false : limit < docs.length,
+          ...(count ? { totalDocs } : {}),
         }
       },
     }

test/joins/int.spec.ts

@@ -969,6 +969,37 @@ describe('Joins Field', () => {
       expect(unlimited.data.Categories.docs[0].relatedPosts.hasNextPage).toStrictEqual(false)
     })
 
+    it('should return totalDocs with count: true', async () => {
+      const queryWithLimit = `query {
+    Categories(where: {
+            name: { equals: "paginate example" }
+          }) {
+          docs {
+            relatedPosts(
+              sort: "createdAt",
+              limit: 4,
+              count: true
+            ) {
+              docs {
+                title
+              }
+              hasNextPage
+              totalDocs
+            }
+          }
+        }
+      }`
+      const pageWithLimit = await restClient
+        .GRAPHQL_POST({ body: JSON.stringify({ query: queryWithLimit }) })
+        .then((res) => res.json())
+      expect(pageWithLimit.data.Categories.docs[0].relatedPosts.docs).toHaveLength(4)
+      expect(pageWithLimit.data.Categories.docs[0].relatedPosts.docs[0].title).toStrictEqual(
+        'test 0',
+      )
+      expect(pageWithLimit.data.Categories.docs[0].relatedPosts.hasNextPage).toStrictEqual(true)
+      expect(pageWithLimit.data.Categories.docs[0].relatedPosts.totalDocs).toStrictEqual(15)
+    })
+
     it('should have simple paginate with page for joins', async () => {
       let queryWithLimit = `query {
     Categories(where: {