Add snapshot tests + refactor to Halo

test/halo/Halo.ts

@@ -1,32 +1,42 @@
+import {SnapshotRestorer, takeSnapshot} from "@nomicfoundation/hardhat-network-helpers";
 import {SignerWithAddress} from "@nomiclabs/hardhat-ethers/signers";
 import {expect} from "chai";
 import {BigNumber, Wallet} from "ethers";
 import hre from "hardhat";
 import {Halo, Halo__factory} from "typechain-types";
 import {getProxyAdminOwner, getSigners} from "utils";
 
-describe("Halo token", function () {
-  let Halo: Halo__factory;
+describe("Halo", function () {
+  const INITIALSUPPLY = BigNumber.from(10).pow(27); // 1 billion tokens with 18 decimals
 
   let deployer: SignerWithAddress;
   let proxyAdmin: SignerWithAddress | Wallet;
   let user: SignerWithAddress;
 
-  describe("upon Deployment", async function () {
-    let halo: Halo;
-    let INITIALSUPPLY = BigNumber.from(10).pow(27); // 1 billion tokens with 18 decimals
-
-    beforeEach(async function () {
-      const signers = await getSigners(hre);
-      deployer = signers.deployer;
-      proxyAdmin = await getProxyAdminOwner(hre);
-      user = signers.apTeam1;
-
-      Halo = (await hre.ethers.getContractFactory("Halo", deployer)) as Halo__factory;
-      halo = await Halo.deploy();
-      await halo.deployed();
-    });
+  let halo: Halo;
+
+  before(async function () {
+    const signers = await getSigners(hre);
+    deployer = signers.deployer;
+    user = signers.apTeam1;
+
+    proxyAdmin = await getProxyAdminOwner(hre);
+
+    const Halo = new Halo__factory(deployer);
+    halo = await Halo.deploy();
+  });
 
+  let snapshot: SnapshotRestorer;
+
+  beforeEach(async () => {
+    snapshot = await takeSnapshot();
+  });
+
+  afterEach(async () => {
+    await snapshot.restore();
+  });
+
+  describe("upon Deployment", async function () {
     it("Sends the specified amount to the specified recipient", async function () {
       expect(await halo.balanceOf(deployer.address)).to.equal(INITIALSUPPLY);
     });
@@ -38,7 +48,9 @@ describe("Halo token", function () {
     });
     it("Token holder can burn tokens", async function () {
       const burnAmount = BigNumber.from(100000);
-      expect(await halo.burn(burnAmount)).to.emit(halo, "Burn");
+      await expect(halo.burn(burnAmount))
+        .to.emit(halo, "Transfer")
+        .withArgs(await halo.signer.getAddress(), hre.ethers.constants.AddressZero, burnAmount);
       expect(await halo.totalSupply()).to.equal(INITIALSUPPLY.sub(burnAmount));
     });
   });