core-utils: ethers l2 context receipt

Have the ethers L2 context helper pass through the
new optimistic ethereum related fields

.changeset/four-chairs-press.md

+---
+'@eth-optimism/core-utils': minor
+---
+
+Parse optimistic ethereum specific fields on transaction receipts

l2geth/rollup/fees/rollup_fee.go

@@ -9,7 +9,6 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rollup/rcfg"
@@ -159,7 +158,6 @@ func CalculateL1GasUsed(data []byte, overhead *big.Int) *big.Int {
 func DeriveL1GasInfo(msg Message, state StateDB) (*big.Int, *big.Int, *big.Int, *big.Float, error) {
 	tx := asTransaction(msg)
 	raw, err := rlpEncode(tx)
-	fmt.Println(hexutil.Encode(raw))
 	if err != nil {
 		return nil, nil, nil, nil, err
 	}

packages/core-utils/src/l2context.ts

 import cloneDeep from 'lodash/cloneDeep'
-import { providers } from 'ethers'
+import { providers, BigNumber } from 'ethers'
 
 const parseNumber = (n: string | number): number => {
   if (typeof n === 'string' && n.startsWith('0x')) {
@@ -69,5 +69,17 @@ export const injectL2Context = (l1Provider: providers.JsonRpcProvider) => {
     return tx
   }
 
+  const formatReceiptResponse = provider.formatter.receipt.bind(
+    provider.formatter
+  )
+  provider.formatter.receipt = (receipt) => {
+    const r = formatReceiptResponse(receipt)
+    r.l1GasPrice = BigNumber.from(receipt.l1GasPrice)
+    r.l1GasUsed = BigNumber.from(receipt.l1GasUsed)
+    r.l1Fee = BigNumber.from(receipt.l1Fee)
+    r.l1FeeScalar = parseFloat(receipt.l1FeeScalar)
+    return r
+  }
+
   return provider
 }