fix(parser): reject using / await using in a switch case / default clause

[sapphi-red]

using / await using directly nested within a case or default clause are now disallowed (rbuckton/ecma262#14). This PR implements this change.

Note that TypeScript does not disallow them yet (microsoft/TypeScript#62708) and the test failing in tasks/coverage/snapshots/parser_typescript.snap is caused by that.

[sapphi-red]

• fix(parser): reject using / await using in a switch case / default clause #15225 👈 (View in Graphite)
• fix(parser): reject using / await using in single statement contexts #15224
• fix(parser): reject trailing commas after rest elements in object patterns #15223
• fix(parser): reject async await => {} in scripts #15222
• fix(parser): reject yield and await in object destructing shorthand property parameters #15221
• fix(parser): reject for (let.something of ...) #15220
• fix(parser): reject invalid assignment operator in assignment targets #15219
• chore(tasks/coverage): exclude some parser babel test cases that are not relevant #15218
• main

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[codspeed-hq]

CodSpeed Performance Report

Merging #15225 will not alter performance

_{Comparing 11-02-fix_parser_reject_using___await_using_in_a_switch_case___default_clause (693d569) with main (8b14ec9)}

Summary

✅ 37 untouched

[Copilot]

Pull Request Overview

This PR implements validation to prevent using and await using declarations from appearing directly in bare case statements of switch statements, as per the ECMAScript specification. The parser now emits an error with a helpful suggestion to wrap such declarations in a block statement.

• Added syntax error detection for using/await using declarations in bare switch case statements
• Introduced new diagnostic error message with helpful guidance
• Updated test snapshots to reflect new validation behavior

Reviewed Changes

Copilot reviewed 4 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/oxc_parser/src/js/statement.rs	Adds validation logic to detect using declarations in bare switch cases
crates/oxc_parser/src/diagnostics.rs	Defines new error diagnostic for invalid using declarations in switch cases
tasks/transform_conformance/snapshots/babel.snap.md	Updates babel transform test results with new error messages
tasks/coverage/snapshots/parser_typescript.snap	Updates TypeScript parser test results with new validation
tasks/coverage/snapshots/parser_babel.snap	Updates Babel parser test results showing improved negative test coverage
tasks/coverage/snapshots/semantic_typescript.snap	Updates TypeScript semantic analysis results
tasks/coverage/snapshots/formatter_typescript.snap	Updates formatter test results
tasks/coverage/snapshots/estree_typescript.snap	Updates ESTree test results
crates/oxc_linter/src/snapshots/eslint_no_case_declarations.snap	Updates linter snapshot showing parser errors now take precedence

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[Boshen]

Need Test262 before we land.

[Boshen]

@sapphi-red can you remove this from the stack.

[Boshen]

Saw the title: tc39/test262#4498

[graphite-app]

Merge activity

• Nov 8, 10:27 AM UTC: Dunqing added this pull request to the Graphite merge queue.
• Nov 8, 10:35 AM UTC: Merged by the Graphite merge queue.

[Boshen]

Let's merge to avoid merge conflicts. Also because babel and acorn has implemented this.