🚧 market: fixed repay

Author: cruzdanilo

package.json

@@ -32,7 +32,7 @@
     "@changesets/types": "^6.1.0",
     "@eslint-community/eslint-plugin-eslint-comments": "^4.5.0",
     "@eslint/js": "^9.28.0",
-    "@exactly/protocol": "^0.2.20",
+    "@exactly/protocol": "exactly/protocol#c5363b6",
     "@openzeppelin/contracts": "^5.3.0",
     "@openzeppelin/contracts-upgradeable": "^5.3.0",
     "@openzeppelin/contracts-upgradeable-v4": "npm:@openzeppelin/contracts-upgradeable@^4.9.6",

pnpm-lock.yaml

@@ -0,0 +1,48 @@
+import min from "../fixed-point-math/min.js";
+import mulDiv from "../fixed-point-math/mulDiv.js";
+import mulWad from "../fixed-point-math/mulWad.js";
+
+export default function fixedRepayAssets(
+  {
+    penaltyRate,
+    backupFeeRate,
+    borrowed,
+    supplied,
+    unassignedEarnings,
+    lastAccrual,
+    principal,
+    fee,
+  }: FixedRepaySnapshot,
+  maturity: bigint,
+  positionAssets: bigint,
+  timestamp = Math.floor(Date.now() / 1000),
+) {
+  const totalPosition = principal + fee;
+  if (totalPosition === 0n) return 0n;
+  if (positionAssets > totalPosition) positionAssets = totalPosition;
+  if (timestamp >= lastAccrual) {
+    return positionAssets + mulWad(positionAssets, (BigInt(timestamp) - lastAccrual) * penaltyRate);
+  }
+  if (maturity > lastAccrual) {
+    unassignedEarnings -= mulDiv(unassignedEarnings, BigInt(timestamp) - lastAccrual, maturity - lastAccrual);
+  }
+  let yieldAssets = 0n;
+  const backupSupplied = borrowed - min(borrowed, supplied);
+  if (backupSupplied) {
+    const scaledPrincipal = mulDiv(positionAssets, principal, principal + fee);
+    yieldAssets = mulDiv(unassignedEarnings, min(scaledPrincipal, backupSupplied), backupSupplied);
+    yieldAssets -= mulWad(yieldAssets, backupFeeRate);
+  }
+  return positionAssets - yieldAssets;
+}
+
+export interface FixedRepaySnapshot {
+  penaltyRate: bigint;
+  backupFeeRate: bigint;
+  borrowed: bigint;
+  supplied: bigint;
+  unassignedEarnings: bigint;
+  lastAccrual: bigint;
+  principal: bigint;
+  fee: bigint;
+}

src/market/fixedRepayAssets.ts

@@ -0,0 +1,44 @@
+import type { FixedRepaySnapshot } from "./fixedRepayAssets.js";
+import WAD from "../fixed-point-math/WAD.js";
+import divWad from "../fixed-point-math/divWad.js";
+import min from "../fixed-point-math/min.js";
+import mulDiv from "../fixed-point-math/mulDiv.js";
+import mulWad from "../fixed-point-math/mulWad.js";
+
+export default function fixedRepayPosition(
+  {
+    penaltyRate,
+    backupFeeRate,
+    borrowed,
+    supplied,
+    unassignedEarnings,
+    lastAccrual,
+    principal,
+    fee,
+  }: FixedRepaySnapshot,
+  maturity: bigint,
+  assets: bigint,
+  timestamp = Math.floor(Date.now() / 1000),
+) {
+  const totalPosition = principal + fee;
+  if (totalPosition === 0n) return 0n;
+  if (timestamp >= lastAccrual) {
+    return min(divWad(assets, WAD + (BigInt(timestamp) - maturity) * penaltyRate), totalPosition);
+  }
+  if (assets >= totalPosition) return totalPosition;
+  if (maturity > lastAccrual) {
+    unassignedEarnings -= mulDiv(unassignedEarnings, BigInt(timestamp) - lastAccrual, maturity - lastAccrual);
+  }
+  if (unassignedEarnings === 0n) return assets;
+  const backupSupplied = borrowed - min(borrowed, supplied);
+  if (backupSupplied === 0n) return assets;
+  const k = divWad(principal, totalPosition);
+  if (k === 0n) return assets;
+  const netUnassignedEarnings = mulWad(unassignedEarnings, WAD - backupFeeRate);
+  if (netUnassignedEarnings === 0n) return assets;
+  const r = mulDiv(netUnassignedEarnings, k, backupSupplied);
+  if (r >= WAD) return min(assets + netUnassignedEarnings, totalPosition);
+  const x = divWad(assets, WAD - r);
+  if (mulWad(k, x) <= backupSupplied && x <= totalPosition) return x;
+  return min(assets + netUnassignedEarnings, totalPosition);
+}

src/market/fixedRepayPosition.ts

@@ -1,8 +1,10 @@
-import { describe, expect, inject, it } from "vitest";
+import { zeroAddress } from "viem";
+import { beforeEach, describe, expect, inject, it } from "vitest";
 
-import { marketUsdcAbi, ratePreviewerAbi } from "./generated/contracts.js";
+import { integrationPreviewerAbi, marketUsdcAbi, ratePreviewerAbi } from "./generated/contracts.js";
 import anvilClient from "./utils/anvilClient.js";
 import divWad from "../src/fixed-point-math/divWad.js";
+import type { FixedRepaySnapshot } from "../src/market/fixedRepayAssets.js";
 import floatingDepositRates from "../src/market/floatingDepositRates.js";
 
 describe("floating deposit rate", () => {
@@ -48,3 +50,16 @@ describe("floating deposit rate", () => {
     expect(usdcRate).toBe(rate);
   });
 });
+
+describe("fixed repay", () => {
+  let snapshot: FixedRepaySnapshot;
+
+  beforeEach(async () => {
+    snapshot = await anvilClient.readContract({
+      address: inject("IntegrationPreviewer"),
+      functionName: "fixedRepaySnapshot",
+      args: [zeroAddress, inject("MarketUSDC"), 0n],
+      abi: integrationPreviewerAbi,
+    });
+  });
+})

test/market.test.ts

@@ -10,6 +10,7 @@ import { MockBalancerVault } from "@exactly/protocol/mocks/MockBalancerVault.sol
 import { MockPriceFeed } from "@exactly/protocol/mocks/MockPriceFeed.sol";
 import { Previewer } from "@exactly/protocol/periphery/Previewer.sol";
 import { RatePreviewer } from "@exactly/protocol/periphery/RatePreviewer.sol";
+import { IntegrationPreviewer } from "@exactly/protocol/periphery/IntegrationPreviewer.sol";
 
 import { ERC1967Proxy } from "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
 
@@ -27,6 +28,7 @@ contract DeployProtocol is Script {
   MockWETH public weth;
   Previewer public previewer;
   RatePreviewer public ratePreviewer;
+  IntegrationPreviewer public integrationPreviewer;
 
   MockBalancerVault public balancer;
 
@@ -78,6 +80,7 @@ contract DeployProtocol is Script {
 
     previewer = new Previewer(auditor, IPriceFeed(address(0)));
     ratePreviewer = new RatePreviewer(auditor);
+    integrationPreviewer = new IntegrationPreviewer(auditor);
 
     balancer = new MockBalancerVault();
     exa.mint(address(balancer), 1_000_000e18);

test/utils/Protocol.s.sol

@@ -28,10 +28,18 @@ export default async function setup({ provide }: TestProject) {
       --sender ${deployer} --unlocked ${deployer} --rpc-url ${foundry.rpcUrls.default.http[0]} --broadcast --slow`;
   }
 
-  // eslint-disable-next-line unicorn/no-unreadable-array-destructuring
-  const [, , , , , , , , , , , usdc, , marketUSDC, , , , , , , , marketWETH, , , , , , previewer, ratePreviewer] =
-    parse(Protocol, await import(`broadcast/Protocol.s.sol/${String(foundry.id)}/run-latest.json`)).transactions;
+  const protocol = parse(
+    Protocol,
+    await import(`broadcast/Protocol.s.sol/${String(foundry.id)}/run-latest.json`),
+  ).transactions;
+  const usdc = protocol[11];
+  const marketUSDC = protocol[13];
+  const marketWETH = protocol[21];
+  const previewer = protocol[27];
+  const ratePreviewer = protocol[28];
+  const integrationPreviewer = protocol[29];
 
+  provide("IntegrationPreviewer", integrationPreviewer.contractAddress);
   provide("MarketUSDC", marketUSDC.contractAddress);
   provide("MarketWETH", marketWETH.contractAddress);
   provide("Previewer", previewer.contractAddress);
@@ -84,6 +92,11 @@ const Protocol = object({
     object({ transactionType: literal("CALL") }),
     object({ transactionType: literal("CREATE"), contractName: literal("Previewer"), contractAddress: Address }),
     object({ transactionType: literal("CREATE"), contractName: literal("RatePreviewer"), contractAddress: Address }),
+    object({
+      transactionType: literal("CREATE"),
+      contractName: literal("IntegrationPreviewer"),
+      contractAddress: Address,
+    }),
     object({
       transactionType: literal("CREATE"),
       contractName: literal("MockBalancerVault"),
@@ -94,6 +107,7 @@ const Protocol = object({
 
 declare module "vitest" {
   export interface ProvidedContext {
+    IntegrationPreviewer: Address;
     MarketUSDC: Address;
     MarketWETH: Address;
     Previewer: Address;

test/utils/anvil.ts

@@ -5,6 +5,7 @@ import type { Abi } from "viem";
 export default defineConfig({
   out: "test/generated/contracts.ts",
   contracts: [
+    { name: "IntegrationPreviewer", abi: loadDeployment("IntegrationPreviewer").abi },
     { name: "Previewer", abi: loadDeployment("Previewer").abi },
     { name: "RatePreviewer", abi: loadDeployment("RatePreviewer").abi },
     { name: "MarketUSDC", abi: loadDeployment("MarketUSDC").abi },