Feat: Resolver

.gitignore

@@ -3,4 +3,4 @@ node_modules
 .vercel
 AGENTS.md
 CLAUDE.md
-.next
+.next 

pages/api/graphql.js

@@ -8,10 +8,10 @@ const pool = new Pool({
   ssl: {
     rejectUnauthorized: false,
   },
-  max: 1, // Batasi 1 koneksi per instance serverless
+  max: 1,
 });
 
-// 2. Definisi Schema GraphQL (typeDefs)
+// 2. Definisi Schema GraphQL
 const typeDefs = `#graphql
   type Category {
     id: ID!
@@ -37,7 +37,26 @@ const typeDefs = `#graphql
   }
 `;
 
-// 3. Definisi Resolver (Query + Nested Resolvers)
+// 3. Plugin Apollo untuk menyuntikkan log counter ke response extensions
+const metricsPlugin = {
+  async requestDidStart() {
+    return {
+      async willSendResponse({ response, contextValue }) {
+        if (response.body.kind === 'single') {
+          response.body.singleResult.extensions = {
+            ...response.body.singleResult.extensions,
+            nPlusOneMetrics: {
+              totalCalls: contextValue.metrics.categoryProductsCalls,
+              resolverLogs: contextValue.metrics.callLogs,
+            },
+          };
+        }
+      },
+    };
+  },
+};
+
+// 4. Definisi Resolver
 const resolvers = {
   Query: {
     categories: async () => {
@@ -65,7 +84,16 @@ const resolvers = {
 
   // Resolver Relasi Category -> Products (One-to-Many)
   Category: {
-    products: async (parent) => {
+    products: async (parent, _, contextValue) => {
+      // Increment counter di context request saat ini
+      contextValue.metrics.categoryProductsCalls += 1;
+      const currentCall = contextValue.metrics.categoryProductsCalls;
+
+      // Simpan log urutan pemanggilan ke array context
+      contextValue.metrics.callLogs.push(
+        `[resolver counter] Category.products dipanggil ${currentCall} kali (category_id=${parent.id})`
+      );
+
       const result = await pool.query(
         'SELECT id, title, price::float, category_id, created_by FROM products WHERE category_id = $1 ORDER BY id ASC',
         [parent.id]
@@ -84,17 +112,26 @@ const resolvers = {
   },
 };
 
-// 4. Inisialisasi Apollo Server
+// 5. Inisialisasi Apollo Server dengan Plugin
 const server = new ApolloServer({
   typeDefs,
   resolvers,
   introspection: true,
-  csrfPrevention: false, // Mematikan proteksi CSRF agar request dari browser Sandbox tidak dicegat
+  csrfPrevention: false,
+  plugins: [metricsPlugin],
 });
 
-const apolloHandler = startServerAndCreateNextHandler(server);
+// 6. Inisialisasi Handler dengan Context Per-Request
+const apolloHandler = startServerAndCreateNextHandler(server, {
+  context: async () => ({
+    metrics: {
+      categoryProductsCalls: 0,
+      callLogs: [],
+    },
+  }),
+});
 
-// 5. Handler CORS untuk Apollo Studio dan Embedded Sandbox
+// 7. Handler CORS dan Serverless Entrypoint
 module.exports = async function handler(req, res) {
   const allowedOrigins = new Set([
     'https://studio.apollographql.com',
@@ -113,11 +150,10 @@ module.exports = async function handler(req, res) {
     'Content-Type, Authorization, apollo-require-preflight, x-apollo-operation-name'
   );
 
-  // Respons langsung untuk preflight OPTIONS request
   if (req.method === 'OPTIONS') {
     res.status(200).end();
     return;
   }
 
   return apolloHandler(req, res);
-};
+};