fix: early exit if there are no expand-by-levels in datanode AMM mark…

…et-depth calc

core/execution/amm/estimator_test.go

@@ -294,5 +294,4 @@ func TestEstimateBoundsOneSided(t *testing.T) {
 	assert.True(t, metrics.LiquidationPriceAtLower.IsZero())
 	assert.True(t, metrics.PositionSizeAtLower.IsZero())
 	assert.True(t, metrics.LossOnCommitmentAtLower.IsZero())
-
 }

datanode/service/market_depth_amm.go

@@ -233,8 +233,11 @@ func (m *MarketDepth) getReference(ctx context.Context, marketID string) (num.De
 }
 
 func (m *MarketDepth) expandByLevels(pool entities.AMMPool, levels []*level, priceFactor num.Decimal) ([]*types.Order, []bool, error) {
-	// get positions
+	if len(levels) == 0 {
+		return nil, nil, nil
+	}
 
+	// get position
 	pos, err := m.getAMMPosition(pool.MarketID.String(), pool.AmmPartyID.String())
 	if err != nil {
 		return nil, nil, err

datanode/service/market_depth_amm_test.go

@@ -472,6 +472,34 @@ func TestFairgroundAMM(t *testing.T) {
 	assert.Equal(t, "12956", mds.service.GetBestAskPrice(marketID).String())
 }
 
+func TestAMMDepthOutOfRange(t *testing.T) {
+	ctx := context.Background()
+
+	cfg := service.MarketDepthConfig{
+		AmmFullExpansionPercentage: 200,
+		AmmEstimatedStepPercentage: 0,
+		AmmMaxEstimatedSteps:       0,
+	}
+	mds := getServiceWithConfig(t, cfg)
+	defer mds.ctrl.Finish()
+
+	marketID := vgcrypto.RandomHash()
+
+	ensureLiveOrders(t, mds, marketID)
+	ensureDecimalPlaces(t, mds, 1, 1)
+
+	// set the mid-price to a value no where near the AMM's prices
+	mds.marketData.EXPECT().GetMarketDataByID(gomock.Any(), gomock.Any()).Times(1).Return(entities.MarketData{MidPrice: num.DecimalFromInt64(10)}, nil)
+
+	// data node is starting from network history, initialise market-depth based on whats aleady there
+	ensureAMMs(t, mds, marketID)
+	mds.service.Initialise(ctx)
+
+	assert.Equal(t, 0, int(mds.service.GetTotalAMMVolume(marketID)))
+	assert.Equal(t, 0, int(mds.service.GetAMMVolume(marketID, true)))
+	assert.Equal(t, 0, int(mds.service.GetAMMVolume(marketID, false)))
+}
+
 func ensureLiveOrders(t *testing.T, mds *MDS, marketID string) {
 	t.Helper()
 	mds.orders.EXPECT().GetLiveOrders(gomock.Any()).Return([]entities.Order{