refactor: Typescript conversion of eth-accounts.js (#23504)

app/scripts/lib/rpc-method-middleware/handlers/eth-accounts.ts

@@ -0,0 +1,59 @@
+import type {
+  JsonRpcEngineEndCallback,
+  JsonRpcEngineNextCallback,
+} from 'json-rpc-engine';
+import type {
+  JsonRpcRequest,
+  JsonRpcParams,
+  PendingJsonRpcResponse,
+} from '@metamask/utils';
+import { MESSAGE_TYPE } from '../../../../../shared/constants/app';
+import { AccountAddress } from '../../../controllers/account-order';
+import { HandlerWrapper } from './types';
+
+type EthAccountsHandlerOptions = {
+  getAccounts: () => Promise<AccountAddress[]>;
+};
+
+type EthAccountsConstraint<Params extends JsonRpcParams = JsonRpcParams> = {
+  implementation: (
+    _req: JsonRpcRequest<Params>,
+    res: PendingJsonRpcResponse<AccountAddress[]>,
+    _next: JsonRpcEngineNextCallback,
+    end: JsonRpcEngineEndCallback,
+    { getAccounts }: EthAccountsHandlerOptions,
+  ) => Promise<void>;
+} & HandlerWrapper;
+
+/**
+ * A wrapper for `eth_accounts` that returns an empty array when permission is denied.
+ */
+const ethAccounts = {
+  methodNames: [MESSAGE_TYPE.ETH_ACCOUNTS],
+  implementation: ethAccountsHandler,
+  hookNames: {
+    getAccounts: true,
+  },
+} satisfies EthAccountsConstraint;
+export default ethAccounts;
+
+/**
+ *
+ * @param _req - The JSON-RPC request object.
+ * @param res - The JSON-RPC response object.
+ * @param _next - The json-rpc-engine 'next' callback.
+ * @param end - The json-rpc-engine 'end' callback.
+ * @param options - The RPC method hooks.
+ * @param options.getAccounts - Gets the accounts for the requesting
+ * origin.
+ */
+async function ethAccountsHandler<Params extends JsonRpcParams = JsonRpcParams>(
+  _req: JsonRpcRequest<Params>,
+  res: PendingJsonRpcResponse<AccountAddress[]>,
+  _next: JsonRpcEngineNextCallback,
+  end: JsonRpcEngineEndCallback,
+  { getAccounts }: EthAccountsHandlerOptions,
+): Promise<void> {
+  res.result = await getAccounts();
+  return end();
+}

app/scripts/lib/rpc-method-middleware/handlers/types.ts

@@ -0,0 +1,6 @@
+import { MessageType } from '../../../../../shared/constants/app';
+
+export type HandlerWrapper = {
+  methodNames: [MessageType] | MessageType[];
+  hookNames: Record<string, boolean>;
+};

shared/constants/app.ts

@@ -65,6 +65,8 @@ export const MESSAGE_TYPE = {
   ///: END:ONLY_INCLUDE_IF
 } as const;
 
+export type MessageType = (typeof MESSAGE_TYPE)[keyof typeof MESSAGE_TYPE];
+
 ///: BEGIN:ONLY_INCLUDE_IF(keyring-snaps)
 export const SNAP_MANAGE_ACCOUNTS_CONFIRMATION_TYPES = {
   confirmAccountCreation: 'snap_manageAccounts:confirmAccountCreation',