Resolving the Cannot read properties of undefined (reading 'sendMessage') Error in Chrome Extensions

---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Chrome Extension with injected Javascript - Cannot read properties of undefined (reading 'sendMessage')

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Troubleshooting the Cannot read properties of undefined (reading 'sendMessage') Error in Chrome Extensions

If you're developing a Chrome extension and encountered the frustrating error Cannot read properties of undefined (reading 'sendMessage'), you're not alone. This error often occurs when trying to send messages to the background script from an injected script, and is commonly associated with the use of Chrome's messaging system. In this guide, we'll walk through why this issue arises and how to effectively resolve it.

Understanding the Problem

Key Components Involved

Analyzing Your Scripts

Here’s a concise breakdown of your scripts to identify potential issues:

[[See Video to Reveal this Text or Code Snippet]]

This listens for incoming messages correctly.

[[See Video to Reveal this Text or Code Snippet]]

[[See Video to Reveal this Text or Code Snippet]]

Solution: Correctly Injecting the Script

1. Authorization and Permissions:

2. Use Correct Injection Method:

Recommended Steps:

[[See Video to Reveal this Text or Code Snippet]]

3. Handling Promises Correctly:

Example for Clarity:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By restructuring how you inject your scripts and ensuring you have the correct permissions, you should be able to resolve the Cannot read properties of undefined (reading 'sendMessage') error without complications. Embrace declarative injections for cleaner code and a better understanding of the context in which your scripts run.

If this guide was helpful, feel free to share your success stories or challenges you’ve faced while developing your Chrome extensions in the comments below!