fix(graphql): nextPage and prevPage are non nullable even though they can be null sometimes

packages/graphql/src/schema/buildPaginatedListType.ts

@@ -10,11 +10,11 @@ export const buildPaginatedListType = (name, docType) =>
       hasNextPage: { type: new GraphQLNonNull(GraphQLBoolean) },
       hasPrevPage: { type: new GraphQLNonNull(GraphQLBoolean) },
       limit: { type: new GraphQLNonNull(GraphQLInt) },
-      nextPage: { type: new GraphQLNonNull(GraphQLInt) },
+      nextPage: { type: GraphQLInt },
       offset: { type: GraphQLInt },
       page: { type: new GraphQLNonNull(GraphQLInt) },
       pagingCounter: { type: new GraphQLNonNull(GraphQLInt) },
-      prevPage: { type: new GraphQLNonNull(GraphQLInt) },
+      prevPage: { type: GraphQLInt },
       totalDocs: { type: new GraphQLNonNull(GraphQLInt) },
       totalPages: { type: new GraphQLNonNull(GraphQLInt) },
     },

test/graphql/int.spec.ts

@@ -104,5 +104,50 @@ describe('graphql', () => {
 
       expect(res.hyphenated_name).toStrictEqual('example-hyphenated-name')
     })
+
+    it('should not error because of non nullable fields', async () => {
+      await payload.delete({ collection: 'posts', where: {} })
+
+      // this is an array if any errors
+      const res_1 = await restClient
+        .GRAPHQL_POST({
+          body: JSON.stringify({
+            query: `
+query {
+  Posts {
+    docs {
+      title
+    }
+    prevPage
+  }
+}
+        `,
+          }),
+        })
+        .then((res) => res.json())
+      expect(res_1.errors).toBeFalsy()
+
+      await payload.create({
+        collection: 'posts',
+        data: { title: 'any-title' },
+      })
+
+      const res_2 = await restClient
+        .GRAPHQL_POST({
+          body: JSON.stringify({
+            query: `
+query {
+  Posts(limit: 1) {
+    docs {
+      title
+    }
+  }
+}
+        `,
+          }),
+        })
+        .then((res) => res.json())
+      expect(res_2.errors).toBeFalsy()
+    })
   })
 })