Fixing Circular Dependency Issues in My Node.js + Express API Project

vedant kale — Thu, 23 Apr 2026 11:41:13 +0000

While working on a Node.js + Express backend project, I ran into a frustrating issue caused by circular dependencies. It wasn’t immediately obvious, but it led to unpredictable runtime behavior and made debugging unnecessarily difficult.

I was using barrel imports (index.ts files) inside the same module.
At first, this felt clean and organized. But under the hood, it introduced hidden circular dependencies.

Example

// fileA.ts
import { funcB } from "./index";

// fileB.ts
import { funcC } from "./index";

// fileC.ts
import { funcA } from "./index";

// index.ts (barrel file)
export * from "./fileA";
export * from "./fileB";
export * from "./fileC";

The problem is, this creates a dependency loop:

A → B → C → A

Because of how Node.js module loading works, some modules are not fully initialized when they are imported. This results in: undefined values, Hard-to-trace bugs

The fix

To Fix this, I refactored the structure to remove circular dependencies completely.

1. Removed barrel imports inside the same module, Instead of importing from `./index`, I switched to direct imports.

// fileA.ts
import { funcB } from "./fileB";

2. Used relative imports for internal dependencies

3. Kept barrel files only for external usage, Barrel files are still useful. just not internally in the same module/folder.

// modules/user/index.ts
export * from "./user.controller";
export * from "./user.service";
export * from "./user.routes";

// outside the module
import { createUser } from "@/modules/user";

Conclusion

No more circular dependency issues, Cleaner and more predictable module structure, Easier debugging and maintenance

Barrel imports are helpful for simplifying external imports, but using them inside the same module can introduce hidden circular dependencies.

Use direct relative imports internally , Use barrel files only for external access

This small change can save hours of debugging and make your codebase significantly more stable.

DEV Community: vedant kale