fix: Fix eth_chainId not being resolved from cache when using EIP-1193 Provider

packages/connect-evm/CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Add `ConnectEvm.status` property which exposes the current `ConnectionStatus` ([#136](https://github.com/MetaMask/connect-monorepo/pull/136))
 
+### Fixed
+
+- Fix `eth_chainId` requests not being resolved from local cached state when using the EIP-1193 Provider `request()` method over the `MwpTransport` ([#124](https://github.com/MetaMask/connect-monorepo/pull/124))
+
 ## [0.2.0]
 
 ### Added

packages/connect-evm/src/connect.ts

@@ -36,6 +36,7 @@ import { getPermittedEthChainIds } from './utils/caip';
 import {
   isAccountsRequest,
   isAddChainRequest,
+  isChainIdRequest,
   isConnectRequest,
   isSwitchChainRequest,
   validSupportedChainsUrls,
@@ -633,6 +634,10 @@ export class MetamaskConnectEVM {
       return this.#provider.accounts;
     }
 
+    if (isChainIdRequest(request)) {
+      return this.#provider.selectedChainId;
+    }
+
     logger('Request not intercepted, forwarding to default handler', request);
     return Promise.resolve();
   }

packages/connect-evm/src/constants.ts

@@ -14,10 +14,13 @@ export const CONNECT_METHODS = [
 
 export const ACCOUNTS_METHODS = ['eth_accounts', 'eth_coinbase'];
 
+export const CHAIN_METHODS = ['eth_chainId'];
+
 export const INTERCEPTABLE_METHODS = [
   ...ACCOUNTS_METHODS,
   ...IGNORED_METHODS,
   ...CONNECT_METHODS,
+  ...CHAIN_METHODS,
   // These have bespoke handlers
   'wallet_revokePermissions',
   'wallet_switchEthereumChain',

packages/connect-evm/src/utils/type-guards.ts

@@ -61,6 +61,18 @@ export function isAccountsRequest(
   return req.method === 'eth_accounts' || req.method === 'eth_coinbase';
 }
 
+/**
+ * Type guard for generic eth_chainId request.
+ *
+ * @param req - The request object to check
+ * @returns True if the request is a eth_chainId request, false otherwise
+ */
+export function isChainIdRequest(
+  req: ProviderRequest,
+): req is Extract<ProviderRequest, { method: 'eth_chainId' }> {
+  return req.method === 'eth_chainId';
+}
+
 /**
  * Validates that all values in a Record are valid URLs.
  *