feat(semantic): add TS2309 error for export assignment with other exports

[sapphi-red]

Added TS2309 error check.

[sapphi-red]

• feat(parser): add TS1174 error for classes extending multiple base classes #15993
• feat(semantic): add TS2309 error for export assignment with other exports #15992 👈 (View in Graphite)
• main

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[codspeed-hq]

CodSpeed Performance Report

Merging #15992 will not alter performance

_{Comparing 11-20-feat_parser_add_ts2309_error_for_export_assignment_with_other_exports (3748cbb) with main (ef05957)}

Summary

✅ 42 untouched
⏩ 3 skipped¹

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[Copilot]

Pull request overview

This PR implements TypeScript error TS2309, which detects when an export = statement is used in a module that also contains other exported elements. This is a semantic error in TypeScript because export = (CommonJS-style export) is incompatible with ES6-style exports.

Key Changes:

• Added semantic check for TS2309 that reports errors when export = coexists with other exports in the same scope
• Improved test coverage with 15 previously failing test cases now passing (from 57.17% to 57.76%)
• Implemented recursive checking for nested TypeScript module declarations

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
crates/oxc_semantic/src/checker/typescript.rs	Implements the core logic for detecting export assignment conflicts, including helper functions for checking statements in programs and module declarations
crates/oxc_semantic/src/checker/mod.rs	Integrates the new check into the semantic analysis pipeline, calling it during Program node processing
tasks/coverage/snapshots/parser_typescript.snap	Updates test snapshots showing 15 additional negative test cases now correctly reporting TS2309 errors

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[Boshen]

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[graphite-app]

Merge activity

• Nov 24, 5:54 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Nov 25, 6:32 AM UTC: This pull request can not be added to the Graphite merge queue. Please try rebasing and resubmitting to merge when ready.
• Nov 25, 6:32 AM UTC: Graphite disabled "merge when ready" on this PR due to: a merge conflict with the target branch; resolve the conflict and try again..
• Nov 25, 6:32 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Nov 25, 6:33 AM UTC: This pull request can not be added to the Graphite merge queue. Please try rebasing and resubmitting to merge when ready.
• Nov 25, 6:33 AM UTC: Graphite disabled "merge when ready" on this PR due to: a merge conflict with the target branch; resolve the conflict and try again..
• Nov 25, 6:33 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.