Add erc20 decimals and token metadata tooling (#56)

* Add decimals to synthetic ERC20

* Update config and tests for default token metadata

* Update example token config to fetch metadata

* Update with router

* Pull in 1.3.1
---------

Co-authored-by: Asa Oines <[email protected]>

README.md

@@ -2,6 +2,8 @@
 
 This repo contains the base Hyperlane ERC20 and ERC721 tokens (HypERC20 and HypERC721). These tokens extend the base standards with an additional `transferRemote` function. Warp Routes make any token or native asset interchain without custom contracts. Read more about Warp Routes and how to deploy your own at [Warp API docs](https://docs.hyperlane.xyz/docs/developers/warp-api).
 
+**NOTE:** ERC721 collateral variants are assumed to [enumerable](https://docs.openzeppelin.com/contracts/4.x/api/token/erc721#IERC721Enumerable) and [metadata](https://docs.openzeppelin.com/contracts/4.x/api/token/erc721#IERC721Metadata) compliant.
+
 ## Versions
 
 | Git Ref | Release Date | Notes |

configs/warp-route-token-config.json

@@ -8,27 +8,18 @@
   },
   "alfajores": {
     "type": "synthetic",
-    "name": "Weth",
-    "symbol": "WETH",
-    "totalSupply": 0,
     "owner": "0x5bA371aeA18734Cb7195650aFdfCa4f9251aa513",
     "mailbox": "0xCC737a94FecaeC165AbCf12dED095BB13F037685",
     "interchainGasPaymaster": "0xF90cB82a76492614D07B82a7658917f3aC811Ac1"
   },
   "fuji": {
     "type": "synthetic",
-    "name": "Weth",
-    "symbol": "WETH",
-    "totalSupply": 0,
     "owner": "0x5bA371aeA18734Cb7195650aFdfCa4f9251aa513",
     "mailbox": "0xCC737a94FecaeC165AbCf12dED095BB13F037685",
     "interchainGasPaymaster": "0xF90cB82a76492614D07B82a7658917f3aC811Ac1"
   },
   "moonbasealpha": {
     "type": "synthetic",
-    "name": "Weth",
-    "symbol": "WETH",
-    "totalSupply": 0,
     "owner": "0x5bA371aeA18734Cb7195650aFdfCa4f9251aa513",
     "mailbox": "0xCC737a94FecaeC165AbCf12dED095BB13F037685",
     "interchainGasPaymaster": "0xF90cB82a76492614D07B82a7658917f3aC811Ac1"

contracts/HypERC20.sol

@@ -11,6 +11,12 @@ import {ERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/
  * @dev Supply on each chain is not constant but the aggregate supply across all chains is.
  */
 contract HypERC20 is ERC20Upgradeable, TokenRouter {
+    uint8 private immutable _decimals;
+
+    constructor(uint8 decimals) {
+        _decimals = decimals;
+    }
+
     /**
      * @notice Initializes the Hyperlane router, ERC20 metadata, and mints initial supply to deployer.
      * @param _mailbox The address of the mailbox contract.
@@ -37,6 +43,10 @@ contract HypERC20 is ERC20Upgradeable, TokenRouter {
         _mint(msg.sender, _totalSupply);
     }
 
+    function decimals() public view override returns (uint8) {
+        return _decimals;
+    }
+
     /**
      * @dev Burns `_amount` of token from `msg.sender` balance.
      * @inheritdoc TokenRouter

contracts/test/ERC721Test.sol

@@ -1,9 +1,9 @@
 // SPDX-License-Identifier: Apache-2.0
 pragma solidity >=0.8.0;
 
-import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
 
-contract ERC721Test is ERC721 {
+contract ERC721Test is ERC721Enumerable {
     constructor(
         string memory name,
         string memory symbol,

package.json

@@ -1,11 +1,11 @@
 {
   "name": "@hyperlane-xyz/hyperlane-token",
   "description": "A template for interchain ERC20 and ERC721 tokens using Hyperlane",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "dependencies": {
-    "@hyperlane-xyz/core": "1.3.0",
-    "@hyperlane-xyz/sdk": "1.3.0",
-    "@hyperlane-xyz/utils": "1.3.0",
+    "@hyperlane-xyz/core": "1.3.1",
+    "@hyperlane-xyz/sdk": "1.3.1",
+    "@hyperlane-xyz/utils": "1.3.1",
     "@openzeppelin/contracts-upgradeable": "^4.8.0",
     "ethers": "^5.7.2"
   },

src/config.ts

@@ -1,6 +1,6 @@
 import { ethers } from 'ethers';
 
-import { GasRouterConfig, RouterConfig } from '@hyperlane-xyz/sdk';
+import { GasRouterConfig } from '@hyperlane-xyz/sdk';
 
 export enum TokenType {
   synthetic = 'synthetic',
@@ -10,12 +10,25 @@ export enum TokenType {
   native = 'native',
 }
 
-export type SyntheticConfig = {
-  type: TokenType.synthetic | TokenType.syntheticUri;
+export type TokenMetadata = {
   name: string;
   symbol: string;
   totalSupply: ethers.BigNumberish;
 };
+
+export type ERC20Metadata = TokenMetadata & {
+  decimals: number;
+};
+
+export const isTokenMetadata = (metadata: any): metadata is TokenMetadata =>
+  metadata.name && metadata.symbol && metadata.totalSupply !== undefined; // totalSupply can be 0
+
+export const isErc20Metadata = (metadata: any): metadata is ERC20Metadata =>
+  metadata.decimals && isTokenMetadata(metadata);
+
+export type SyntheticConfig = TokenMetadata & {
+  type: TokenType.synthetic | TokenType.syntheticUri;
+};
 export type CollateralConfig = {
   type: TokenType.collateral | TokenType.collateralUri;
   token: string;
@@ -44,19 +57,14 @@ export const isUriConfig = (config: TokenConfig) =>
   config.type === TokenType.syntheticUri ||
   config.type === TokenType.collateralUri;
 
-export type HypERC20Config = Partial<GasRouterConfig> &
-  RouterConfig &
-  TokenConfig;
-export type HypERC20CollateralConfig = Partial<GasRouterConfig> &
-  RouterConfig &
-  CollateralConfig;
-export type HypNativeConfig = Partial<GasRouterConfig> &
-  RouterConfig &
-  NativeConfig;
-
-export type HypERC721Config = Partial<GasRouterConfig> &
-  RouterConfig &
-  TokenConfig;
-export type HypERC721CollateralConfig = Partial<GasRouterConfig> &
-  RouterConfig &
-  CollateralConfig;
+export type HypERC20Config = GasRouterConfig & SyntheticConfig & ERC20Metadata;
+export type HypERC20CollateralConfig = GasRouterConfig & CollateralConfig;
+export type HypNativeConfig = GasRouterConfig & NativeConfig;
+export type ERC20RouterConfig =
+  | HypERC20Config
+  | HypERC20CollateralConfig
+  | HypNativeConfig;
+
+export type HypERC721Config = GasRouterConfig & SyntheticConfig;
+export type HypERC721CollateralConfig = GasRouterConfig & CollateralConfig;
+export type ERC721RouterConfig = HypERC721Config | HypERC721CollateralConfig;