maint(ct): clean up GPO tests (#2494)

Cleans up OVM_GasPriceOracle tests using the same techniques as other
test cleanup PRs.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

packages/contracts/test/contracts/L2/predeploys/OVM_GasPriceOracle.spec.ts

-/* External Imports */
 import { ethers } from 'hardhat'
-import { ContractFactory, Contract, Signer } from 'ethers'
+import { Contract } from 'ethers'
 import { calculateL1GasUsed, calculateL1Fee } from '@eth-optimism/core-utils'
+import { SignerWithAddress } from '@nomiclabs/hardhat-ethers/signers'
 
 import { expect } from '../../../setup'
+import { deploy } from '../../../helpers'
 
 describe('OVM_GasPriceOracle', () => {
   const initialGasPrice = 0
-  let signer1: Signer
-  let signer2: Signer
-  before(async () => {
-    ;[signer1, signer2] = await ethers.getSigners()
-  })
 
-  let Factory__OVM_GasPriceOracle: ContractFactory
+  let signer1: SignerWithAddress
+  let signer2: SignerWithAddress
   before(async () => {
-    Factory__OVM_GasPriceOracle = await ethers.getContractFactory(
-      'OVM_GasPriceOracle'
-    )
+    ;[signer1, signer2] = await ethers.getSigners()
   })
 
   let OVM_GasPriceOracle: Contract
   beforeEach(async () => {
-    OVM_GasPriceOracle = await Factory__OVM_GasPriceOracle.deploy(
-      await signer1.getAddress()
-    )
+    OVM_GasPriceOracle = await deploy('OVM_GasPriceOracle', {
+      signer: signer1,
+      args: [signer1.address],
+    })
 
     await OVM_GasPriceOracle.setOverhead(2750)
     await OVM_GasPriceOracle.setScalar(1500000)
@@ -33,9 +29,7 @@ describe('OVM_GasPriceOracle', () => {
 
   describe('owner', () => {
     it('should have an owner', async () => {
-      expect(await OVM_GasPriceOracle.owner()).to.equal(
-        await signer1.getAddress()
-      )
+      expect(await OVM_GasPriceOracle.owner()).to.equal(signer1.address)
     })
   })
 
@@ -46,12 +40,11 @@ describe('OVM_GasPriceOracle', () => {
     })
 
     it('should succeed if called by the owner and is equal to `0`', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setGasPrice(0)).to.not.be
-        .reverted
+      await expect(OVM_GasPriceOracle.setGasPrice(0)).to.not.be.reverted
     })
 
     it('should emit event', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setGasPrice(100))
+      await expect(OVM_GasPriceOracle.setGasPrice(100))
         .to.emit(OVM_GasPriceOracle, 'GasPriceUpdated')
         .withArgs(100)
     })
@@ -65,25 +58,18 @@ describe('OVM_GasPriceOracle', () => {
     it('should change when setGasPrice is called', async () => {
       const gasPrice = 1234
 
-      await OVM_GasPriceOracle.connect(signer1).setGasPrice(gasPrice)
+      await OVM_GasPriceOracle.setGasPrice(gasPrice)
 
       expect(await OVM_GasPriceOracle.gasPrice()).to.equal(gasPrice)
     })
 
     it('is the 1st storage slot', async () => {
-      const gasPrice = 333433
-      const slot = 1
+      await OVM_GasPriceOracle.setGasPrice(333433)
 
-      // set the price
-      await OVM_GasPriceOracle.connect(signer1).setGasPrice(gasPrice)
-
-      // get the storage slot value
-      const priceAtSlot = await signer1.provider.getStorageAt(
-        OVM_GasPriceOracle.address,
-        slot
-      )
       expect(await OVM_GasPriceOracle.gasPrice()).to.equal(
-        ethers.BigNumber.from(priceAtSlot)
+        ethers.BigNumber.from(
+          await signer1.provider.getStorageAt(OVM_GasPriceOracle.address, 1)
+        )
       )
     })
   })
@@ -95,12 +81,11 @@ describe('OVM_GasPriceOracle', () => {
     })
 
     it('should succeed if called by the owner', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setL1BaseFee(0)).to.not
-        .be.reverted
+      await expect(OVM_GasPriceOracle.setL1BaseFee(0)).to.not.be.reverted
     })
 
     it('should emit event', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setL1BaseFee(100))
+      await expect(OVM_GasPriceOracle.setL1BaseFee(100))
         .to.emit(OVM_GasPriceOracle, 'L1BaseFeeUpdated')
         .withArgs(100)
     })
@@ -113,24 +98,17 @@ describe('OVM_GasPriceOracle', () => {
 
     it('should change when setL1BaseFee is called', async () => {
       const baseFee = 1234
-      await OVM_GasPriceOracle.connect(signer1).setL1BaseFee(baseFee)
+      await OVM_GasPriceOracle.setL1BaseFee(baseFee)
       expect(await OVM_GasPriceOracle.l1BaseFee()).to.equal(baseFee)
     })
 
     it('is the 2nd storage slot', async () => {
-      const baseFee = 12345
-      const slot = 2
-
-      // set the price
-      await OVM_GasPriceOracle.connect(signer1).setGasPrice(baseFee)
+      await OVM_GasPriceOracle.setGasPrice(12345)
 
-      // get the storage slot value
-      const priceAtSlot = await signer1.provider.getStorageAt(
-        OVM_GasPriceOracle.address,
-        slot
-      )
       expect(await OVM_GasPriceOracle.l1BaseFee()).to.equal(
-        ethers.BigNumber.from(priceAtSlot)
+        ethers.BigNumber.from(
+          await signer1.provider.getStorageAt(OVM_GasPriceOracle.address, 2)
+        )
       )
     })
   })
@@ -150,9 +128,10 @@ describe('OVM_GasPriceOracle', () => {
     for (const input of inputs) {
       it(`case: ${input}`, async () => {
         const overhead = await OVM_GasPriceOracle.overhead()
-        const cost = await OVM_GasPriceOracle.getL1GasUsed(input)
-        const expected = calculateL1GasUsed(input, overhead)
-        expect(cost).to.deep.equal(expected)
+
+        expect(await OVM_GasPriceOracle.getL1GasUsed(input)).to.deep.equal(
+          calculateL1GasUsed(input, overhead)
+        )
       })
     }
   })
@@ -162,19 +141,16 @@ describe('OVM_GasPriceOracle', () => {
       it(`case: ${input}`, async () => {
         await OVM_GasPriceOracle.setGasPrice(1)
         await OVM_GasPriceOracle.setL1BaseFee(1)
-        const decimals = await OVM_GasPriceOracle.decimals()
-        const overhead = await OVM_GasPriceOracle.overhead()
-        const scalar = await OVM_GasPriceOracle.scalar()
-        const l1BaseFee = await OVM_GasPriceOracle.l1BaseFee()
-        const l1Fee = await OVM_GasPriceOracle.getL1Fee(input)
-        const expected = calculateL1Fee(
-          input,
-          overhead,
-          l1BaseFee,
-          scalar,
-          decimals
+
+        expect(await OVM_GasPriceOracle.getL1Fee(input)).to.deep.equal(
+          calculateL1Fee(
+            input,
+            await OVM_GasPriceOracle.overhead(),
+            await OVM_GasPriceOracle.l1BaseFee(),
+            await OVM_GasPriceOracle.scalar(),
+            await OVM_GasPriceOracle.decimals()
+          )
         )
-        expect(l1Fee).to.deep.equal(expected)
       })
     }
   })
@@ -186,12 +162,11 @@ describe('OVM_GasPriceOracle', () => {
     })
 
     it('should succeed if called by the owner', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setOverhead(0)).to.not.be
-        .reverted
+      await expect(OVM_GasPriceOracle.setOverhead(0)).to.not.be.reverted
     })
 
     it('should emit event', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setOverhead(100))
+      await expect(OVM_GasPriceOracle.setOverhead(100))
         .to.emit(OVM_GasPriceOracle, 'OverheadUpdated')
         .withArgs(100)
     })
@@ -204,24 +179,17 @@ describe('OVM_GasPriceOracle', () => {
 
     it('should change when setOverhead is called', async () => {
       const overhead = 6657
-      await OVM_GasPriceOracle.connect(signer1).setOverhead(overhead)
+      await OVM_GasPriceOracle.setOverhead(overhead)
       expect(await OVM_GasPriceOracle.overhead()).to.equal(overhead)
     })
 
     it('is the 3rd storage slot', async () => {
-      const overhead = 119090
-      const slot = 3
+      await OVM_GasPriceOracle.setOverhead(119090)
 
-      // set the price
-      await OVM_GasPriceOracle.connect(signer1).setOverhead(overhead)
-
-      // get the storage slot value
-      const priceAtSlot = await signer1.provider.getStorageAt(
-        OVM_GasPriceOracle.address,
-        slot
-      )
       expect(await OVM_GasPriceOracle.overhead()).to.equal(
-        ethers.BigNumber.from(priceAtSlot)
+        ethers.BigNumber.from(
+          await signer1.provider.getStorageAt(OVM_GasPriceOracle.address, 3)
+        )
       )
     })
   })
@@ -233,12 +201,11 @@ describe('OVM_GasPriceOracle', () => {
     })
 
     it('should succeed if called by the owner', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setScalar(0)).to.not.be
-        .reverted
+      await expect(OVM_GasPriceOracle.setScalar(0)).to.not.be.reverted
     })
 
     it('should emit event', async () => {
-      await expect(OVM_GasPriceOracle.connect(signer1).setScalar(100))
+      await expect(OVM_GasPriceOracle.setScalar(100))
         .to.emit(OVM_GasPriceOracle, 'ScalarUpdated')
         .withArgs(100)
     })
@@ -251,39 +218,27 @@ describe('OVM_GasPriceOracle', () => {
 
     it('should change when setScalar is called', async () => {
       const scalar = 9999
-      await OVM_GasPriceOracle.connect(signer1).setScalar(scalar)
+      await OVM_GasPriceOracle.setScalar(scalar)
       expect(await OVM_GasPriceOracle.scalar()).to.equal(scalar)
     })
 
     it('is the 4rd storage slot', async () => {
-      const overhead = 111111
-      const slot = 4
-
-      // set the price
-      await OVM_GasPriceOracle.connect(signer1).setScalar(overhead)
+      await OVM_GasPriceOracle.setScalar(111111)
 
-      // get the storage slot value
-      const priceAtSlot = await signer1.provider.getStorageAt(
-        OVM_GasPriceOracle.address,
-        slot
-      )
       expect(await OVM_GasPriceOracle.scalar()).to.equal(
-        ethers.BigNumber.from(priceAtSlot)
+        ethers.BigNumber.from(
+          await signer1.provider.getStorageAt(OVM_GasPriceOracle.address, 4)
+        )
       )
     })
   })
 
   describe('decimals', () => {
     it('is the 5th storage slot', async () => {
-      const slot = 5
-
-      // get the storage slot value
-      const priceAtSlot = await signer1.provider.getStorageAt(
-        OVM_GasPriceOracle.address,
-        slot
-      )
       expect(await OVM_GasPriceOracle.decimals()).to.equal(
-        ethers.BigNumber.from(priceAtSlot)
+        ethers.BigNumber.from(
+          await signer1.provider.getStorageAt(OVM_GasPriceOracle.address, 5)
+        )
       )
     })
   })