feat(parser): improve error message for using declarations with export

[sapphi-red]

Add a better error message for export using x = something and export await using x = something.

[sapphi-red]

• feat(parser): improve error message for using declarations with export #15266 👈 (View in Graphite)
• main

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[Copilot]

Pull Request Overview

This PR improves error messaging for exported using declarations in TypeScript/JavaScript. Instead of reporting a generic "Unexpected token" error when export using or export await using is encountered, it now provides a specific error message explaining that using declarations cannot be exported directly, along with helpful guidance on how to properly export them.

• Replaced generic "Unexpected token" errors with specific "Using declarations cannot be exported directly" error messages
• Added helpful error messages suggesting to split the export and declaration into separate statements
• Made is_using_declaration() function public to enable reuse across modules

Reviewed Changes

Copilot reviewed 3 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/oxc_parser/src/diagnostics.rs	Added new using_declaration_cannot_be_exported diagnostic function with helpful message
crates/oxc_parser/src/ts/statement.rs	Added handling for export using and export await using cases to emit the new specific error
crates/oxc_parser/src/js/statement.rs	Changed visibility of is_using_declaration() from private to public
tasks/coverage/snapshots/parser_typescript.snap	Updated test snapshots with improved error messages
tasks/coverage/snapshots/parser_babel.snap	Updated test snapshots with improved error messages

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[codspeed-hq]

CodSpeed Performance Report

Merging #15266 will not alter performance

_{Comparing 11-03-feat_parser_improve_error_message_for_using_declarations_with_export_ (d3e8f21) with main (d6996d0)}

Summary

✅ 37 untouched

[Boshen]

Merge activity

• Nov 4, 1:06 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Nov 4, 1:06 PM UTC: Boshen added this pull request to the Graphite merge queue.
• Nov 4, 1:12 PM UTC: Merged by the Graphite merge queue.