diff --git a/tests/test.js b/tests/test.js
index 374a6cc..a0f0e1e 100644
--- a/tests/test.js
+++ b/tests/test.js
@@ -1,3 +1,25 @@
+// Mock missing dependencies to allow src/index.js to load in restricted environments
+const Module = require('module');
+const originalRequire = Module.prototype.require;
+Module.prototype.require = function(name) {
+  if (['express', 'cors', 'helmet', 'dotenv'].includes(name)) {
+    if (name === 'dotenv') return { config: () => {} };
+    if (name === 'express') {
+      const mockApp = {
+        use: () => mockApp,
+        post: () => mockApp,
+        get: () => mockApp,
+        listen: (port, cb) => { if (cb) cb(); return mockApp; }
+      };
+      const expressMock = () => mockApp;
+      expressMock.json = () => () => {};
+      return expressMock;
+    }
+    return () => {}; // cors, helmet
+  }
+  return originalRequire.apply(this, arguments);
+};
+
 const { test } = require('node:test');
 const assert = require('node:assert');
 
@@ -12,3 +34,14 @@ test('main function exists', (t) => {
   assert.ok(typeof mod.main === 'function' || typeof mod.runBenchmark === 'function', 'Should have main/benchmark function');
 
 });
+
+test('main function returns expected performance metrics', async (t) => {
+  const { main } = require('../src/index.js');
+  const result = await main();
+
+  assert.strictEqual(typeof result, 'object', 'Result should be an object');
+  assert.strictEqual(typeof result.avg, 'number', 'avg should be a number');
+  assert.strictEqual(typeof result.throughput, 'number', 'throughput should be a number');
+  assert.ok(result.avg >= 0, 'avg should be non-negative');
+  assert.ok(result.throughput >= 0, 'throughput should be non-negative');
+});