From a814748dfb39dc70302becbca95c19606e3bab8e Mon Sep 17 00:00:00 2001
From: vincentwschau <99756290+vincentwschau@users.noreply.github.com>
Date: Fri, 13 Oct 2023 15:35:37 -0400
Subject: [PATCH] [IND-445] Add legal copy for websocket error messages for
 blocked addresses. (#622)

---
 .../socks/__tests__/lib/subscriptions.test.ts | 35 ++++++++++++++++++-
 indexer/services/socks/src/lib/errors.ts      |  9 +++++
 .../services/socks/src/lib/subscription.ts    | 16 +++++++--
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/indexer/services/socks/__tests__/lib/subscriptions.test.ts b/indexer/services/socks/__tests__/lib/subscriptions.test.ts
index 5a9d677d64..8cd3711ff1 100644
--- a/indexer/services/socks/__tests__/lib/subscriptions.test.ts
+++ b/indexer/services/socks/__tests__/lib/subscriptions.test.ts
@@ -8,7 +8,8 @@ import {
 } from '@dydxprotocol-indexer/postgres';
 import { btcTicker, invalidChannel, invalidTicker } from '../constants';
 import { axiosRequest } from '../../src/lib/axios';
-import { makeAxiosSafeServerError } from '@dydxprotocol-indexer/base';
+import { AxiosSafeServerError, makeAxiosSafeServerError } from '@dydxprotocol-indexer/base';
+import { BlockedError } from '../../src/lib/errors';
 
 jest.mock('ws');
 jest.mock('../../src/helpers/wss');
@@ -217,6 +218,38 @@ describe('Subscriptions', () => {
       expect(subscriptions.subscriptionLists[connectionId]).toBeUndefined();
     });
 
+    it('sends blocked error message if initial message request fails with 403', async () => {
+      const expectedError: BlockedError = new BlockedError();
+      axiosRequestMock.mockImplementation(
+        () => {
+          throw new AxiosSafeServerError({
+            data: {},
+            status: 403,
+            statusText: '',
+          }, {});
+        },
+      );
+      await subscriptions.subscribe(
+        mockWs,
+        Channel.V4_ACCOUNTS,
+        connectionId,
+        initialMsgId,
+        mockSubaccountId,
+      );
+
+      expect(sendMessageMock).toHaveBeenCalledTimes(1);
+      expect(sendMessageMock).toHaveBeenCalledWith(
+        mockWs,
+        connectionId,
+        expect.objectContaining({
+          connection_id: connectionId,
+          type: 'error',
+          message: expectedError.message,
+        }));
+      expect(subscriptions.subscriptions[Channel.V4_ACCOUNTS]).toBeUndefined();
+      expect(subscriptions.subscriptionLists[connectionId]).toBeUndefined();
+    });
+
     it('sends empty contents if initial message request fails with 404 for accounts', async () => {
       axiosRequestMock.mockImplementation(() => {
         return Promise.reject(makeAxiosSafeServerError(404, '', ''));
diff --git a/indexer/services/socks/src/lib/errors.ts b/indexer/services/socks/src/lib/errors.ts
index 58769b19ee..7501de2723 100644
--- a/indexer/services/socks/src/lib/errors.ts
+++ b/indexer/services/socks/src/lib/errors.ts
@@ -1,3 +1,5 @@
+import { INDEXER_COMPLIANCE_BLOCKED_PAYLOAD } from '@dydxprotocol-indexer/compliance';
+
 export class InvalidForwardMessageError extends Error {
   constructor(message: string) {
     super(`Invalid forwarded message. Error: ${message}.`);
@@ -18,3 +20,10 @@ export class InvalidTopicError extends Error {
     this.name = 'InvalidTopicError';
   }
 }
+
+export class BlockedError extends Error {
+  constructor() {
+    super(INDEXER_COMPLIANCE_BLOCKED_PAYLOAD);
+    this.name = 'BlockedError';
+  }
+}
diff --git a/indexer/services/socks/src/lib/subscription.ts b/indexer/services/socks/src/lib/subscription.ts
index 1da7eeea35..71a8a02ecb 100644
--- a/indexer/services/socks/src/lib/subscription.ts
+++ b/indexer/services/socks/src/lib/subscription.ts
@@ -18,7 +18,7 @@ import {
 } from '../types';
 import { axiosRequest } from './axios';
 import { V4_MARKETS_ID, WS_CLOSE_CODE_POLICY_VIOLATION } from './constants';
-import { InvalidChannelError } from './errors';
+import { BlockedError, InvalidChannelError } from './errors';
 import { RateLimiter } from './rate-limit';
 
 const COMLINK_URL: string = `http://${config.COMLINK_URL}`;
@@ -140,11 +140,18 @@ export class Subscriptions {
         id,
       });
 
+      // For blocked errors add the erorr message into the error message sent in the websocket
+      // connection
+      let errorMsg: string = `Internal error, could not fetch data for subscription: ${channel}.`;
+      if (error instanceof BlockedError) {
+        errorMsg = error.message;
+      }
+
       sendMessage(
         ws,
         connectionId,
         createErrorMessage(
-          `Internal error, could not fetch data for subscription: ${channel}`,
+          errorMsg,
           connectionId,
           messageId,
         ),
@@ -521,6 +528,11 @@ export class Subscriptions {
       if (error instanceof AxiosSafeServerError && (error as AxiosSafeServerError).status === 404) {
         return EMPTY_INITIAL_RESPONSE;
       }
+      // 403 indicates a blocked address. Throw a specific error for blocked addresses with a
+      // specific error message detailing why the subscription failed due to a blocked address.
+      if (error instanceof AxiosSafeServerError && (error as AxiosSafeServerError).status === 403) {
+        throw new BlockedError();
+      }
       throw error;
     }
   }