Import class in definition file (*d.ts)

Import class in definition file (*d.ts) - A Guide for Beginners 👨‍💻

Are you having trouble importing a class in a *d.ts file to extend the Express Session typings? Don't worry! This blog post will walk you through common issues and provide easy solutions to help you use your own class in a *d.ts file. Let's get started! 🚀

Understanding the Problem 🤔

The initial problem is that the import statement at the top of your *d.ts file is not working, and neither VS Code nor tsc (TypeScript compiler) is recognizing it. This can be frustrating, but we will address this issue together. 🤝

Solution 1: Check the File Path 📂

First, double-check that the file path to your class is correct in the import statement. Verify that the relative path matches the actual location of the class file. A small mistake in the file path can cause the import to fail. 🕵️‍♂️

For example, in the code snippet you provided, import { User } from "./models/user";, ensure that the file named "user.ts" containing the User class is located in the "models" folder at the same level as your *d.ts file. 📁

Solution 2: Use Triple Slash Reference Directive 🎯

If Solution 1 doesn't work, you can try using a triple slash reference directive instead of the import statement. Insert the following line at the beginning of your *d.ts file:

/// <reference path='models/user.ts'/>

Make sure to update the file path if necessary. This directive tells the TypeScript compiler to include the referenced file along with your *d.ts file during compilation. It should make the User class visible to the *d.ts file. 🔍

Solution 3: Enable Declaration File Generation 📝

In your edit, you mentioned that you set tsc to generate definition files during compilation, and you now have a "user.d.ts" file. This is a good progress! However, you mentioned that it is still not working after using the import statement.

To solve this, make sure that the generated "user.d.ts" file is located in the correct folder and is accessible by the TypeScript compiler when it encounters the import statement. Additionally, ensure that the declaration file is up-to-date and reflects the correct class definition.

Conclusion and Call-to-Action 🏁

By following the solutions outlined above, you should be able to import your own class in a *d.ts file successfully. Remember to check the file path, use the triple slash reference directive if needed, and ensure the declaration file generation is properly configured.

If you're still facing issues or have any questions, don't hesitate to reach out. Let's help each other in the comments below! 🙌

Have you encountered other TypeScript or JavaScript problems that you'd like us to address? Let us know! We're always looking for new topics to cover. Until then, happy coding! 💻✨