keep logic of removing empty fields in a single place for tech debt

eth/tracers/internal/tracetest/supply_test.go

@@ -67,6 +67,33 @@ type supplyInfo struct {
 
 func emptyBlockGenerationFunc(b *core.BlockGen) {}
 
+func TestSupplyOmittedFields(t *testing.T) {
+	var (
+		config = *params.MergedTestChainConfig
+		gspec  = &core.Genesis{
+			Config: &config,
+		}
+	)
+
+	gspec.Config.TerminalTotalDifficulty = big.NewInt(0)
+
+	out, _, err := testSupplyTracer(t, gspec, func(b *core.BlockGen) {
+		b.SetPoS()
+	})
+	if err != nil {
+		t.Fatalf("failed to test supply tracer: %v", err)
+	}
+
+	expected := supplyInfo{
+		Number:     0,
+		Hash:       common.HexToHash("0x52f276d96f0afaaf2c3cb358868bdc2779c4b0cb8de3e7e5302e247c0b66a703"),
+		ParentHash: common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000000"),
+	}
+	actual := out[expected.Number]
+
+	compareAsJSON(t, expected, actual)
+}
+
 func TestSupplyGenesisAlloc(t *testing.T) {
 	var (
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")

eth/tracers/live/supply.go

@@ -112,10 +112,13 @@ func newSupply(cfg json.RawMessage) (*tracing.Hooks, error) {
 func newSupplyInfo() supplyInfo {
 	return supplyInfo{
 		Issuance: &supplyInfoIssuance{
+			GenesisAlloc: big.NewInt(0),
 			Reward:       big.NewInt(0),
 			Withdrawals:  big.NewInt(0),
 		},
 		Burn: &supplyInfoBurn{
+			EIP1559: big.NewInt(0),
+			Blob:    big.NewInt(0),
 			Misc:    big.NewInt(0),
 		},
 
@@ -139,10 +142,8 @@ func (s *supply) OnBlockStart(ev tracing.BlockEvent) {
 	// Calculate Burn for this block
 	if ev.Block.BaseFee() != nil {
 		burn := new(big.Int).Mul(new(big.Int).SetUint64(ev.Block.GasUsed()), ev.Block.BaseFee())
-		if burn.Sign() != 0 {
 		s.delta.Burn.EIP1559 = burn
 	}
-	}
 	// Blob burnt gas
 	if blobGas := ev.Block.BlobGasUsed(); blobGas != nil && *blobGas > 0 && ev.Block.ExcessBlobGas() != nil {
 		var (
@@ -165,8 +166,6 @@ func (s *supply) OnGenesisBlock(b *types.Block, alloc types.GenesisAlloc) {
 	s.delta.Hash = b.Hash()
 	s.delta.ParentHash = b.ParentHash()
 
-	s.delta.Issuance.GenesisAlloc = big.NewInt(0)
-
 	// Initialize supply with total allocation in genesis block
 	for _, account := range alloc {
 		s.delta.Issuance.GenesisAlloc.Add(s.delta.Issuance.GenesisAlloc, account.Balance)
@@ -269,6 +268,10 @@ func (s *supply) write(data any) {
 	}
 
 	// Remove empty fields
+	if supply.Issuance.GenesisAlloc.Sign() == 0 {
+		supply.Issuance.GenesisAlloc = nil
+	}
+
 	if supply.Issuance.Reward.Sign() == 0 {
 		supply.Issuance.Reward = nil
 	}
@@ -281,6 +284,14 @@ func (s *supply) write(data any) {
 		supply.Issuance = nil
 	}
 
+	if supply.Burn.EIP1559.Sign() == 0 {
+		supply.Burn.EIP1559 = nil
+	}
+
+	if supply.Burn.Blob.Sign() == 0 {
+		supply.Burn.Blob = nil
+	}
+
 	if supply.Burn.Misc.Sign() == 0 {
 		supply.Burn.Misc = nil
 	}