IE9+ not supported since 4.3.5 because of loupe

[marian-r]

The official website says Chai supports IE version 9 and above, however out tests started to fail in IE after upgrading Chai to version 4.3.5 or 4.3.6. Tests in IE throw a "Syntax Error" inside loupe. Would it be possible to remove this dependency or shall I rather open an issue against loupe to fix IE support?

Workaround: Downgrade Chai to 4.3.4.

[keithamus]

Thanks for reporting @marian-r. I've transferred this to loupe. If you could please provide more information that would be helpful.

[marian-r]

I have been digging into thee details of the issue and I have a feeling the cause is the following. When Chai requires the loupe library the es-module-aware tools (Webpack in my case) look at the package.json. Because loupe defines module property in package.json that takes precedence over the main property. It means the source files of loupe will get loaded in the browser. And because source files contain modern ES5+ syntax older browsers like IE throw errors.

There is a possible workaround for Webpack to let it look at the main property first:

resolve: {
  byDependency: {
    commonjs: {
      mainFields: ['browser', 'main']
    }
  }
}

However, it would be good to fix this in loupe in order for Chai to support older browsers out of the box. It could be fixed by setting browser field in package.json to the same value as main. I will prepare a PR for this.

[github-actions]

🎉 This issue has been resolved in version 2.3.2 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[github-actions]

🎉 This issue has been resolved in version 2.3.3 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀