Default to keep-alive agents in Node environments for better performance

src/lib/contentstack-core.ts

@@ -4,15 +4,26 @@ import axios, { AxiosRequestHeaders, getAdapter } from 'axios';
 import { AxiosInstance, HttpClientParams } from './types';
 import { ERROR_MESSAGES } from './error-messages';
 
+const isNodeEnvironment = typeof window === 'undefined';
+
+// Guarded require: keeps 'http'/'https' out of browser bundles, which have no browser field of their own to redirect this.
+function createKeepAliveAgent(moduleName: 'http' | 'https') {
+  if (!isNodeEnvironment) {
+    return false as const;
+  }
+
+  return new (require(moduleName).Agent)({ keepAlive: true });
+}
+
 export function httpClient(options: HttpClientParams): AxiosInstance {
   const defaultConfig = {
     insecure: false,
     retryOnError: true,
     headers: {} as AxiosRequestHeaders,
     basePath: '',
     proxy: false as const,
-    httpAgent: false,
-    httpsAgent: false,
+    httpAgent: createKeepAliveAgent('http'),
+    httpsAgent: createKeepAliveAgent('https'),
     timeout: 30000,
     logHandler: (level: string, data?: any) => {
       if (level === 'error') {

test/contentstack-core.node-agent.spec.ts

@@ -0,0 +1,22 @@
+/**
+ * @jest-environment node
+ */
+import http from 'http';
+import https from 'https';
+import { httpClient } from '../src/lib/contentstack-core';
+
+describe('httpClient default connection agents (Node environment)', () => {
+  it('should default httpAgent to a keepAlive http.Agent when not explicitly provided', () => {
+    const instance = httpClient({});
+
+    expect(instance.defaults.httpAgent).toBeInstanceOf(http.Agent);
+    expect((instance.defaults.httpAgent as any).keepAlive).toBe(true);
+  });
+
+  it('should default httpsAgent to a keepAlive https.Agent when not explicitly provided', () => {
+    const instance = httpClient({});
+
+    expect(instance.defaults.httpsAgent).toBeInstanceOf(https.Agent);
+    expect((instance.defaults.httpsAgent as any).keepAlive).toBe(true);
+  });
+});

test/contentstack-core.spec.ts

@@ -77,6 +77,29 @@ describe('contentstackCore', () => {
     });
   });
 
+  describe('connection agents', () => {
+    it.each(['httpAgent', 'httpsAgent'])(
+      'should preserve an explicitly provided %s instead of defaulting it',
+      (agentOption) => {
+        const customAgent = { custom: true };
+        const options = { [agentOption]: customAgent };
+
+        const instance = httpClient(options as any);
+
+        expect((instance.defaults as any)[agentOption]).toEqual(customAgent);
+      }
+    );
+
+    it.each(['httpAgent', 'httpsAgent'])('should default %s to false in a browser-like environment', (agentOption) => {
+      // This spec file runs under jsdom (see jest.preset.js), so `window` is
+      // already defined here - matching a real browser, unlike the Node-only
+      // agent behavior covered in contentstack-core.node-agent.spec.ts.
+      const instance = httpClient({});
+
+      expect((instance.defaults as any)[agentOption]).toBe(false);
+    });
+  });
+
   describe('config.headers', () => {
     it('should include apiKey in headers when provided', () => {
       const options = {