fix(formatter): use soft indent for empty objects in JSX spread attributes

[Boshen]

Summary

• Fix jsx/ignore/spread.js Prettier conformance test
• Empty objects with dangling comments inside JSX spread attributes now stay on one line if they fit
• For example, <div {...{/* comment */}} /> remains on one line, while var a = {/* comment */} still expands

Test plan

• cargo run -p oxc_prettier_conformance -- --filter "jsx/ignore/spread.js" passes
• cargo run -p oxc_prettier_conformance -- --filter "js/comments/dangling.js" still passes (no regression)
• cargo test -p oxc_formatter passes
• JS compatibility: 737/761 → 738/761 (+1)
• TS compatibility: 579/607 → 580/607 (+1)

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR fixes formatting of empty objects with dangling comments inside JSX spread attributes and JSX spread children. The change ensures that constructs like <div {...{/* comment */}} /> remain on one line if they fit, while maintaining the existing behavior of expanding empty objects with comments in other contexts (e.g., var a = {/* comment */} still expands to multiple lines).

Changes:

• Added is_inside_jsx_spread() method to detect when an object is inside a JSX spread attribute or JSX spread child
• Updated empty object formatting logic to use soft indent instead of block indent for JSX spread contexts
• Fixed one failing Prettier conformance test (jsx/ignore/spread.js)

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
crates/oxc_formatter/src/print/object_like.rs	Added is_inside_jsx_spread() method and conditional formatting logic for empty objects with dangling comments
tasks/prettier_conformance/snapshots/prettier.js.snap.md	Updated JS compatibility score from 737/761 to 738/761, removed jsx/ignore/spread.js from failed tests
tasks/prettier_conformance/snapshots/prettier.ts.snap.md	Updated TS compatibility score from 579/607 to 580/607, removed jsx/ignore/spread.js from failed tests

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[codspeed-hq]

Merging this PR will not alter performance

✅ 38 untouched benchmarks
⏩ 7 skipped benchmarks¹

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_{Comparing fix/formatter-jsx-spread-dangling-comments (d43e945) with main (fd2c792)}

Footnotes

1. 7 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. ↩

[Boshen]

Merge activity

• Jan 16, 10:16 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Jan 16, 10:16 AM UTC: Boshen added this pull request to the Graphite merge queue.
• Jan 16, 10:23 AM UTC: Merged by the Graphite merge queue.