fix: retry full synchronization after polling errors

packages/neuron-wallet/src/block-sync-renderer/sync/full-synchronizer.ts

@@ -30,12 +30,16 @@ export default class FullSynchronizer extends Synchronizer {
       await this.processNextBlockNumber()
 
       while (this.pollingIndexer) {
-        const indexerTipBlock = await this.indexer.tip()
-        await this.synchronize(indexerTipBlock)
+        try {
+          const indexerTipBlock = await this.indexer.tip()
+          await this.synchronize(indexerTipBlock)
+        } catch (error) {
+          logger.error(`Full synchronization iteration failed; retrying in 5 seconds: ${error.message}`)
+        }
         await CommonUtils.sleep(5000)
       }
     } catch (error) {
-      logger.error(`Error connecting to Indexer: ${error.message}`)
+      logger.error(`Failed to initialize full synchronization: ${error.message}`)
     }
   }
 

packages/neuron-wallet/tests/block-sync-renderer/full-synchronizer.test.ts

@@ -338,11 +338,14 @@ describe('unit tests for IndexerConnector', () => {
             await connectIndexer(indexerConnector)
             await flushPromises()
           })
-          it('throws error', async () => {
+          it('logs the queue worker error', () => {
             expect(stubbedLoggerErrorFn).toHaveBeenCalledWith(
               'Connector: \tError in processing next block number queue: Error: exception'
             )
           })
+          it('starts polling after the queue worker error', () => {
+            expect(stubbedTipFn).toHaveBeenCalledTimes(1)
+          })
         })
       })
       describe('#blockTipsSubject', () => {
@@ -399,6 +402,46 @@ describe('unit tests for IndexerConnector', () => {
           })
         })
       })
+      describe('when a polling iteration fails', () => {
+        const sqliteBusyError = new Error('SQLITE_BUSY: database is locked')
+        let tipObserver: any
+
+        beforeEach(async () => {
+          tipObserver = jest.fn()
+          indexerConnector.blockTipsSubject.subscribe(tip => {
+            tipObserver(tip)
+          })
+          stubbedTipFn.mockResolvedValue(fakeTip1)
+          stubbedUpsertTxHashesFn.mockRejectedValueOnce(sqliteBusyError).mockResolvedValue([])
+          stubbedNextUnprocessedTxsGroupedByBlockNumberFn.mockResolvedValue([])
+          stubbedNextUnprocessedBlock.mockResolvedValue(undefined)
+
+          await connectIndexer(indexerConnector)
+        })
+
+        it('logs the error without emitting a block tip', () => {
+          expect(stubbedLoggerErrorFn).toHaveBeenCalledWith(
+            'Full synchronization iteration failed; retrying in 5 seconds: SQLITE_BUSY: database is locked'
+          )
+          expect(tipObserver).toHaveBeenCalledTimes(0)
+        })
+
+        describe('after the polling interval', () => {
+          beforeEach(async () => {
+            jest.advanceTimersByTime(5000)
+            await flushPromises()
+          })
+
+          it('continues polling and emits the recovered block tip', () => {
+            expect(stubbedTipFn).toHaveBeenCalledTimes(2)
+            expect(tipObserver).toHaveBeenCalledTimes(1)
+            expect(tipObserver).toHaveBeenCalledWith({
+              cacheTipNumber: parseInt(fakeTip1.blockNumber),
+              indexerTipNumber: parseInt(fakeTip1.blockNumber),
+            })
+          })
+        })
+      })
     })
   })
 })