fix: remove extra slash when constructing user storage url (#4702)

## Explanation

This PR solves the bug of adding extra slash when user storage url is
generated

## References

## Changelog

### `@metamask/profile-sync-controller`

- **FIXED**: remove extra slash when constructing user storage url

## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've highlighted breaking changes using the "BREAKING" category
above as appropriate

---------

Co-authored-by: Mathieu Artu <mathieu.artu@consensys.net>

packages/profile-sync-controller/src/controllers/user-storage/__fixtures__/mockResponses.ts

@@ -27,7 +27,7 @@ export const getMockUserStorageEndpoint = (
     return `${USER_STORAGE_ENDPOINT}/${path}`;
   }
 
-  return `${USER_STORAGE_ENDPOINT}${createEntryPath(
+  return `${USER_STORAGE_ENDPOINT}/${createEntryPath(
     path as UserStoragePathWithFeatureAndKey,
     MOCK_STORAGE_KEY,
   )}`;

packages/profile-sync-controller/src/controllers/user-storage/schema.test.ts

@@ -1,10 +1,25 @@
-import { getFeatureAndKeyFromPath, USER_STORAGE_SCHEMA } from './schema';
+import {
+  createEntryPath,
+  getFeatureAndKeyFromPath,
+  USER_STORAGE_SCHEMA,
+} from './schema';
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 type ErroneousUserStoragePath = any;
 
 describe('user-storage/schema.ts', () => {
   describe('getFeatureAndKeyFromPath', () => {
+    it('should correctly construct user storage url', () => {
+      expect(
+        createEntryPath(
+          'notifications.notificationSettings',
+          'dbdc994804e591f7bef6695e525543712358dd5c952bd257560b629887972588',
+        ),
+      ).toBe(
+        'notifications/2072257b71d53b6cb8e72bab8e801e3d66faa0d5e1b822c88af466127e5e763b',
+      );
+    });
+
     it('should throw error if the feature.key format is incorrect', () => {
       const path = 'feature/key';
       expect(() =>

packages/profile-sync-controller/src/controllers/user-storage/schema.ts

@@ -93,5 +93,5 @@ export function createEntryPath(
   const { feature, key } = getFeatureAndKeyFromPath(path);
   const hashedKey = createSHA256Hash(key + storageKey);
 
-  return `/${feature}/${hashedKey}`;
+  return `${feature}/${hashedKey}`;
 }

packages/profile-sync-controller/src/controllers/user-storage/services.ts

@@ -58,7 +58,7 @@ export async function getUserStorage(
     const { bearerToken, path, storageKey, nativeScryptCrypto } = opts;
 
     const encryptedPath = createEntryPath(path, storageKey);
-    const url = new URL(`${USER_STORAGE_ENDPOINT}${encryptedPath}`);
+    const url = new URL(`${USER_STORAGE_ENDPOINT}/${encryptedPath}`);
 
     const userStorageResponse = await fetch(url.toString(), {
       headers: {
@@ -172,7 +172,7 @@ export async function upsertUserStorage(
     nativeScryptCrypto,
   );
   const encryptedPath = createEntryPath(path, storageKey);
-  const url = new URL(`${USER_STORAGE_ENDPOINT}${encryptedPath}`);
+  const url = new URL(`${USER_STORAGE_ENDPOINT}/${encryptedPath}`);
 
   const res = await fetch(url.toString(), {
     method: 'PUT',