fix: move package exports for react native

[timostroehlein]

Description of changes

Currently the react-native package exports are incorrectly order. The react-native package export should come before the require and import exports, since the condition names are resolved in order and default to ['require', 'react-native'].

Description of how you validated changes

I've only validated the changes by adjusting the exports using yarn patch in our repo.

Checklist

• PR description included

Checklist for repo maintainers

• Verify E2E tests for existing workflows are working as expected or add E2E tests for newly added workflows
• New source file paths included in this PR have been added to CODEOWNERS, if appropriate

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[HuiSF]

Hi @timostroehlein thank you for opening this PR, much appreciated. Have you actually encountered react-native bundle build issues with the existing exports settings?

Following the Metro documentation, unstable_conditionNames takes only effect when unstable_enablePackageExports is set to true. Do you currently enable this option?

[timostroehlein]

Hi @HuiSF, the issue actually isn't build related. The main issue was the inconsistency between the exports. Let me try to explain the main issue. The issue only happens if unstable_enablePackageExports is enabled and unstable_conditionNames is set to ['require', 'react-native'].

For example the @aws-amplify/core package doesn't define any package exports, but has a react-native export field at root exporting ts files. The order of the exports on root doesn't matter, so even with package exports enabled, metro will import from the react-native entry point, which is correct in this case.

On the other hand, most of the packages, e.g. the @aws-amplify/auth package does define package exports. Those exports are resolved in order, since the unstable_conditionNames in metro are set to ['require', 'react-native'] (order doesn't matter here), it will import from the require/cjs import. That isn't the expected behaviour, since we want to import from react-native.

In our case the Amplify config was undefined when calling signIn from @aws-amplify/auth, even though we called Amplify.configure, caused by both cjs and ts inconsistently referenced.