Refactored code in controllers/bulk.js

[Mehulantony]

Included 4 helper functions to reduce duplications and improve maintainability:

1. setJsonHeaders - Standardizes JSON response headers by centralizing the "Content-Type" setting. Ensures consistent formatting in bulkCreate and bulkUpdate
2. fail - A reusable helper function to generate and forward Express errors.
3. requireNonEmptyArrayBody - Ensures the body is a non-empty array
4. isValidJsonObject - Ensures each item is a valid non-array JSON object.

In general, this problem is fixed by adding a rate-limiting middleware to the affected routes so that each client (or IP) can only make a bounded number of requests over a time window. For Express applications, a standard solution is the express-rate-limit package, configured with sensible limits for the specific endpoints.

For this file, the best minimal fix is to import express-rate-limit, define a limiter specifically for search endpoints, and apply it to both POST routes (/ and /phrase) without changing the existing handler behavior. Concretely:

• Add an import/require for express-rate-limit at the top of routes/search.js.
• Define a searchLimiter instance with appropriate windowMs and max values (for example, 100 requests per 15 minutes per IP, mirroring the example from the background).
• Apply searchLimiter to the route definitions, e.g., router.route('/').post(searchLimiter, controller.searchAsWords), and the same for /phrase.

All changes stay within routes/search.js. No changes to controller or other files are assumed or required.

In general, the problem is fixed by introducing rate limiting middleware in front of any route handler that performs expensive operations like database queries. In Express, this is commonly done using a middleware such as express-rate-limit, configured with an appropriate window length and maximum request count, and then attached either to the whole app, a router, or specific routes.

For this code, the least intrusive and clearest fix is to add a rate limiter specifically for the search routes in routes/search.js. Because we can only modify this file, we will: (1) import express-rate-limit; (2) define a limiter instance with reasonable defaults (for example, a 15-minute window and 100 requests per IP, matching the background example); and (3) apply that limiter to the relevant routes. The most straightforward way, without changing existing behavior of handlers, is to apply router.use(searchLimiter) so it protects both '/' and '/phrase' search routes, or to apply it individually to each route definition. Applying it to the whole router has the benefit of also covering any future search routes defined here without further changes.

Concretely:

• At the top of routes/search.js, after the existing imports, add import rateLimit from 'express-rate-limit'.
• Define a const searchLimiter = rateLimit({ ... }) with configuration comments so its behavior is clear and can be tuned later.
• Attach router.use(searchLimiter) after the limiter definition and before the route definitions, so all routes in this router are rate-limited.
  This preserves all existing route behavior (methods, status codes, error handling) while adding protection against abuse.

[joeljoby02]

• The new commits are well structured.
• The changes introduced here improve correctness and robustness, especially around input validation.
• One area to consider for future improvement is reducing duplicated validation logic across bulk operations. While the current implementation is clear, extracting shared checks into a common helper would improve maintainability and reduce the risk of inconsistencies as additional bulk features are added.

[joeljoby02]

Could further enhance the error message by pointing to which object caused the error through indexing or any other valid method