maint(ct): clean up CTC gas tests (#2462)

Another test cleanup PR, this time targeting the CTC gas tests. I'm
going to keep doing this as separate PRs because:
1. These are simple changes
2. They *look* complicated because there are a lot of them

Putting these into different PRs means they'll be easier to review and
I'll have to do less shepherding over relatively minor PRs.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

packages/contracts/test/contracts/L1/rollup/CanonicalTransactionChain.gas.spec.ts

 /* External Imports */
 import { ethers } from 'hardhat'
-import { Signer, ContractFactory, Contract } from 'ethers'
+import { Signer, Contract } from 'ethers'
 import { smock, FakeContract } from '@defi-wonderland/smock'
 import {
   AppendSequencerBatchParams,
@@ -9,11 +9,10 @@ import {
   expectApprox,
 } from '@eth-optimism/core-utils'
 import { TransactionResponse } from '@ethersproject/abstract-provider'
-import { keccak256 } from 'ethers/lib/utils'
 
 /* Internal Imports */
 import {
-  makeAddressManager,
+  deploy,
   setProxyTarget,
   L2_GAS_DISCOUNT_DIVISOR,
   ENQUEUE_GAS_COST,
@@ -31,11 +30,11 @@ const appendSequencerBatch = async (
   CanonicalTransactionChain: Contract,
   batch: AppendSequencerBatchParams
 ): Promise<TransactionResponse> => {
-  const methodId = keccak256(Buffer.from('appendSequencerBatch()')).slice(2, 10)
-  const calldata = encodeAppendSequencerBatch(batch)
   return CanonicalTransactionChain.signer.sendTransaction({
     to: CanonicalTransactionChain.address,
-    data: '0x' + methodId + calldata,
+    data:
+      ethers.utils.id('appendSequencerBatch()').slice(0, 10) +
+      encodeAppendSequencerBatch(batch),
   })
 }
 
@@ -47,8 +46,10 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
 
   let AddressManager: Contract
   let Fake__StateCommitmentChain: FakeContract
-  before(async () => {
-    AddressManager = await makeAddressManager()
+  let CanonicalTransactionChain: Contract
+  beforeEach(async () => {
+    AddressManager = await deploy('Lib_AddressManager')
+
     await AddressManager.setAddress(
       'OVM_Sequencer',
       await sequencer.getAddress()
@@ -63,37 +64,20 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
       'StateCommitmentChain',
       Fake__StateCommitmentChain
     )
-  })
-
-  let Factory__CanonicalTransactionChain: ContractFactory
-  let Factory__ChainStorageContainer: ContractFactory
-  before(async () => {
-    Factory__CanonicalTransactionChain = await ethers.getContractFactory(
-      'CanonicalTransactionChain'
-    )
-
-    Factory__ChainStorageContainer = await ethers.getContractFactory(
-      'ChainStorageContainer'
-    )
-  })
 
-  let CanonicalTransactionChain: Contract
-  beforeEach(async () => {
-    CanonicalTransactionChain = await Factory__CanonicalTransactionChain.deploy(
-      AddressManager.address,
-      MAX_GAS_LIMIT,
-      L2_GAS_DISCOUNT_DIVISOR,
-      ENQUEUE_GAS_COST
-    )
+    CanonicalTransactionChain = await deploy('CanonicalTransactionChain', {
+      signer: sequencer,
+      args: [
+        AddressManager.address,
+        MAX_GAS_LIMIT,
+        L2_GAS_DISCOUNT_DIVISOR,
+        ENQUEUE_GAS_COST,
+      ],
+    })
 
-    const batches = await Factory__ChainStorageContainer.deploy(
-      AddressManager.address,
-      'CanonicalTransactionChain'
-    )
-    await Factory__ChainStorageContainer.deploy(
-      AddressManager.address,
-      'CanonicalTransactionChain'
-    )
+    const batches = await deploy('ChainStorageContainer', {
+      args: [AddressManager.address, 'CanonicalTransactionChain'],
+    })
 
     await AddressManager.setAddress(
       'ChainStorageContainer-CTC-batches',
@@ -107,12 +91,7 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
   })
 
   describe('appendSequencerBatch [ @skip-on-coverage ]', () => {
-    beforeEach(() => {
-      CanonicalTransactionChain = CanonicalTransactionChain.connect(sequencer)
-    })
-
     it('200 transactions in a single context', async () => {
-      console.log(`Benchmark: 200 transactions in a single context.`)
       const timestamp = (await getEthTime(ethers.provider)) - 100
       const blockNumber = await getNextBlockNumber(ethers.provider)
 
@@ -143,13 +122,12 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
       const receipt = await res.wait()
       const gasUsed = receipt.gasUsed.toNumber()
 
-      console.log('Benchmark complete.')
-
       console.log('Fixed calldata cost:', fixedCalldataCost)
       console.log(
         'Non-calldata overhead gas cost per transaction:',
         (gasUsed - fixedCalldataCost) / numTxs
       )
+
       expectApprox(gasUsed, 1_402_638, {
         absoluteUpperDeviation: 1000,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
@@ -159,7 +137,6 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
     }).timeout(10_000_000)
 
     it('200 transactions in 200 contexts', async () => {
-      console.log(`Benchmark: 200 transactions in 200 contexts.`)
       const timestamp = (await getEthTime(ethers.provider)) - 100
       const blockNumber = await getNextBlockNumber(ethers.provider)
 
@@ -190,13 +167,12 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
       const receipt = await res.wait()
       const gasUsed = receipt.gasUsed.toNumber()
 
-      console.log('Benchmark complete.')
-
       console.log('Fixed calldata cost:', fixedCalldataCost)
       console.log(
         'Non-calldata overhead gas cost per transaction:',
         (gasUsed - fixedCalldataCost) / numTxs
       )
+
       expectApprox(gasUsed, 1_619_781, {
         absoluteUpperDeviation: 1000,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
@@ -248,12 +224,12 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
       const gasUsed = receipt.gasUsed.toNumber()
 
       console.log('Benchmark complete.')
-
       console.log('Fixed calldata cost:', fixedCalldataCost)
       console.log(
         'Non-calldata overhead gas cost per transaction:',
         (gasUsed - fixedCalldataCost) / numTxs
       )
+
       expectApprox(gasUsed, 891_158, {
         absoluteUpperDeviation: 1000,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
@@ -264,13 +240,12 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
   })
 
   describe('enqueue [ @skip-on-coverage ]', () => {
-    let enqueueL2GasPrepaid
-    let data
+    const data = '0x' + '12'.repeat(1234)
+
+    let enqueueL2GasPrepaid: number
     beforeEach(async () => {
-      CanonicalTransactionChain = CanonicalTransactionChain.connect(sequencer)
       enqueueL2GasPrepaid =
         await CanonicalTransactionChain.enqueueL2GasPrepaid()
-      data = '0x' + '12'.repeat(1234)
     })
 
     it('cost to enqueue a transaction above the prepaid threshold', async () => {
@@ -281,11 +256,10 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
         l2GasLimit,
         data
       )
+
       const receipt = await res.wait()
       const gasUsed = receipt.gasUsed.toNumber()
 
-      console.log('Benchmark complete.')
-
       expectApprox(gasUsed, 196_687, {
         absoluteUpperDeviation: 500,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
@@ -302,11 +276,10 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain [ @skip-on-coverage ]', () =
         l2GasLimit,
         data
       )
+
       const receipt = await res.wait()
       const gasUsed = receipt.gasUsed.toNumber()
 
-      console.log('Benchmark complete.')
-
       expectApprox(gasUsed, 134_100, {
         absoluteUpperDeviation: 500,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your