[FFL-648] allowed pollAfterSuccessfulInitialization to be configurable (#111)

* feat: make pollAfterSuccessfulInitialization configurable

* test: add tests for pollAfterSuccessfulInitialization config

* chore: bump minor version

Author: sameerank

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/node-server-sdk",
-  "version": "3.11.0",
+  "version": "3.12.0",
   "description": "Eppo node server SDK",
   "main": "dist/index.js",
   "files": [

src/i-client-config.ts

@@ -43,6 +43,12 @@ export interface IClientConfig {
   /** Poll for new configurations even if the initial configuration request failed. (default: false) */
   pollAfterFailedInitialization?: boolean;
 
+  /**
+   * Poll for new configurations (every `pollingIntervalMs`) after successfully requesting the initial configuration. (default: true)
+   * For server-side applications, this defaults to true to ensure configurations stay up-to-date for the life of the process.
+   */
+  pollAfterSuccessfulInitialization?: boolean;
+
   /** Amount of time in milliseconds to wait between API calls to refresh configuration data. Default of 30_000 (30s). */
   pollingIntervalMs?: number;
 

src/index.spec.ts

@@ -708,4 +708,31 @@ describe('EppoClient E2E test', () => {
       });
     });
   });
+
+  describe('pollAfterSuccessfulInitialization', () => {
+    it('should default to true when not specified', async () => {
+      const client = await init({
+        apiKey,
+        baseUrl: `http://127.0.0.1:${TEST_SERVER_PORT}`,
+        assignmentLogger: mockLogger,
+      });
+      
+      // Access the internal configurationRequestParameters to verify the default
+      const configurationRequestParameters = client['configurationRequestParameters'];
+      expect(configurationRequestParameters.pollAfterSuccessfulInitialization).toBe(true);
+    });
+
+    it('should use the provided value when specified', async () => {
+      const client = await init({
+        apiKey,
+        baseUrl: `http://127.0.0.1:${TEST_SERVER_PORT}`,
+        assignmentLogger: mockLogger,
+        pollAfterSuccessfulInitialization: false,
+      });
+      
+      // Access the internal configurationRequestParameters to verify the custom value
+      const configurationRequestParameters = client['configurationRequestParameters'];
+      expect(configurationRequestParameters.pollAfterSuccessfulInitialization).toBe(false);
+    });
+  });
 });

src/index.ts

@@ -79,8 +79,8 @@ export async function init(config: IClientConfig): Promise<EppoClient> {
     requestTimeoutMs,
     numInitialRequestRetries,
     numPollRequestRetries,
-    // For server-side, we always want to keep polling for the life of the process
-    pollAfterSuccessfulInitialization: true,
+    // For server-side, we default to keep polling for the life of the process
+    pollAfterSuccessfulInitialization: config.pollAfterSuccessfulInitialization ?? true,
     pollAfterFailedInitialization,
     pollingIntervalMs,
     throwOnFailedInitialization,