Why Does Your Node.js Project Fail on Linux but Works on Windows?

Developers often encounter an issue where their Node.js project runs smoothly on Windows but fails on Linux. One common culprit is case sensitivity in file and folder names. This issue is especially problematic in CI/CD environments using Jenkins and Docker on Linux-based production servers.

In this article, we’ll explore why this happens, how it affects Jenkins and Docker-based deployments, and what steps you can take to resolve it.

Understanding the Issue: Windows vs. Linux File Systems

Windows (Case-Insensitive)

• Windows file systems (NTFS, FAT32) are case-insensitive.
  
  

• require("config.js") will work even if the file is named Config.js.
  
  

• The system does not differentiate between MyComponent.js and mycomponent.js.
  
  

Linux (Case-Sensitive)

• Linux file systems (ext4, XFS) are case-sensitive.
  
  

• require("config.js") will fail if the actual file name is Config.js.
  
  

• It treats MyComponent.js and mycomponent.js as two different files.
  
  

This difference can cause unexpected failures when deploying applications from Windows to Linux servers.

How It Affects Jenkins and Docker-Based Deployments

1. Jenkins Build Failure

Jenkins runs on Linux in most production environments. When Jenkins fetches your Node.js project from Gitea, GitHub, or any source control, it retains the case-sensitive structure of filenames. If your code references import MyModule from "./mymodule.js" but the actual file is MyModule.js, the build will fail with Module not found errors.

2. Docker Container Deployment Failure

Docker uses the Linux filesystem inside containers, even when running on Windows (in WSL2 mode). This means:

• A case mismatch that doesn’t break on Windows will break inside a Linux-based Docker container.
  
  

• If your Node.js app has a mismatch, it may work during local development on Windows but fail in production.
  
  

Step-by-Step Fix for Case-Sensitivity Issues

Step 1: Identify Case Mismatches in Your Code

Run the following command in your project directory:

find . -type f | sort

This lists all files in case-sensitive order, helping you spot mismatches.

You can also use:

grep -ri "require(" ./src  # Check for require/import mismatches

Step 2: Use a Case-Sensitive Linter

Add the following rule to ESLint:

"rules": {

  "import/no-unresolved": "error"

}

Then, run:

npx eslint .

This will flag incorrect imports.

Step 3: Enforce Naming Conventions in Git

Git tracks file names in a case-sensitive manner. However, if a file was committed with the wrong case, it might not be detected as a change. Fix it using:

git config core.ignorecase false

Then, rename the file properly:

git mv OldFileName.js temp.js

git mv temp.js CorrectFileName.js

Commit and push the changes:

git commit -am "Fix case-sensitive filename issues"

git push origin main

Step 4: Test on a Linux Environment Before Deploying

If you're developing on Windows, always test your build on a Linux machine or WSL2 before pushing to Jenkins/Docker:

docker run --rm -v "$PWD":/app -w /app node:20 npm run build

This helps catch case-related issues before deployment.

Best Practices for Node.js Projects to Avoid Case Sensitivity Issues

1. Maintain Consistent Naming Conventions

Use lowercase filenames for all files and folders (e.g., userController.js → user-controller.js).

Avoid mixing case in filenames and imports:

import UserService from "./UserService";  // ❌ Bad (will fail on Linux)

import UserService from "./user-service"; // ✅ Good

2. Enforce Case Sensitivity in Git

Git on Windows ignores case by default. To prevent case-related issues, force case sensitivity in Git:

git config --global core.ignorecase false

If a file was committed with the wrong case, rename it properly:

git mv OldFileName.js temp.js

git mv temp.js correct-file-name.js

git commit -am "Fix case-sensitive filename issues"

git push origin main

3. Use a Linter to Detect Case Issues

Add ESLint rules to flag incorrect imports:

"rules": {

  "import/no-unresolved": "error"

}

Run ESLint to detect mismatches:

npx eslint .

4. Test on a Linux Environment Before Deployment

If developing on Windows, always test on Linux before deploying:

docker run --rm -v "$PWD":/app -w /app node:20 npm run build

Alternatively, use WSL2 (Windows Subsystem for Linux) for development.

5. Use Path Module Instead of Hardcoded Paths

Avoid hardcoded file paths and use Node.js path module for cross-platform compatibility:

const path = require("path");

const filePath = path.join(__dirname, "config.json");

6. Set Up CI/CD Checks

Run tests on both Windows and Linux environments in CI/CD pipelines:

jobs:

  build:

    runs-on: ubuntu-latest

    steps:

      - name: Checkout Code

        uses: actions/checkout@v2

      - name: Install Dependencies

        run: npm install

      - name: Run Tests

        run: npm test

Conclusion

Merits of Fixing Case-Sensitivity Issues

✔ Ensures smooth deployment across all environments. ✔ Prevents unexpected build failures in Jenkins & Docker. ✔ Saves debugging time in production. ✔ Improves consistency in team collaboration.

Demerits & Risks

❌ If not handled properly, renaming files can cause Git merge conflicts. ❌ In large codebases, fixing these issues manually can be time-consuming.

Caution

Always test changes before deploying to production. Incorrect fixes might introduce new bugs or break dependencies.

By following these best practices, you can ensure a seamless development and deployment workflow between Windows and Linux environments.