fix(nextjs): Support automatic instrumentation for app directory with custom page extensions

[ziyadkhalil]

This PR updates the regex and logic for detecting middleware, route handler, and server component files to support custom page extensions, such as middleware.custom.ts and route.custom.ts.

Changes Made

• Modified the isRouteHandler function to use a regex that matches custom page extensions for route handler files.
• Modified the isMiddlewareResource function to use a regex that matches custom page extensions for middleware files.
• Modified the isServerComponent function to use a regex that matches custom page extensions for server component files.
• modified hasGlobalErrorFile flag to account for custom page extensions

Testing

• Verified the updated regex matches route handlers and middleware files with standard and custom extensions.
• Added new cases for server loaders tests to cover route handler files
• Updated and passed all test cases.
• Added a duplicate e2e nextjs project with page extensions enabled and it passes all tests e2e(nextjs): add nextjs app dir project with page extensions #12864

Checklist

• Modified isRouteHandler function.
• Modified isMiddlewareResource function.
• Modified isServerComponent function.
• Modified hasGlobalErrorFile flag.
• Manual and automated testing completed.
• e2e tests e2e(nextjs): add nextjs app dir project with page extensions #12864

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Please review and provide feedback. Thank you!

[AbhiPrasad]

@ziyadkhalil thanks for the PR! Could you update an e2e test to validate this? https://github.com/getsentry/sentry-javascript/tree/develop/dev-packages/e2e-tests

[ziyadkhalil]

@ziyadkhalil thanks for the PR! Could you update an e2e test to validate this? https://github.com/getsentry/sentry-javascript/tree/develop/dev-packages/e2e-tests

@AbhiPrasad Sure! I'm not sure which test to update tho as to test this change we have to set the pageExtension option in next.config.js.
Should I add a new nextjs project under test applications with the page extension option set in next.config.js and have the same tests as nextjs-app-dir?

Thank you for the quick feedback!

[AbhiPrasad]

Sure! I'm not sure which test to update tho as to test this change we have to set the pageExtension option in next.config.js

Good question. I'll let the other sdk maintainers chime in here for this as I have no strong opinions

[ziyadkhalil]

@AbhiPrasad Great! I created another PR #12864 with the suggested solution and it was a great idea that made me notice that page extensions feature is not working for server components as well.
I updated this PR to enable instrumentation for server components as well.
It passes all the e2e tests in the other PR #12864

[lforst]

Thank you!

[lforst]

I checked and this is actually not true. It's just very uncommon because usually you have jsx in your pages.

[lforst]

I am gonna merge this so that this is off your plate @ziyadkhalil. I will add tests as a follow-up.