add coverage for inverse futures private getter endpoints, migrate private getter methods to base class

src/util/node-support.ts

@@ -1,7 +1,8 @@
 import { createHmac } from 'crypto';
 
-export async function signMessage(message: string, secret: string): Promise<string> {
-  return createHmac('sha256', secret)
-    .update(message)
-    .digest('hex');
-};
+export async function signMessage(
+  message: string,
+  secret: string
+): Promise<string> {
+  return createHmac('sha256', secret).update(message).digest('hex');
+}

src/util/requestUtils.ts

@@ -59,11 +59,18 @@ export function getRestBaseUrl(
 }
 
 export function isPublicEndpoint(endpoint: string): boolean {
-  if (endpoint.startsWith('v2/public')) {
-    return true;
-  }
-  if (endpoint.startsWith('public/linear')) {
-    return true;
+  const publicPrefixes = [
+    'v2/public',
+    'public/linear',
+    'spot/quote/v1',
+    'spot/v1/symbols',
+    'spot/v1/time',
+  ];
+
+  for (const prefix of publicPrefixes) {
+    if (endpoint.startsWith(prefix)) {
+      return true;
+    }
   }
   return false;
 }