add test ensuring storage is preserved on upgrade

test/e2e/upgradeAuthenticator.test.ts

@@ -1,25 +1,30 @@
 import { expect } from "chai";
 import { Contract, Wallet } from "ethers";
-import { deployments, ethers } from "hardhat";
+import { deployments, ethers, waffle } from "hardhat";
+import { setupSolversTask } from "../../src/tasks/solvers";
 
 import { SALT } from "../../src/ts";
 
 import { deployTestContracts } from "./fixture";
 
-describe("Upgrading", () => {
+describe("Upgrade Authenticator", () => {
   let authenticator: Contract;
   let deployer: Wallet;
   let owner: Wallet;
+  let solver: Wallet;
 
   beforeEach(async () => {
     ({ authenticator, deployer, owner } = await deployTestContracts());
+    // Solver isn't a named account
+    solver = waffle.provider.getWallets()[2];
   });
 
   it("should upgrade authenticator", async () => {
     const GPv2AllowListAuthenticationV2 = await ethers.getContractFactory(
       "GPv2AllowListAuthenticationV2",
       deployer,
     );
+    // Note that, before the upgrade this is actually the old instance
     const authenticatorV2 = GPv2AllowListAuthenticationV2.attach(
       authenticator.address,
     );
@@ -34,6 +39,27 @@ describe("Upgrading", () => {
     expect(await authenticatorV2.newMethod()).to.equal(1337);
   });
 
+  it("should preserve storage", async () => {
+    authenticator.connect(owner).addSolver(solver.address);
+
+    // Upgrade after storage is set.
+    await upgrade(
+      "GPv2AllowListAuthentication",
+      "GPv2AllowListAuthenticationV2",
+    );
+
+    const GPv2AllowListAuthenticationV2 = await ethers.getContractFactory(
+      "GPv2AllowListAuthenticationV2",
+      deployer,
+    );
+    const authenticatorV2 = GPv2AllowListAuthenticationV2.attach(
+      authenticator.address,
+    );
+    // Both, the listed solvers and original manager are still set
+    expect(await authenticatorV2.isSolver(solver.address)).to.equal(true);
+    expect(await authenticatorV2.manager()).to.equal(owner.address);
+  });
+
   async function upgrade(contractName: string, newContractName: string) {
     await deployments.deploy(contractName, {
       contract: newContractName,