Merge pull request #415 from GridPlus/dl/chain-json

GridPlus · Jun 22, 2022 · 58b8de5 · 58b8de5
2 parents bf36e80 + 706bc72
commit 58b8de5
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Showing 2 changed files with 54 additions and 4 deletions.
diff --git a/src/constants.ts b/src/constants.ts
@@ -528,22 +528,29 @@ function getFwVersionConst (v) {
 // eslint-disable-next-line no-control-regex
 const ASCII_REGEX = /^[\x00-\x7F]+$/;
 
+const EXTERNAL_NETWORKS_BY_CHAIN_ID_URL =
+  'https://gridplus.github.io/chains/chains.json';
+
 const NETWORKS_BY_CHAIN_ID = {
   1: {
     name: 'ethereum',
     baseUrl: 'https://api.etherscan.io',
+    apiRoute: 'api?module=contract&action=getabi',
   },
   137: {
     name: 'polygon',
     baseUrl: 'https://api.polygonscan.com',
+    apiRoute: 'api?module=contract&action=getabi',
   },
   56: {
     name: 'binance',
     baseUrl: 'https://api.bscscan.com',
+    apiRoute: 'api?module=contract&action=getabi',
   },
   43114: {
     name: 'avalanche',
     baseUrl: 'https://api.snowtrace.io',
+    apiRoute: 'api?module=contract&action=getabi',
   },
 };
 
@@ -555,6 +562,7 @@ export {
   BIP_CONSTANTS,
   BASE_URL,
   NETWORKS_BY_CHAIN_ID,
+  EXTERNAL_NETWORKS_BY_CHAIN_ID_URL,
   ENC_MSG_LEN,
   addressSizes,
   decResLengths,

diff --git a/src/util.ts b/src/util.ts
@@ -20,7 +20,8 @@ import {
   HARDENED_OFFSET,
   responseCodes,
   responseMsgs,
-  VERSION_BYTE
+  VERSION_BYTE,
+  EXTERNAL_NETWORKS_BY_CHAIN_ID_URL,
 } from './constants';
 const { COINS, PURPOSES } = BIP_CONSTANTS;
 const EC = elliptic.ec;
@@ -409,6 +410,45 @@ export const getV = function (tx, resp) {
   return chainId.muln(2).addn(35).addn(recovery);
 }
 
+/**
+ * Fetches an external JSON file containing networks indexed by chain id from a GridPlus repo, and
+ * returns the parsed JSON.
+ */
+async function fetchExternalNetworkForChainId (
+  chainId: number | string,
+): Promise<{
+  [key: string]: {
+    name: string;
+    baseUrl: string;
+    apiRoute: string;
+  };
+}> {
+  try {
+    const response = await superagent.get(EXTERNAL_NETWORKS_BY_CHAIN_ID_URL);
+    if (response && response.body) {
+      return response.body[chainId];
+    } else {
+      return undefined;
+    }
+  } catch (err) {
+    console.warn('Fetching external networks failed.\n', err);
+  }
+}
+
+/** 
+ * Builds a URL for fetching calldata from block explorers for any supported chains 
+ * */
+function buildUrlForSupportedChainAndAddress ({ supportedChain, address }) {
+  const baseUrl = supportedChain.baseUrl;
+  const apiRoute = supportedChain.apiRoute;
+  const urlWithRoute = `${baseUrl}/${apiRoute}&address=${address}`;
+
+  const apiKey = process.env.ETHERSCAN_KEY;
+  const apiKeyParam = apiKey ? `&apiKey=${process.env.ETHERSCAN_KEY}` : '';
+
+  return urlWithRoute + apiKeyParam
+}
+
 /**
  *  Fetches calldata from a remote scanner based on the transaction's `chainId`
  */
@@ -432,10 +472,12 @@ export async function fetchCalldataDecoder (_data: Uint8Array | string, to: stri
     // Convert the chainId to a number and use it to determine if we can call out to
     // an etherscan-like explorer for richer data.
     const chainId = Number(_chainId);
-    const supportedChain = NETWORKS_BY_CHAIN_ID[chainId];
+    const cachedNetwork = NETWORKS_BY_CHAIN_ID[chainId];
+    const supportedChain = cachedNetwork
+      ? cachedNetwork
+      : await fetchExternalNetworkForChainId(chainId);
     if (supportedChain) {
-      const baseUrl = supportedChain.baseUrl;
-      const url = `${baseUrl}/api?module=contract&action=getabi&address=${to}&apiKey=${process.env.ETHERSCAN_KEY}`
+      const url = buildUrlForSupportedChainAndAddress({ supportedChain, address: to })
       const response = await superagent
         .get(url)
         .catch(err => {