Input

export const A = () => (
  <div>
    {someLongConditionA &&
      someLongConditionB && ( // a much longer explanatory comment that clearly pushes the collapsed line beyond the 120 character print width
        <span>content</span>
      )}
  </div>
);

Config

{
  "printWidth": 120
}

Oxfmt output

export const A = () => (
  <div>
    {someLongConditionA && someLongConditionB && ( // a much longer explanatory comment that clearly pushes the collapsed line beyond the 120 character print width
      <span>content</span>
    )}
  </div>
);

The {...} line is 163 characters with printWidth: 120.

Oxfmt playground link

https://playground.oxc.rs/?t=formatter&formatterPanels=output,prettier&code=export%20const%20A%20%3D%20()%20%3D%3E%20(%0A%20%20%3Cdiv%3E%0A%20%20%20%20%7BsomeLongConditionA%20%26%26%0A%20%20%20%20%20%20someLongConditionB%20%26%26%20(%20%2F%2F%20a%20much%20longer%20explanatory%20comment%20that%20clearly%20pushes%20the%20collapsed%20line%20beyond%20the%20120%20character%20print%20width%0A%20%20%20%20%20%20%20%20%3Cspan%3Econtent%3C%2Fspan%3E%0A%20%20%20%20%20%20)%7D%0A%20%20%3C%2Fdiv%3E%0A)%3B

(Note: set printWidth to 120 in the playground's Configure Options panel to reproduce)

Prettier output

export const A = () => (
  <div>
    {someLongConditionA &&
      someLongConditionB && ( // a much longer explanatory comment that clearly pushes the collapsed line beyond the 120 character print width
        <span>content</span>
      )}
  </div>
);

Additional notes

When a JSX expression uses an && chain whose final operand is a parenthesized JSX element, and the ( carries a trailing inline // comment, oxfmt collapses the entire && chain onto a single line — even when the resulting line clearly exceeds printWidth. Prettier breaks the chain before the && so the line fits. The trailing inline comment after ( appears to not be counted toward the line-length budget.

• Removing the trailing // comment after ( makes oxfmt produce the expected (broken) output, so the comment is the trigger.
• Replacing the // comment with a block /* */ comment behaves the same way (collapsed past printWidth).
• Related but not identical to formatter: JSX expression child unnecessarily expanded across 3 lines when it fits within printWidth #21916 (JSX expression child unnecessarily expanded across 3 lines — this is the inverse: collapsed when it should be expanded) and formatter: JSX text/expression line wrapping differs from Prettier (inserts {" "} instead of breaking at operator) #21907 (JSX text/expression wrapping inserts {" "} instead of breaking at operator).

Tested against oxfmt 0.47.0 and prettier 3.8.3.