How to Resolve Nodemon App Crash and File Change Wait


By squashlabs, Last Updated: March 27, 2024

How to Resolve Nodemon App Crash and File Change Wait

If you are encountering the error message “Javascript: [nodemon] app crashed – waiting for file changes before starting…” while using nodemon, it means that your application has crashed and nodemon is waiting for file changes before restarting the application. This error can occur due to various reasons, such as syntax errors, runtime errors, or issues with your code. In this answer, we will explore a few possible solutions to resolve this issue.

1. Check for Syntax Errors

One common cause of the “Javascript: [nodemon] app crashed – waiting for file changes before starting…” error is a syntax error in your code. It’s important to check your code for any syntax errors, such as missing or misplaced brackets, semicolons, or quotation marks. These syntax errors can cause the application to crash, resulting in the error message.

To check for syntax errors, you can use a code editor or an integrated development environment (IDE) that provides real-time syntax highlighting and error checking. This can help you identify and fix any syntax errors in your code before running the application with nodemon.

Related Article: 25 Handy Javascript Code Snippets for Everyday Use

2. Check for Runtime Errors

Another possible cause of the error message is a runtime error in your code. Runtime errors can occur when your code encounters an unexpected condition or tries to perform an invalid operation. These errors can cause the application to crash, leading to the “Javascript: [nodemon] app crashed – waiting for file changes before starting…” message.

To check for runtime errors, you can use debugging tools provided by your code editor or IDE. These tools allow you to set breakpoints in your code and inspect variables and their values during runtime. By stepping through your code and examining the state of your application, you can identify and fix any runtime errors that may be causing the crash.

3. Review Log Files

If you are unable to identify the cause of the crash by checking for syntax or runtime errors, you can review the log files generated by nodemon. Nodemon logs useful information about the crash, including the location of the error and the stack trace. By analyzing the log files, you can get insights into the specific error that caused the crash.

To review the log files, you can navigate to the directory where your application is located and look for the log file generated by nodemon. The log file is usually named “nodemon-debug.log” or “nodemon.log”. Open the log file in a text editor and search for any error messages or stack traces that may indicate the cause of the crash. Once you have identified the error, you can make the necessary changes to your code to fix it.

4. Check Dependencies and Versions

Sometimes, the “Javascript: [nodemon] app crashed – waiting for file changes before starting…” error can occur due to incompatible dependencies or outdated versions of libraries used in your application. It’s important to check the dependencies listed in your package.json file and ensure that they are compatible with each other.

To check the dependencies and versions, open the package.json file in your code editor and review the “dependencies” section. Make sure that all the dependencies are up to date and compatible with each other. You can use tools like npm or yarn to update the dependencies to their latest versions.

If you suspect that a specific dependency is causing the crash, you can try downgrading or upgrading its version to see if it resolves the issue. Keep in mind that changing dependencies may have other implications on the functionality of your application, so it’s important to thoroughly test your application after making any changes.

Related Article: Advanced DB Queries with Nodejs, Sequelize & Knex.js

5. Restart Nodemon and Clear Cache

If none of the above solutions work, you can try restarting nodemon and clearing its cache. Sometimes, nodemon may encounter issues that can be resolved by restarting it and clearing any cached data.

To restart nodemon, you can simply stop the nodemon process by pressing Ctrl+C in the terminal or command prompt where nodemon is running. Once the process is stopped, you can start nodemon again by running the command “nodemon” in the terminal.

To clear the nodemon cache, you can delete the “.nodemon” directory located in the root directory of your application. This directory contains the cached data used by nodemon to monitor file changes. Deleting this directory will force nodemon to rebuild its cache from scratch.

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