fix(protocol): use "onlyInitializable" modifier instead of "initializer"

refactor(protocol): mark init function as "internal" in OwnableUpgradeable
refactor(protocol): rename "__OwnableUpgradeable_init" to "__Ownable_init"
test(protocol): new GodModeOwnableUpgradeable to expose init function

See releated discussion in OpenZeppelin/openzeppelin-contracts#3006

packages/protocol/contracts/access/OwnableUpgradeable.sol

@@ -32,7 +32,7 @@ contract OwnableUpgradeable is
 
     /// @notice The upgradeability variant of the contract constructor.
     /// @dev Sets the deployer as the initial owner.
-    function __OwnableUpgradeable__init() public initializer {
+    function __Ownable_init() internal initializer {
         owner = msg.sender;
         emit TransferOwnership(address(0), msg.sender);
     }

packages/protocol/contracts/core/balance-sheet/BalanceSheetV2.sol

@@ -30,7 +30,7 @@ contract BalanceSheetV2 is
     /// @param oracle_ The address of the oracle contract.
     function initialize(IFintroller fintroller_, IChainlinkOperator oracle_) public initializer {
         // Initialize the owner.
-        OwnableUpgradeable.__OwnableUpgradeable__init();
+        __Ownable_init();
 
         // Set the Fintroller contract.
         fintroller = fintroller_;

packages/protocol/contracts/test/GodModeOwnableUpgradeable.sol

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+pragma solidity >=0.8.4;
+
+import "../access/OwnableUpgradeable.sol";
+
+/// @title GodModeOwnableUpgradeable
+/// @author Hifi
+/// @dev Strictly for test purposes. Do not use in production.
+contract GodModeOwnableUpgradeable is OwnableUpgradeable {
+    function __godMode_Ownable_init() public {
+        __Ownable_init();
+    }
+}

packages/protocol/test/shared/deployers.ts

@@ -1,5 +1,5 @@
 import type { Signer } from "@ethersproject/abstract-signer";
-import { BigNumber } from "@ethersproject/bignumber";
+import type { BigNumber } from "@ethersproject/bignumber";
 import { artifacts, ethers, upgrades, waffle } from "hardhat";
 import type { Artifact } from "hardhat/types";
 
@@ -14,14 +14,16 @@ import {
   WBTC_SYMBOL,
 } from "@hifi/constants";
 import { getHTokenName, getHTokenSymbol, price } from "@hifi/helpers";
-import { GodModeBalanceSheet__factory, OwnableUpgradeable, OwnableUpgradeable__factory } from "../../src/types";
-import { ChainlinkOperator } from "../../src/types/ChainlinkOperator";
-import { Fintroller } from "../../src/types/Fintroller";
-import { GodModeBalanceSheet } from "../../src/types/GodModeBalanceSheet";
-import { GodModeErc20 } from "../../src/types/GodModeErc20";
-import { GodModeHToken } from "../../src/types/GodModeHToken";
-import { HToken } from "../../src/types/HToken";
-import { SimplePriceFeed } from "../../src/types/SimplePriceFeed";
+import type { GodModeBalanceSheet__factory } from "../../src/types/factories/GodModeBalanceSheet__factory";
+import type { GodModeOwnableUpgradeable__factory } from "../../src/types/factories/GodModeOwnableUpgradeable__factory";
+import type { ChainlinkOperator } from "../../src/types/ChainlinkOperator";
+import type { Fintroller } from "../../src/types/Fintroller";
+import type { GodModeBalanceSheet } from "../../src/types/GodModeBalanceSheet";
+import type { GodModeErc20 } from "../../src/types/GodModeErc20";
+import type { GodModeHToken } from "../../src/types/GodModeHToken";
+import type { GodModeOwnableUpgradeable } from "../../src/types/GodModeOwnableUpgradeable";
+import type { HToken } from "../../src/types/HToken";
+import type { SimplePriceFeed } from "../../src/types/SimplePriceFeed";
 
 const { deployContract } = waffle;
 const overrides = { gasLimit: process.env.CODE_COVERAGE ? GAS_LIMITS.coverage : GAS_LIMITS.hardhat };
@@ -106,9 +108,11 @@ export async function deployGodModeHToken(
   return hToken;
 }
 
-export async function deployOwnableUpgradeable(): Promise<OwnableUpgradeable> {
-  const ownableUpgradeableFactory: OwnableUpgradeable__factory = await ethers.getContractFactory("OwnableUpgradeable");
-  const ownableUpgradeable: OwnableUpgradeable = <OwnableUpgradeable>(
+export async function deployOwnableUpgradeable(): Promise<GodModeOwnableUpgradeable> {
+  const ownableUpgradeableFactory: GodModeOwnableUpgradeable__factory = await ethers.getContractFactory(
+    "GodModeOwnableUpgradeable",
+  );
+  const ownableUpgradeable: GodModeOwnableUpgradeable = <GodModeOwnableUpgradeable>(
     await upgrades.deployProxy(ownableUpgradeableFactory)
   );
   await ownableUpgradeable.deployed();

packages/protocol/test/shared/fixtures.ts

@@ -18,7 +18,7 @@ import type { Fintroller } from "../../src/types/Fintroller";
 import type { GodModeBalanceSheet } from "../../src/types/GodModeBalanceSheet";
 import type { GodModeErc20 } from "../../src/types/GodModeErc20";
 import type { GodModeHToken } from "../../src/types/GodModeHToken";
-import type { OwnableUpgradeable } from "../../src/types/OwnableUpgradeable";
+import type { GodModeOwnableUpgradeable } from "../../src/types/GodModeOwnableUpgradeable";
 import type { SimplePriceFeed } from "../../src/types/SimplePriceFeed";
 import {
   deployChainlinkOperator,
@@ -190,10 +190,10 @@ export async function unitFixtureHToken(signers: Signer[]): Promise<UnitFixtureH
 }
 
 type UnitFixtureOwnableUpgradeable = {
-  ownableUpgradeable: OwnableUpgradeable;
+  ownableUpgradeable: GodModeOwnableUpgradeable;
 };
 
 export async function unitFixtureOwnableUpgradeable(): Promise<UnitFixtureOwnableUpgradeable> {
-  const ownableUpgradeable: OwnableUpgradeable = await deployOwnableUpgradeable();
+  const ownableUpgradeable: GodModeOwnableUpgradeable = await deployOwnableUpgradeable();
   return { ownableUpgradeable };
 }

packages/protocol/test/shared/types.ts

@@ -7,7 +7,7 @@ import type { Fintroller } from "../../src/types/Fintroller";
 import type { GodModeBalanceSheet } from "../../src/types/GodModeBalanceSheet";
 import type { GodModeErc20 } from "../../src/types/GodModeErc20";
 import type { GodModeHToken } from "../../src/types/GodModeHToken";
-import type { OwnableUpgradeable } from "../../src/types/OwnableUpgradeable";
+import type { GodModeOwnableUpgradeable } from "../../src/types/GodModeOwnableUpgradeable";
 import type { SimplePriceFeed } from "../../src/types/SimplePriceFeed";
 
 declare module "mocha" {
@@ -24,7 +24,7 @@ export interface Contracts {
   fintroller: Fintroller;
   hTokens: GodModeHToken[];
   oracle: ChainlinkOperator;
-  ownableUpgradeable: OwnableUpgradeable;
+  ownableUpgradeable: GodModeOwnableUpgradeable;
   usdc: GodModeErc20;
   usdcPriceFeed: SimplePriceFeed;
   wbtc: GodModeErc20;

packages/protocol/test/unit/ownable-upgradeable/effects/renounceOwnership.ts

@@ -4,7 +4,7 @@ import { expect } from "chai";
 
 export function shouldBehaveLikeRenounceOwnership(): void {
   beforeEach(async function () {
-    await this.contracts.ownableUpgradeable.connect(this.signers.admin).__OwnableUpgradeable__init();
+    await this.contracts.ownableUpgradeable.connect(this.signers.admin).__godMode_Ownable_init();
   });
 
   context("when the caller is not the owner", function () {

packages/protocol/test/unit/ownable-upgradeable/effects/transferOwnership.ts

@@ -5,7 +5,7 @@ import { expect } from "chai";
 
 export function shouldBehaveLikeTransferOwnership(): void {
   beforeEach(async function () {
-    await this.contracts.ownableUpgradeable.connect(this.signers.admin).__OwnableUpgradeable__init();
+    await this.contracts.ownableUpgradeable.connect(this.signers.admin).__godMode_Ownable_init();
   });
 
   context("when the caller is not the owner", function () {

packages/protocol/test/unit/ownable-upgradeable/view/owner.ts

@@ -11,7 +11,7 @@ export function shouldBehaveLikeOwnerGetter(): void {
 
   context("when the contract was initialized", function () {
     beforeEach(async function () {
-      await this.contracts.ownableUpgradeable.connect(this.signers.admin).__OwnableUpgradeable__init();
+      await this.contracts.ownableUpgradeable.connect(this.signers.admin).__godMode_Ownable_init();
     });
 
     it("returns the correct address", async function () {