integration-tests: Test a bridged token transfer too

integration-tests/test/bridged-tokens.ts

-import { BigNumber, Contract, ContractFactory } from 'ethers'
+import { BigNumber, Contract, ContractFactory, utils, Wallet } from 'ethers'
 import { ethers } from 'hardhat'
 import * as L2Artifact from '@eth-optimism/contracts/artifacts/contracts/standards/L2StandardERC20.sol/L2StandardERC20.json'
 import { expect } from 'chai'
 
 import { OptimismEnv } from './shared/env'
-import { isLiveNetwork, l1Wallet } from './shared/utils'
+import { isLiveNetwork } from './shared/utils'
 import { Direction } from './shared/watcher-utils'
 
 describe('Bridged tokens', () => {
   let env: OptimismEnv
 
+  let otherWalletL1: Wallet
+  let otherWalletL2: Wallet
+
   let L1Factory__ERC20: ContractFactory
   let L1__ERC20: Contract
   let L2Factory__ERC20: ContractFactory
@@ -18,6 +21,18 @@ describe('Bridged tokens', () => {
   before(async () => {
     env = await OptimismEnv.new()
 
+    const other = Wallet.createRandom()
+    otherWalletL1 = other.connect(env.l1Wallet.provider)
+    otherWalletL2 = other.connect(env.l2Wallet.provider)
+    await env.l1Wallet.sendTransaction({
+      to: otherWalletL1.address,
+      value: utils.parseEther('0.01'),
+    })
+    await env.l2Wallet.sendTransaction({
+      to: otherWalletL2.address,
+      value: utils.parseEther('0.01'),
+    })
+
     L1Factory__ERC20 = await ethers.getContractFactory('ERC20', env.l1Wallet)
     L2Factory__ERC20 = new ethers.ContractFactory(
       L2Artifact.abi,
@@ -55,27 +70,52 @@ describe('Bridged tokens', () => {
       '0x'
     )
     await env.waitForXDomainTransaction(tx, Direction.L1ToL2)
-    expect(await L1__ERC20.balanceOf(l1Wallet.address)).to.deep.equal(
+    expect(await L1__ERC20.balanceOf(env.l1Wallet.address)).to.deep.equal(
       BigNumber.from(999000)
     )
-    expect(await L2__ERC20.balanceOf(l1Wallet.address)).to.deep.equal(
+    expect(await L2__ERC20.balanceOf(env.l2Wallet.address)).to.deep.equal(
       BigNumber.from(1000)
     )
   }).timeout(isLiveNetwork() ? 300_000 : 120_000)
 
-  it('should withdraw tokens from L2', async () => {
+  it('should transfer tokens on L2', async () => {
+    const tx = await L2__ERC20.transfer(otherWalletL1.address, 500)
+    await tx.wait()
+    expect(await L2__ERC20.balanceOf(env.l2Wallet.address)).to.deep.equal(
+      BigNumber.from(500)
+    )
+    expect(await L2__ERC20.balanceOf(otherWalletL2.address)).to.deep.equal(
+      BigNumber.from(500)
+    )
+  })
+
+  it('should withdraw tokens from L2 to the depositor', async () => {
     const tx = await env.l2Bridge.withdraw(
       L2__ERC20.address,
-      1000,
+      500,
       2000000,
       '0x'
     )
     await env.relayXDomainMessages(tx)
     await env.waitForXDomainTransaction(tx, Direction.L2ToL1)
-    expect(await L1__ERC20.balanceOf(l1Wallet.address)).to.deep.equal(
-      BigNumber.from(1000000)
+    expect(await L1__ERC20.balanceOf(env.l1Wallet.address)).to.deep.equal(
+      BigNumber.from(999500)
+    )
+    expect(await L2__ERC20.balanceOf(env.l2Wallet.address)).to.deep.equal(
+      BigNumber.from(0)
+    )
+  }).timeout(isLiveNetwork() ? 300_000 : 120_000)
+
+  it('should withdraw tokens from L2 to the transfer recipient', async () => {
+    const tx = await env.l2Bridge
+      .connect(otherWalletL2)
+      .withdraw(L2__ERC20.address, 500, 2000000, '0x')
+    await env.relayXDomainMessages(tx)
+    await env.waitForXDomainTransaction(tx, Direction.L2ToL1)
+    expect(await L1__ERC20.balanceOf(otherWalletL1.address)).to.deep.equal(
+      BigNumber.from(500)
     )
-    expect(await L2__ERC20.balanceOf(l1Wallet.address)).to.deep.equal(
+    expect(await L2__ERC20.balanceOf(otherWalletL2.address)).to.deep.equal(
       BigNumber.from(0)
     )
   }).timeout(isLiveNetwork() ? 300_000 : 120_000)