feat(farcaster): enable offchain resolver to farcaster names #194

package.json

@@ -37,7 +37,7 @@
     "eslint": "^6.7.2",
     "express": "^4.17.1",
     "jsdom": "^19.0.0",
-    "node-fetch": "v2.7.0",
+    "node-fetch": "^2.7.0",
     "nodemon": "^2.0.7",
     "redis": "^4.6.10",
     "sharp": "^0.30.1",
@@ -48,6 +48,7 @@
     "@types/express": "^4.17.11",
     "@types/jest": "^28.1.0",
     "@types/node": "^14.14.21",
+    "@types/node-fetch": "^2.6.11",
     "@typescript-eslint/eslint-plugin": "^2.33.0",
     "@typescript-eslint/parser": "^2.33.0",
     "eslint-plugin-prettier": "^3.1.3",

src/addressResolvers/farcaster.ts

@@ -0,0 +1,144 @@
+import { capture } from '@snapshot-labs/snapshot-sentry';
+import { Address, Handle, FetchError, isSilencedError, isEvmAddress } from './utils';
+import { getAddress } from '@ethersproject/address';
+import fetch from 'node-fetch';
+
+export const NAME = 'Farcaster';
+const FNAMES_API_URL = 'https://fnames.farcaster.xyz/transfers?name=';
+const NEYNAR_API_URL = 'https://api.neynar.com/v2/farcaster/user/';
+const API_KEY = process.env.NEYNAR_API_KEY ?? '';
+
+interface UserDetails {
+  username: Handle;
+  verified_addresses: {
+    eth_addresses: Address[];
+    sol_addresses: string[];
+  };
+  pfp_url: string;
+}
+
+interface ApiResponse {
+  [address: string]: UserDetails[];
+}
+
+interface UserResult {
+  username?: Handle;
+  eth_addresses?: Address[];
+  sol_addresses?: string[];
+  pfp_url?: string;
+}
+
+async function fetchData<T>(url: string): Promise<T> {
+  const headers = {
+    Accept: 'application/json',
+    api_key: API_KEY
+  };
+  const response = await fetch(url, { headers });
+  if (!response.ok) {
+    const e = new FetchError(`Failed to fetch data from the API. Status: ${response.status}`);
+    if (!isSilencedError(e)) {
+      capture(e, { tags: { issue: 'api_fetch_failure' } });
+    }
+    throw e;
+  }
+  return response.json() as Promise<T>;
+}
+
+function isValidUserData(data: any): boolean {
+  return Array.isArray(data) && data.length > 0 && data[0].username;
+}
+
+function formatUserDetails(userDetails: { users: UserDetails[] }): UserResult {
+  const user = userDetails.users[0];
+  return {
+    username: user.username,
+    eth_addresses: user.verified_addresses.eth_addresses.filter(isEvmAddress),
+    sol_addresses: user.verified_addresses.sol_addresses,
+    pfp_url: user.pfp_url
+  };
+}
+
+async function getUserDetails(username: Handle): Promise<{ users: UserDetails[] } | null> {
+  const transferData = await fetchData<{ transfers: any[] }>(`${FNAMES_API_URL}${username}`);
+  if (transferData.transfers.length > 0) {
+    const userDetails = await fetchData<{ result: { users: UserDetails[] } }>(
+      `${NEYNAR_API_URL}search?q=${username}&viewer_fid=197049`
+    );
+    if (userDetails.result && userDetails.result.users.length > 0) {
+      return userDetails.result;
+    }
+  }
+  return null;
+}
+
+function handleUserDetailsError(e: any, username: Handle): void {
+  if (!isSilencedError(e)) {
+    capture(e, { input: { username }, tags: { issue: 'fetch_user_details_failure' } });
+  }
+  throw new FetchError(`Error fetching user details for ${username}.`);
+}
+
+async function fetchUserDetailsByUsername(username: Handle): Promise<UserResult | null> {
+  try {
+    const userDetails = await getUserDetails(username);
+    if (userDetails) {
+      return formatUserDetails(userDetails);
+    }
+  } catch (e) {
+    handleUserDetailsError(e, username);
+  }
+  return null;
+}
+
+function buildLookupUrl(addresses: Address[]): string {
+  const filteredAddresses = addresses.filter(isEvmAddress);
+  if (filteredAddresses.length === 0) {
+    throw new FetchError('No valid Ethereum addresses provided.');
+  }
+  const addressesQuery = filteredAddresses.join(',');
+  return `${NEYNAR_API_URL}bulk-by-address?addresses=${addressesQuery}`;
+}
+
+function processUserDetails(userDetails: ApiResponse, results: { [key: Handle]: Address }): void {
+  for (const [address, data] of Object.entries(userDetails)) {
+    if (isValidUserData(data)) {
+      const checksumAddress = getAddress(address);
+      results[checksumAddress] = `${data[0].username}.fcast.id`;
+    }
+  }
+}
+
+function handleLookupError(e: any, addresses: Address[]): void {
+  if (!isSilencedError(e)) {
+    capture(e, { input: { addresses }, tags: { issue: 'lookup_addresses_failure' } });
+  }
+  throw new FetchError('No user found for this address.');
+}
+
+export async function resolveNames(handles: Handle[]): Promise<Record<Handle, Address>> {
+  const results: Record<Handle, Address> = {};
+  for (const handle of handles) {
+    const normalizedHandle = handle.replace('.fcast.id', '');
+    try {
+      const userDetails = await fetchUserDetailsByUsername(normalizedHandle);
+      if (userDetails && userDetails.eth_addresses) {
+        results[handle] = getAddress(userDetails.eth_addresses[0]);
+      }
+    } catch (e) {
+      console.error(`Error resolving name for handle ${handle}:`, e);
+    }
+  }
+  return results;
+}
+
+export async function lookupAddresses(addresses: Address[]): Promise<{ [key: Handle]: Address }> {
+  const results: { [key: Handle]: Address } = {};
+  try {
+    const url = buildLookupUrl(addresses);
+    const userDetails = await fetchData<ApiResponse>(url);
+    processUserDetails(userDetails, results);
+  } catch (e) {
+    handleLookupError(e, addresses);
+  }
+  return results;
+}

src/addressResolvers/index.ts

@@ -2,6 +2,7 @@ import * as ensResolver from './ens';
 import * as lensResolver from './lens';
 import * as unstoppableDomainResolver from './unstoppableDomains';
 import * as starknetResolver from './starknet';
+import * as farcasterResolver from './farcaster';
 import cache from './cache';
 import {
   Address,
@@ -13,7 +14,13 @@ import {
 } from './utils';
 import { timeAddressResolverResponse as timeResponse } from '../helpers/metrics';
 
-const RESOLVERS = [ensResolver, unstoppableDomainResolver, lensResolver, starknetResolver];
+const RESOLVERS = [
+  ensResolver,
+  unstoppableDomainResolver,
+  lensResolver,
+  starknetResolver,
+  farcasterResolver
+];
 const MAX_LOOKUP_ADDRESSES = 50;
 const MAX_RESOLVE_NAMES = 5;
 

test/integration/addressResolvers/farcaster.test.ts

@@ -0,0 +1,12 @@
+import { resolveNames, lookupAddresses } from '../../../src/addressResolvers/farcaster';
+import testAddressResolver from './helper';
+
+testAddressResolver({
+  name: 'Farcaster',
+  lookupAddresses,
+  resolveNames,
+  validAddress: '0xd1a8Dd23e356B9fAE27dF5DeF9ea025A602EC81e',
+  validDomain: 'codingsh.fcast.id',
+  blankAddress: '0x0000000000000000000000000000000000000000',
+  invalidDomains: ['domain.crypto', 'domain.eth', 'domain.com']
+});

yarn.lock

@@ -3503,6 +3503,11 @@ cssstyle@^2.3.0:
   dependencies:
     cssom "~0.3.6"
 
+data-uri-to-buffer@^4.0.0:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/data-uri-to-buffer/-/data-uri-to-buffer-4.0.1.tgz#d8feb2b2881e6a4f58c2e08acfd0e2834e26222e"
+  integrity sha512-0R9ikRb668HB7QDxT1vkpuUBtqc53YyAwMwGeUFKRojY/NWKvdZ+9UYtRfGmhqNbRkTSVpMbmyhXipFFv2cb/A==
+
 data-urls@^3.0.1:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/data-urls/-/data-urls-3.0.2.tgz#9cf24a477ae22bcef5cd5f6f0bfbc1d2d3be9143"
@@ -4082,6 +4087,14 @@ fb-watchman@^2.0.0:
   dependencies:
     bser "2.1.1"
 
+fetch-blob@^3.1.2, fetch-blob@^3.1.4:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/fetch-blob/-/fetch-blob-3.2.0.tgz#f09b8d4bbd45adc6f0c20b7e787e793e309dcce9"
+  integrity sha512-7yAQpD2UMJzLi1Dqv7qFYnPbaPx7ZfFK6PiIxQ4PfkGPyNyl2Ugx+a/umUonmKqjhM4DnfbMvdX6otXq83soQQ==
+  dependencies:
+    node-domexception "^1.0.0"
+    web-streams-polyfill "^3.0.3"
+
 figures@^3.0.0:
   version "3.2.0"
   resolved "https://registry.yarnpkg.com/figures/-/figures-3.2.0.tgz#625c18bd293c604dc4a8ddb2febf0c88341746af"
@@ -4162,6 +4175,13 @@ form-data@^4.0.0:
     combined-stream "^1.0.8"
     mime-types "^2.1.12"
 
+formdata-polyfill@^4.0.10:
+  version "4.0.10"
+  resolved "https://registry.yarnpkg.com/formdata-polyfill/-/formdata-polyfill-4.0.10.tgz#24807c31c9d402e002ab3d8c720144ceb8848423"
+  integrity sha512-buewHzMvYL29jdeQTVILecSaZKnt/RJWjoZCF5OW60Z67/GmSLBkOFM7qh1PI3zFNtJbaZL5eQu1vLfazOwj4g==
+  dependencies:
+    fetch-blob "^3.1.2"
+
 [email protected]:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/forwarded/-/forwarded-0.2.0.tgz#2269936428aad4c15c7ebe9779a84bf0b2a81811"
@@ -5522,13 +5542,23 @@ node-addon-api@^5.0.0:
   resolved "https://registry.yarnpkg.com/node-addon-api/-/node-addon-api-5.1.0.tgz#49da1ca055e109a23d537e9de43c09cca21eb762"
   integrity sha512-eh0GgfEkpnoWDq+VY8OyvYhFEzBk6jIYbRKdIlyTiAXIVJ8PyBaKb0rp7oDtoddbdoHWhq8wwr+XZ81F1rpNdA==
 
+
 node-fetch@^2.6.12, node-fetch@^2.6.7, node-fetch@^2.7.0, [email protected]:
   version "2.7.0"
   resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.7.0.tgz#d0f0fa6e3e2dc1d27efcd8ad99d550bda94d187d"
   integrity sha512-c4FRfUm/dbcWZ7U+1Wq0AwCyFL+3nt2bEw05wfxSz+DWpWsitgmSgYmy2dQdWyKC1694ELPqMs/YzUSNozLt8A==
   dependencies:
     whatwg-url "^5.0.0"
 
+node-fetch@^3.3.2:
+  version "3.3.2"
+  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-3.3.2.tgz#d1e889bacdf733b4ff3b2b243eb7a12866a0b78b"
+  integrity sha512-dRB78srN/l6gqWulah9SrxeYnxeddIG30+GOqK/9OlLVyLg3HPnr6SqOWTWOXKRwC2eGYCkZ59NNuSgvSrpgOA==
+  dependencies:
+    data-uri-to-buffer "^4.0.0"
+    fetch-blob "^3.1.4"
+    formdata-polyfill "^4.0.10"
+
 node-int64@^0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/node-int64/-/node-int64-0.4.0.tgz#87a9065cdb355d3182d8f94ce11188b825c68a3b"
@@ -6848,6 +6878,11 @@ walker@^1.0.8:
   dependencies:
     makeerror "1.0.12"
 
+web-streams-polyfill@^3.0.3:
+  version "3.3.3"
+  resolved "https://registry.yarnpkg.com/web-streams-polyfill/-/web-streams-polyfill-3.3.3.tgz#2073b91a2fdb1fbfbd401e7de0ac9f8214cecb4b"
+  integrity sha512-d2JWLCivmZYTSIoge9MsgFCZrt571BikcWGYkjC1khllbTeDlGqZ2D8vD8E/lJa8WGWbb7Plm8/XJYV7IJHZZw==
+
 webidl-conversions@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/webidl-conversions/-/webidl-conversions-3.0.1.tgz#24534275e2a7bc6be7bc86611cc16ae0a5654871"