Add configuration skipInitialPoll to allow the SDK to be configured without any CDN requests. (FF-2047) (#60)

Author: leoromanovsky

src/client/eppo-client.ts

@@ -108,6 +108,7 @@ export type FlagConfigurationRequestParameters = {
   pollAfterSuccessfulInitialization?: boolean;
   pollAfterFailedInitialization?: boolean;
   throwOnFailedInitialization?: boolean;
+  skipInitialPoll?: boolean;
 };
 
 export default class EppoClient implements IEppoClient {
@@ -181,6 +182,7 @@ export default class EppoClient implements IEppoClient {
           this.configurationRequestParameters.pollAfterFailedInitialization ?? false,
         errorOnFailedStart:
           this.configurationRequestParameters.throwOnFailedInitialization ?? false,
+        skipInitialPoll: this.configurationRequestParameters.skipInitialPoll ?? false,
       },
     );
 

src/poller.spec.ts

@@ -22,6 +22,12 @@ describe('poller', () => {
   });
 
   describe('initial startup', () => {
+    it('skips initial poll if configured to do so', async () => {
+      const poller = initPoller(testIntervalMs, noOpCallback, { skipInitialPoll: true });
+      await poller.start();
+      td.verify(noOpCallback(), { times: 0 });
+    });
+
     it('retries startup poll within same promise', async () => {
       const pollerRetries = 3;
       let callCount = 0;

src/poller.ts

@@ -23,6 +23,7 @@ export default function initPoller(
     pollAfterSuccessfulStart?: boolean;
     errorOnFailedStart?: boolean;
     pollAfterFailedStart?: boolean;
+    skipInitialPoll?: boolean;
   },
 ): IPoller {
   let stopped = false;
@@ -34,8 +35,9 @@ export default function initPoller(
   const start = async () => {
     stopped = false;
     let startRequestSuccess = false;
-    let startAttemptsRemaining =
-      1 + (options?.maxStartRetries ?? DEFAULT_INITIAL_CONFIG_REQUEST_RETRIES);
+    let startAttemptsRemaining = options?.skipInitialPoll
+      ? 0
+      : 1 + (options?.maxStartRetries ?? DEFAULT_INITIAL_CONFIG_REQUEST_RETRIES);
 
     let startErrorToThrow = null;