fix: small bug and UT

reorgdetector/reorgdetector.go

@@ -134,7 +134,7 @@ func (bm blockMap) removeRange(from, to uint64) {
 type Subscription struct {
 	FirstReorgedBlock          chan uint64
 	ReorgProcessed             chan bool
-	pendingReorgsToBeProcessed *sync.WaitGroup
+	pendingReorgsToBeProcessed sync.WaitGroup
 }
 
 type ReorgDetector struct {
@@ -266,7 +266,7 @@ func (r *ReorgDetector) cleanStoredSubsBeforeStart(ctx context.Context, latestFi
 		sortedBlocks := blocks.getSorted()
 		lastTrackedBlock = sortedBlocks[len(blocks)-1].Num
 
-		for _, block = range blocks {
+		for _, block = range sortedBlocks {
 			if actualBlockHash, ok = blocksGotten[block.Num]; !ok {
 				actualBlock, err := r.ethClient.HeaderByNumber(ctx, big.NewInt(int64(block.Num)))
 				if err != nil {

reorgdetector/reorgdetector_test.go

@@ -84,6 +84,7 @@ func TestBlockMap(t *testing.T) {
 		t.Errorf("getFromBlockSorted() returned incorrect result, expected: %v, got: %v", expectedFromBlockSorted, fromBlockSorted)
 	}
 }
+
 func TestReorgDetector_New(t *testing.T) {
 	t.Parallel()
 
@@ -192,6 +193,50 @@ func TestReorgDetector_New(t *testing.T) {
 		require.True(t, exists)
 		require.Len(t, testSubscriberMap, 0) // since all blocks are finalized
 	})
+
+	t.Run("have tracked blocks and subscriptions - reorg happened", func(t *testing.T) {
+		t.Parallel()
+
+		client := NewEthClientMock(t)
+		db := newTestDB(t)
+
+		trackedBlocks := createTestBlocks(t, 1, 5)
+		testSubscriberBlocks := trackedBlocks[:5]
+
+		insertTestData(t, ctx, db, nil, unfalisedBlocksID) // no unfinalised blocks
+		insertTestData(t, ctx, db, testSubscriberBlocks, testSubscriber)
+
+		for _, block := range trackedBlocks[:3] {
+			client.On("HeaderByNumber", ctx, block.Number).Return(
+				block, nil,
+			)
+		}
+
+		reorgedBlocks := createTestBlocks(t, 4, 2)            // block 4, and 5 are reorged
+		reorgedBlocks[0].ParentHash = trackedBlocks[2].Hash() // block 4 is reorged but his parent is block 3
+		reorgedBlocks[1].ParentHash = reorgedBlocks[0].Hash() // block 5 is reorged but his parent is block 4
+
+		client.On("HeaderByNumber", ctx, reorgedBlocks[0].Number).Return(
+			reorgedBlocks[0], nil,
+		)
+
+		client.On("HeaderByNumber", ctx, big.NewInt(int64(rpc.FinalizedBlockNumber))).Return(
+			reorgedBlocks[len(reorgedBlocks)-1], nil,
+		)
+
+		rd, err := newReorgDetector(ctx, client, db)
+		require.NoError(t, err)
+		require.Len(t, rd.trackedBlocks, 2) // testSubscriber and unfinalisedBlocks
+
+		// we wait for the subscriber to be notified about the reorg
+		firstReorgedBlock := <-rd.subscriptions[testSubscriber].FirstReorgedBlock
+		require.Equal(t, reorgedBlocks[0].Number.Uint64(), firstReorgedBlock)
+
+		// all blocks should be cleaned from the tracked blocks
+		// since subscriber had 5 blocks, 3 were finalized, and 2 were reorged but also finalized
+		subscriberBlocks := rd.trackedBlocks[testSubscriber]
+		require.Len(t, subscriberBlocks, 0)
+	})
 }
 
 func createTestBlocks(t *testing.T, startBlock uint64, count uint64) []*types.Header {