Resolving Dynamic Import Issues in webpack 5 with TypeScript for IE11

Discover how to fix dynamic import problems in `webpack 5` when targeting `IE11` with `TypeScript` and `Babel`. Learn the nuances of code imports and the potential benefits of downgrading to `webpack 4`.
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Troubleshooting Dynamic Imports with Webpack 5 in IE11

When developing applications using modern JavaScript, you might encounter scenarios where older browsers, such as Internet Explorer 11 (IE11), create compatibility challenges. This is particularly true when working with bundlers like webpack and languages like TypeScript. One common issue developers face is the failure of dynamic imports in their webpack 5 setup, especially when targeting IE11. Let's break down the problem and explore a solution that can save you time and frustration.

The Problem

You are working on a library that requires importing an external module built with webpack. Everything functions correctly in IE11 until you introduce dynamic imports. Although core-js is included where necessary, the project fails to build or run with dynamic imports. In contrast, using require for imports seems to resolve the issue but does not support magic comments, which can be detrimental to your build efficiency.

Key Configuration Code

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The Problematic Code

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Exploring Potential Solutions

After troubleshooting this issue, one notable solution emerged: consider downgrading to webpack 4. Surprisingly, reverting to an older version resolved the issue, allowing dynamic imports to function correctly without necessitating a rewrite of your entire codebase.

Why Downgrade Webpack?

While it may seem counterintuitive to downgrade a tool, here are some reasons why it worked in this case:

Compatibility: Webpack 4 may have better default settings or polyfills that are suitable for older browsers like IE11.

Resolved Bugs: It may be that a bug affecting dynamic imports has been introduced in webpack 5 that does not exist in version 4.

Additional Considerations

When switching between import and require:

Dynamic Imports with require: If it's necessary to use require, keep in mind that it won’t utilize magic comments for code splitting and optimization.

Loading Order: Ensure any dynamically loaded scripts do not execute before they are appended to the DOM, as timing can affect functionality.

Conclusion

Combining newer JavaScript features with older browsers such as IE11 can be challenging, especially when using modern tooling. If you experience failures with dynamic imports in webpack 5 targeting IE11, consider downgrading to webpack 4 as a temporary solution. Remember also to test your implementations thoroughly to ensure compatibility across all targeted environments.

In closing, this journey hopefully provides you insights into managing and mitigating similar issues in your own development work. Happy coding!