maint(ct): clean up library tests (#2513)

Cleans up tests for all Library contracts using same techniques as
previous PRs.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

packages/contracts/test/contracts/libraries/codec/Lib_OVMCodec.spec.ts

-/* External Imports */
-import { ethers } from 'hardhat'
 import { Contract } from 'ethers'
 
-/* Internal Imports */
 import { expect } from '../../../setup'
-import { NON_ZERO_ADDRESS } from '../../../helpers'
+import { NON_ZERO_ADDRESS, deploy } from '../../../helpers'
 
 describe('Lib_OVMCodec', () => {
   let Lib_OVMCodec: Contract
   before(async () => {
-    Lib_OVMCodec = await (
-      await ethers.getContractFactory('TestLib_OVMCodec')
-    ).deploy()
+    Lib_OVMCodec = await deploy('TestLib_OVMCodec')
   })
 
   describe('hashTransaction', () => {

packages/contracts/test/contracts/libraries/rlp/Lib_RLPReader.spec.ts

-/* Internal Imports */
 import { Lib_RLPReader_TEST_JSON } from '../../../data'
 import { runJsonTest } from '../../../helpers'
 

packages/contracts/test/contracts/libraries/rlp/Lib_RLPWriter.spec.ts

-/* External Imports */
-import { ethers } from 'hardhat'
 import { Contract } from 'ethers'
 
-/* Internal Imports */
 import { expect } from '../../../setup'
 import { Lib_RLPWriter_TEST_JSON } from '../../../data'
+import { deploy } from '../../../helpers'
 
 const encode = async (Lib_RLPWriter: Contract, input: any): Promise<void> => {
   if (Array.isArray(input)) {
-    const elements = await Promise.all(
+    return Lib_RLPWriter.writeList(
+      await Promise.all(
         input.map(async (el) => {
           return encode(Lib_RLPWriter, el)
         })
       )
-
-    return Lib_RLPWriter.writeList(elements)
+    )
   } else if (Number.isInteger(input)) {
     return Lib_RLPWriter.writeUint(input)
   } else {
@@ -25,9 +23,7 @@ const encode = async (Lib_RLPWriter: Contract, input: any): Promise<void> => {
 describe('Lib_RLPWriter', () => {
   let Lib_RLPWriter: Contract
   before(async () => {
-    Lib_RLPWriter = await (
-      await ethers.getContractFactory('TestLib_RLPWriter')
-    ).deploy()
+    Lib_RLPWriter = await deploy('TestLib_RLPWriter')
   })
 
   describe('Official Ethereum RLP Tests', () => {
@@ -50,14 +46,11 @@ describe('Lib_RLPWriter', () => {
 
   describe('Use of library with other memory-modifying operations', () => {
     it('should allow creation of a contract beforehand and still work', async () => {
-      const randomAddress = '0x1234123412341234123412341234123412341234'
-      const rlpEncodedRandomAddress =
-        '0x941234123412341234123412341234123412341234'
-      const encoded =
+      expect(
         await Lib_RLPWriter.callStatic.writeAddressWithTaintedMemory(
-          randomAddress
+          '0x1234123412341234123412341234123412341234'
         )
-      expect(encoded).to.eq(rlpEncodedRandomAddress)
+      ).to.eq('0x941234123412341234123412341234123412341234')
     })
   })
 })

packages/contracts/test/contracts/libraries/standards/AddressAliasHelper.spec.ts

-/* External Imports */
-import { ethers } from 'hardhat'
 import { Contract } from 'ethers'
 import { applyL1ToL2Alias, undoL1ToL2Alias } from '@eth-optimism/core-utils'
 
 import { expect } from '../../../setup'
+import { deploy } from '../../../helpers'
 
 describe('AddressAliasHelper', () => {
   let AddressAliasHelper: Contract
   before(async () => {
-    AddressAliasHelper = await (
-      await ethers.getContractFactory('TestLib_AddressAliasHelper')
-    ).deploy()
+    AddressAliasHelper = await deploy('TestLib_AddressAliasHelper')
   })
 
   describe('applyL1ToL2Alias', () => {

packages/contracts/test/contracts/libraries/trie/Lib_MerkleTrie.spec.ts

-/* External Imports */
 import * as rlp from 'rlp'
 import { ethers } from 'hardhat'
 import { Contract } from 'ethers'
 import { toHexString } from '@eth-optimism/core-utils'
 
-/* Internal Imports */
 import { expect } from '../../../setup'
-import { TrieTestGenerator } from '../../../helpers'
+import { deploy, TrieTestGenerator } from '../../../helpers'
 
 const NODE_COUNTS = [1, 2, 32, 128]
 
 describe('Lib_MerkleTrie', () => {
   let Lib_MerkleTrie: Contract
   before(async () => {
-    Lib_MerkleTrie = await (
-      await ethers.getContractFactory('TestLib_MerkleTrie')
-    ).deploy()
+    Lib_MerkleTrie = await deploy('TestLib_MerkleTrie')
   })
 
   // Eth-foundation tests: https://github.com/ethereum/tests/tree/develop/TrieTests

packages/contracts/test/contracts/libraries/trie/Lib_SecureMerkleTrie.spec.ts

-/* External Imports */
-import { ethers } from 'hardhat'
 import { Contract } from 'ethers'
 
-/* Internal Imports */
 import { expect } from '../../../setup'
-import { TrieTestGenerator } from '../../../helpers'
+import { deploy, TrieTestGenerator } from '../../../helpers'
 
 const NODE_COUNTS = [1, 2, 128]
 
 describe('Lib_SecureMerkleTrie', () => {
   let Lib_SecureMerkleTrie: Contract
   before(async () => {
-    Lib_SecureMerkleTrie = await (
-      await ethers.getContractFactory('TestLib_SecureMerkleTrie')
-    ).deploy()
+    Lib_SecureMerkleTrie = await deploy('TestLib_SecureMerkleTrie')
   })
 
   describe('verifyInclusionProof', () => {

packages/contracts/test/contracts/libraries/utils/Lib_Buffer.spec.ts

-import hre from 'hardhat'
 import { Contract, ethers } from 'ethers'
 
 import { expect } from '../../../setup'
+import { deploy } from '../../../helpers'
 
 describe('Lib_Buffer', () => {
   let Lib_Buffer: Contract
   beforeEach(async () => {
-    const Factory__Lib_Buffer = await hre.ethers.getContractFactory(
-      'TestLib_Buffer'
-    )
-    Lib_Buffer = await Factory__Lib_Buffer.deploy()
+    Lib_Buffer = await deploy('TestLib_Buffer')
   })
 
   describe('push(bytes32,bytes27)', () => {

packages/contracts/test/contracts/libraries/utils/Lib_Bytes32Utils.spec.ts

-/* Internal Imports */
 import { Lib_Bytes32Utils_TEST_JSON } from '../../../data'
 import { runJsonTest } from '../../../helpers'
 

packages/contracts/test/contracts/libraries/utils/Lib_BytesUtils.spec.ts

-/* Internal Imports */
-import { ethers } from 'hardhat'
 import { Contract } from 'ethers'
 
-/* External Imports */
-import { Lib_BytesUtils_TEST_JSON } from '../../../data'
-import { runJsonTest } from '../../../helpers'
 import { expect } from '../../../setup'
+import { Lib_BytesUtils_TEST_JSON } from '../../../data'
+import { deploy, runJsonTest } from '../../../helpers'
 
 describe('Lib_BytesUtils', () => {
   describe('JSON tests', () => {
@@ -15,18 +12,17 @@ describe('Lib_BytesUtils', () => {
   describe('Use of library with other memory-modifying operations', () => {
     let TestLib_BytesUtils: Contract
     before(async () => {
-      TestLib_BytesUtils = await (
-        await ethers.getContractFactory('TestLib_BytesUtils')
-      ).deploy()
+      TestLib_BytesUtils = await deploy('TestLib_BytesUtils')
     })
 
     it('should allow creation of a contract beforehand and still work', async () => {
-      const slice = await TestLib_BytesUtils.callStatic.sliceWithTaintedMemory(
+      expect(
+        await TestLib_BytesUtils.callStatic.sliceWithTaintedMemory(
           '0x123412341234',
           0,
           0
         )
-      expect(slice).to.eq('0x')
+      ).to.eq('0x')
     })
   })
 })

packages/contracts/test/contracts/libraries/utils/Lib_MerkleTree.spec.ts

-/* External Imports */
 import { ethers } from 'hardhat'
 import { Contract, BigNumber } from 'ethers'
 import { MerkleTree } from 'merkletreejs'
 import { fromHexString, toHexString } from '@eth-optimism/core-utils'
 import { smock, FakeContract } from '@defi-wonderland/smock'
 
-/* Internal Imports */
 import { expect } from '../../../setup'
-import { NON_NULL_BYTES32 } from '../../../helpers'
+import { deploy, NON_NULL_BYTES32 } from '../../../helpers'
 
 const NODE_COUNTS = [
   2, 3, 7, 9, 13, 63, 64, 123, 128, 129, 255, 1021, 1023, 1024,
 ]
 
-const hash = (el: Buffer | string): Buffer => {
-  return Buffer.from(ethers.utils.keccak256(el).slice(2), 'hex')
-}
-
-const fillDefaultHashes = (elements: string[]): string[] => {
+const makeMerkleTree = (elements: string[]): MerkleTree => {
   const filled: string[] = []
-
   for (let i = 0; i < Math.pow(2, Math.ceil(Math.log2(elements.length))); i++) {
     if (i < elements.length) {
       filled.push(elements[i])
@@ -28,17 +21,19 @@ const fillDefaultHashes = (elements: string[]): string[] => {
     }
   }
 
-  return filled
+  return new MerkleTree(
+    filled.map(fromHexString),
+    (el: Buffer | string): Buffer => {
+      return fromHexString(ethers.utils.keccak256(el))
+    }
+  )
 }
 
 describe('Lib_MerkleTree', () => {
   let Lib_MerkleTree: Contract
   let Fake__LibMerkleTree: FakeContract<Contract>
   before(async () => {
-    Lib_MerkleTree = await (
-      await ethers.getContractFactory('TestLib_MerkleTree')
-    ).deploy()
-
+    Lib_MerkleTree = await deploy('TestLib_MerkleTree')
     Fake__LibMerkleTree = await smock.fake('TestLib_MerkleTree')
   })
 
@@ -66,17 +61,13 @@ describe('Lib_MerkleTree', () => {
     describe('when more than one element is provided', () => {
       for (const size of NODE_COUNTS) {
         it(`should generate the correct root when ${size} elements are provided`, async () => {
-          const elements = [...Array(size)].map((_, i) => {
+          const tree = makeMerkleTree(
+            [...Array(size)].map((_, i) => {
               return ethers.utils.keccak256(BigNumber.from(i).toHexString())
             })
+          )
 
-          const bufs = fillDefaultHashes(elements).map((element) => {
-            return fromHexString(element)
-          })
-
-          const tree = new MerkleTree(bufs, hash)
-
-          expect(await Lib_MerkleTree.getMerkleRoot(bufs)).to.equal(
+          expect(await Lib_MerkleTree.getMerkleRoot(tree.getLeaves())).to.equal(
             toHexString(tree.getRoot())
           )
         })
@@ -116,24 +107,6 @@ describe('Lib_MerkleTree', () => {
       })
     })
 
-    describe('when total elements is zero', () => {
-      const totalLeaves = 0
-
-      it('should revert', async () => {
-        await expect(
-          Lib_MerkleTree.verify(
-            ethers.constants.HashZero,
-            ethers.constants.HashZero,
-            0,
-            [],
-            totalLeaves
-          )
-        ).to.be.revertedWith(
-          'Lib_MerkleTree: Total leaves must be greater than zero.'
-        )
-      })
-    })
-
     describe('when an index is out of bounds', () => {
       const totalLeaves = 1
       const index = 2
@@ -187,26 +160,24 @@ describe('Lib_MerkleTree', () => {
     describe('with valid proof for more than one element', () => {
       for (const size of NODE_COUNTS) {
         describe(`for a tree with ${size} total elements`, () => {
-          const elements = [...Array(size)].map((_, i) => {
+          const tree = makeMerkleTree(
+            [...Array(size)].map((_, i) => {
               return ethers.utils.keccak256(BigNumber.from(i).toHexString())
             })
-
-          const bufs = fillDefaultHashes(elements).map((element) => {
-            return fromHexString(element)
-          })
-
-          const tree = new MerkleTree(bufs, hash)
+          )
 
           for (let i = 0; i < size; i += Math.ceil(size / 8)) {
             it(`should verify a proof for the ${i}(th/st/rd, whatever) element`, async () => {
-              const proof = tree.getProof(bufs[i], i).map((element) => {
+              const proof = tree
+                .getProof(tree.getLeaves()[i], i)
+                .map((element) => {
                   return element.data
                 })
 
               expect(
                 await Lib_MerkleTree.verify(
                   tree.getRoot(),
-                  bufs[i],
+                  tree.getLeaves()[i],
                   i,
                   proof,
                   size