TS2307 Cannot Find Module From A Dynamic Import Inside A Doc Comment In A Js File

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Introduction

When working with TypeScript and Deno, you may encounter the error TS2307, which indicates that the compiler cannot find a module. This error can be particularly frustrating when it occurs in a dynamic import inside a doc comment in a JavaScript file. In this article, we will explore the issue of TS2307 in Deno and provide a solution to resolve it.

Understanding the Issue

The error TS2307 occurs when the TypeScript compiler is unable to find a module that is being imported dynamically. In the case of the provided example, the issue arises from a dynamic import inside a doc comment in a JavaScript file. The doc comment contains a dynamic import statement that attempts to import a module from a specific path.

/**
 * ...
 *     <LazyMotion features={() => import('./path/to/domAnimation')}>
 * ...
 * /

When the TypeScript compiler encounters this dynamic import statement, it throws an error TS2307, indicating that it cannot find the module.

Minimal Repro.js

To reproduce the issue, we can create a minimal repro.js file that contains a dynamic import statement inside a doc comment.

/** {import('./missing')} */

When we run the Deno type checker on this file, we get the following error:

$ deno check repro.js 
Check file:///.../repro.js
TS2307 [ERROR]: Cannot find module 'file:///.../missing'.
    at file:///.../repro.js:1:13

error: Type checking failed.

Why Does This Happen?

The reason why this error occurs in Deno but not in the TypeScript compiler is due to the way Deno handles dynamic imports. Deno uses a different approach to resolve dynamic imports, which can lead to this error.

Solution

To resolve this issue, we can use the --allowJs flag when running the Deno type checker. This flag tells Deno to allow JavaScript files to be checked for type errors.

$ deno check --allowJs repro.js

Alternatively, we can add the // @ts-nocheck: ignored comment at the top of the repro.js file to ignore the type checking error.

// @ts-nocheck: ignored
/** {import('./missing')} */

However, it's worth noting that adding // @ts-nocheck: ignored is not a recommended solution, as it can lead to type errors being ignored in other parts of the codebase.

Conclusion

In conclusion, the error TS2307 in Deno can occur when a dynamic import is used inside a doc comment in a JavaScript file. To resolve this issue, we can use the --allowJs flag when running the Deno type checker or add the // @ts-nocheck: ignored comment at the top of the file. However, it's recommended to use the --allowJs flag as it provides a more accurate and reliable solution.

Additional Information

For more information on the Deno type checker and its flags, please refer to the Deno documentation.

Related Issues

If you are experiencing similar issues with the compiler, you can refer to the following issues:

References

Example Use Cases

Here are some example use cases where the solution to this issue can be applied:

  • Dynamic imports in JavaScript files
  • Doc comments with dynamic imports
  • TypeScript projects with Deno as the runtime environment

Q: What is the TS2307 error?

A: The TS2307 error is a type error that occurs when the TypeScript compiler is unable to find a module that is being imported dynamically.

Q: Why does the TS2307 error occur in Deno but not in the TypeScript compiler?

A: The reason why the TS2307 error occurs in Deno but not in the TypeScript compiler is due to the way Deno handles dynamic imports. Deno uses a different approach to resolve dynamic imports, which can lead to this error.

Q: How can I reproduce the TS2307 error?

A: To reproduce the TS2307 error, you can create a minimal repro.js file that contains a dynamic import statement inside a doc comment.

/** {import('./missing')} */

Q: What is the solution to the TS2307 error?

A: The solution to the TS2307 error is to use the --allowJs flag when running the Deno type checker or add the // @ts-nocheck: ignored comment at the top of the file.

Q: Why is using the --allowJs flag a better solution than adding // @ts-nocheck: ignored?

A: Using the --allowJs flag is a better solution than adding // @ts-nocheck: ignored because it provides a more accurate and reliable solution. Adding // @ts-nocheck: ignored can lead to type errors being ignored in other parts of the codebase.

Q: Can I use the --allowJs flag with other Deno flags?

A: Yes, you can use the --allowJs flag with other Deno flags. For example, you can use the --allowJs flag with the --check flag to check the types of JavaScript files.

$ deno check --allowJs repro.js

Q: What are some common use cases for dynamic imports in JavaScript files?

A: Some common use cases for dynamic imports in JavaScript files include:

  • Loading modules dynamically based on user input or configuration
  • Loading modules dynamically based on the environment or platform
  • Loading modules dynamically to improve performance or reduce memory usage

Q: How can I ensure that my TypeScript projects with Deno as the runtime environment are type-safe and free from errors?

A: To ensure that your TypeScript projects with Deno as the runtime environment are type-safe and free from errors, you can:

  • Use the --allowJs flag when running the Deno type checker
  • Add the // @ts-nocheck: ignored comment at the top of the file (although this is not recommended)
  • Use a linter or code analysis tool to catch type errors and other issues
  • Write unit tests and integration tests to ensure that your code is working as expected

Q: What are some resources for learning more about Deno and TypeScript?

A: Some resources for learning more about Deno and TypeScript include:

  • The Deno documentation
  • The TypeScript documentation
  • The Deno and TypeScript communities on GitHub and Stack Overflow
  • Online courses and tutorials on Deno and TypeScript
  • Books and articles on Deno and TypeScript

By following these best practices and resources, you can ensure that your TypeScript projects with Deno as the runtime environment are type-safe and free from errors.