Merge pull request #15 from trustwallet/feat/erc20-permit-visualizati…

…on-support

feat: add ERC20 permit for both legacy

src/types/index.ts

@@ -58,3 +58,14 @@ export type Protocol<T> = {
   visualize: (message: T, domain: Domain) => Result;
   isCorrectDomain: (domain: Domain) => boolean;
 };
+
+export type PermitMessage = {
+  owner?: string;
+  holder?: string;
+  spender: string;
+  nonce: string;
+  value?: string;
+  deadline?: string;
+  expiry?: string;
+  allowed?: boolean | string;
+};

src/utils/index.ts

@@ -13,6 +13,10 @@ export const isSameAddress = (address1: string, address2: string): boolean => {
   );
 };
 
+export const MaxUint256 = BigInt(
+  "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+);
+
 export const abiCoder = new AbiCoder();
 
 // export const decodeErrorMessage = (output: string): string => {

src/visualizer/erc20-permit/index.ts

@@ -0,0 +1,53 @@
+import { ASSET_TYPE, Domain, PermitMessage, Result } from "../../types";
+import { PROTOCOL_ID } from "..";
+import { MaxUint256 } from "../../utils";
+
+export const visualize = (message: PermitMessage, domain: Domain): Result => {
+  if (!isERC20Permit(message)) throw new Error("wrong ERC20 Permit message schema");
+  const amount =
+    message.value?.toString() ||
+    (message.allowed?.toString() === "true" ? MaxUint256.toString() : "0");
+
+  return {
+    protocol: PROTOCOL_ID.ERC20_PERMIT,
+    assetIn: [],
+    assetOut: [],
+    approval: [
+      {
+        address: domain.verifyingContract,
+        type: ASSET_TYPE.ERC20,
+        amounts: [amount],
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        owner: message.owner || message.holder!, // isERC20Permit makes sure one of theme exist at least
+        operator: message.spender,
+        deadline: Number(message.deadline || message.expiry) * 1000,
+      },
+    ],
+  };
+};
+
+/**
+ * @dev a function that return if a message is an ERC2612 or pseudo-ERC2612 (DAI example)
+ *      This function handles ERC2612 Permit and DAI Permit
+ * @see https://eips.ethereum.org/EIPS/eip-2612
+ * @param message EIP-712 message
+ * @returns Boolean
+ */
+export const isERC20Permit = (message: object): boolean => {
+  if (Object.keys(message).length !== 5) return false;
+  const hasOwnProperty = Object.prototype.hasOwnProperty.bind(message);
+  return (
+    (hasOwnProperty("owner") || hasOwnProperty("holder")) &&
+    hasOwnProperty("spender") &&
+    (hasOwnProperty("value") || hasOwnProperty("allowed")) &&
+    hasOwnProperty("nonce") &&
+    (hasOwnProperty("deadline") || hasOwnProperty("expiry"))
+  );
+};
+
+const erc20Permit = {
+  visualize,
+  isERC20Permit,
+};
+
+export default erc20Permit;

src/visualizer/index.ts

@@ -1,15 +1,20 @@
-import { Domain, Result } from "../types";
+
+import { Domain, PermitMessage, Result } from "../types";
+
+import { SeaPortPayload } from "../types/seaport";
 import { BlurIoOrder } from "../types/blur";
 import { LooksrareMakerOrderWithEncodedParams } from "../types/looksrare";
-import { SeaPortPayload } from "../types/seaport";
+
 import blurIo from "./blur-io";
+import erc20Permit from "./erc20-permit";
 import looksrare from "./looksrare";
 import seaport from "./seaport";
 
 export enum PROTOCOL_ID {
   OPENSEA_SEAPORT = "OPENSEA_SEAPORT",
   LOOKSRARE_EXCHANGE = "LOOKSRARE_EXCHANGE",
   BLUR_IO_MARKETPLACE = "BLUR_IO_MARKETPLACE",
+  ERC20_PERMIT = "ERC20_PERMIT",
 }
 
 export const getProtocolId = (domain: Domain): PROTOCOL_ID | undefined => {
@@ -26,7 +31,10 @@ export const getProtocolId = (domain: Domain): PROTOCOL_ID | undefined => {
  * @returns {Result} assets impact and message liveness
  * @throws {Error}
  */
-export default async function visualize<T>(message: T, domain: Domain): Promise<Result> {
+export default async function visualize<T extends object>(
+  message: T,
+  domain: Domain
+): Promise<Result> {
   const protocolId = getProtocolId(domain);
 
   switch (protocolId) {
@@ -40,6 +48,10 @@ export default async function visualize<T>(message: T, domain: Domain): Promise<
       return blurIo.visualize(message as BlurIoOrder, domain);
 
     default:
+      if (erc20Permit.isERC20Permit(message)) {
+        return erc20Permit.visualize(message as PermitMessage, domain);
+      }
+
       throw new Error("Unrecognized/Unsupported Protocol Domain");
   }
 }

test/visualizer/erc20-permit/index.test.ts

@@ -0,0 +1,104 @@
+import { PermitMessage } from "../../../src/types";
+import visualize from "../../../src/visualizer";
+import erc20Permit from "../../../src/visualizer/erc20-permit";
+
+describe("ERC20 Permit", () => {
+  const erc20DaiPermitMessage = {
+    holder: "0x36C1625E5Ee6FBFa9fadd4f75790275e5eaB7107",
+    spender: "0x21C1625E5Ee6FBFa9fadd4f75790275e5eaB7009",
+    allowed: true,
+    nonce: "1",
+    expiry: "167960665",
+  };
+
+  const ERC2612Message = {
+    owner: "0x36C1625E5Ee6FBFa9fadd4f75790275e5eaB7107",
+    spender: "0x21C1625E5Ee6FBFa9fadd4f75790275e5eaB7009",
+    value: "100000000000",
+    nonce: "1",
+    deadline: "167960665",
+  };
+  const erc20PermitDomain = {
+    name: "Dai Stablecoin",
+    version: "1.1",
+    chainId: "1",
+    verifyingContract: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+  };
+
+  it("should revert if erc20Permit module called with wrong message payload", () => {
+    const deepCopiedMessage = JSON.parse(JSON.stringify(erc20DaiPermitMessage));
+    delete deepCopiedMessage["expiry"];
+
+    expect(() => {
+      erc20Permit.visualize(deepCopiedMessage, erc20PermitDomain);
+    }).toThrowError("wrong ERC20 Permit message schema");
+  });
+
+  it("should successfully visualize DAI approval", async () => {
+    const result = await visualize<PermitMessage>(
+      erc20DaiPermitMessage,
+      erc20PermitDomain
+    );
+
+    expect(result).toEqual({
+      protocol: "ERC20_PERMIT",
+      assetIn: [],
+      assetOut: [],
+      approval: [
+        {
+          address: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+          type: "ERC20",
+          amounts: [
+            "115792089237316195423570985008687907853269984665640564039457584007913129639935",
+          ],
+          owner: "0x36C1625E5Ee6FBFa9fadd4f75790275e5eaB7107",
+          operator: "0x21C1625E5Ee6FBFa9fadd4f75790275e5eaB7009",
+          deadline: 167960665000,
+        },
+      ],
+    });
+  });
+
+  it("should successfully visualize DAI approval with zero amount", async () => {
+    const result = await visualize<PermitMessage>(
+      { ...erc20DaiPermitMessage, allowed: false, nonce: "2" },
+      erc20PermitDomain
+    );
+
+    expect(result).toEqual({
+      protocol: "ERC20_PERMIT",
+      assetIn: [],
+      assetOut: [],
+      approval: [
+        {
+          address: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+          type: "ERC20",
+          amounts: ["0"],
+          owner: "0x36C1625E5Ee6FBFa9fadd4f75790275e5eaB7107",
+          operator: "0x21C1625E5Ee6FBFa9fadd4f75790275e5eaB7009",
+          deadline: 167960665000,
+        },
+      ],
+    });
+  });
+
+  it("should successfully visualize ERC2612 approval", async () => {
+    const result = await visualize<PermitMessage>(ERC2612Message, erc20PermitDomain);
+
+    expect(result).toEqual({
+      protocol: "ERC20_PERMIT",
+      assetIn: [],
+      assetOut: [],
+      approval: [
+        {
+          address: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+          type: "ERC20",
+          amounts: ["100000000000"],
+          owner: "0x36C1625E5Ee6FBFa9fadd4f75790275e5eaB7107",
+          operator: "0x21C1625E5Ee6FBFa9fadd4f75790275e5eaB7009",
+          deadline: 167960665000,
+        },
+      ],
+    });
+  });
+});