feat(data-connect): Align SQL Connect Stream Transport Exponential Backoff Parameters with Other Platform SDKs (#10221)

* udpate exponential backoff params to match other SDKs

* add changeset

* update changeset

* Apply reviewer suggestion

* yarn run format

---------

Co-authored-by: Hanzo Dev <[email protected]>

.changeset/early-jars-cry.md

@@ -0,0 +1,5 @@
+---
+'@firebase/data-connect': patch
+---
+
+Align SQL Connect Stream Transport exponential backoff parameters with other platform SDKs. No need for public release note.

packages/data-connect/src/network/stream/streamTransport.ts

@@ -54,13 +54,9 @@ const IDLE_CONNECTION_TIMEOUT_MS = 15 * 1000; // 15 seconds
 /** Initial reconnect delay in ms */
 const INITIAL_RECONNECT_DELAY_MS = 1000; // 1 second
 /** Max reconnect delay in ms */
-const MAX_RECONNECT_DELAY_MS = 30 * 1000; // 30 seconds
-/** Max random jitter to add to reconnect delay in ms */
-const MAX_RECONNECT_JITTER_MS = 0.5 * 1000; // 0.5 seconds
+const MAX_RECONNECT_DELAY_MS = 60 * 1000; // 60 seconds
 /** Factor to multiply delay by on failure */
-const RECONNECT_BACKOFF_FACTOR = 1.3;
-/** Max number of reconnection attempts before giving up */
-const MAX_RECONNECT_ATTEMPTS = 10;
+const RECONNECT_BACKOFF_FACTOR = 1.5;
 
 /**
  * A promise returned to the user when invoking an operation via {@linkcode AbstractDataConnectStreamTransport.invokeQuery | invokeQuery}
@@ -445,19 +441,13 @@ export abstract class AbstractDataConnectStreamTransport extends AbstractDataCon
     if (this.reconnectTimer) {
       return;
     }
-    if (this.reconnectAttempts++ >= MAX_RECONNECT_ATTEMPTS) {
-      const errorString =
-        'Stream disconnected and could not reconnect - max stream reconnection attempts reached.';
-      logError(errorString);
-      void this.cleanupAndTerminate(Code.OTHER, errorString);
-      return;
-    }
+    this.reconnectAttempts++;
     const delay = this.reconnectDelayMs;
     this.reconnectDelayMs = Math.min(
       this.reconnectDelayMs * RECONNECT_BACKOFF_FACTOR,
       MAX_RECONNECT_DELAY_MS
     );
-    const jitter = Math.random() * MAX_RECONNECT_JITTER_MS;
+    const jitter = (Math.random() - 0.5) * delay;
 
     this.reconnectTimer = setTimeout(() => {
       this.reconnectTimer = null;

packages/data-connect/test/unit/streamTransport.test.ts

@@ -22,7 +22,7 @@ import * as sinon from 'sinon';
 import sinonChai from 'sinon-chai';
 
 import { DataConnectOptions } from '../../src/api/DataConnect';
-import { Code } from '../../src/core/error';
+import { Code, DataConnectError } from '../../src/core/error';
 import { AuthTokenProvider } from '../../src/core/FirebaseAuthProvider';
 import * as logger from '../../src/logger';
 import {
@@ -1993,6 +1993,64 @@ describe('AbstractDataConnectStreamTransport', () => {
           delete (global as any).document;
         }
       });
+
+      it('should exponentially back off with 1.5 multiplier and [-0.5x, +0.5x] jitter capped at 60s', async () => {
+        ensureConnectionStub.rejects(
+          new DataConnectError(Code.OTHER, 'Connection failed')
+        );
+        const randomStub = sinon.stub(Math, 'random');
+        const observer = {
+          onData: sinon.spy(),
+          onDisconnect: sinon.spy(),
+          onError: sinon.spy()
+        };
+        transport.invokeSubscribe(observer, queryName1, variables1);
+
+        // Attempt 1: base delay 1000ms, random=0 -> jitter -500ms -> delay 500ms
+        randomStub.returns(0);
+        transport.onStreamClose(1006, 'Abnormal Closure');
+
+        await clock.tickAsync(499);
+        expect(ensureConnectionStub).to.not.have.been.called;
+
+        // Set random=1 before attempt 1 failure triggers startReconnectBackoff for attempt 2
+        // Attempt 2: base delay 1500ms, random=1 -> jitter +750ms -> delay 2250ms
+        randomStub.returns(1);
+        await clock.tickAsync(1);
+        expect(ensureConnectionStub).to.have.been.calledOnce;
+
+        await clock.tickAsync(2249);
+        expect(ensureConnectionStub).to.have.been.calledOnce;
+
+        // Set random=0.5 before attempt 2 failure triggers startReconnectBackoff for attempt 3
+        // Attempt 3: base delay 2250ms, random=0.5 -> jitter 0ms -> delay 2250ms
+        randomStub.returns(0.5);
+        await clock.tickAsync(1);
+        expect(ensureConnectionStub).to.have.been.calledTwice;
+
+        await clock.tickAsync(2250);
+        expect(ensureConnectionStub).to.have.been.calledThrice;
+      });
+
+      it('should attempt reconnection indefinitely without a max attempt limit', async () => {
+        ensureConnectionStub.rejects(
+          new DataConnectError(Code.OTHER, 'Connection failed')
+        );
+        const observer = {
+          onData: sinon.spy(),
+          onDisconnect: sinon.spy(),
+          onError: sinon.spy()
+        };
+        transport.invokeSubscribe(observer, queryName1, variables1);
+        transport.onStreamClose(1006, 'Abnormal Closure');
+
+        // Fast-forward past 15 reconnection attempts
+        for (let i = 0; i < 15; i++) {
+          await clock.tickAsync(65000);
+        }
+
+        expect(ensureConnectionStub.callCount).to.be.at.least(15);
+      });
     });
   });