test(parse): add unit tests for readJsonBodyOption

[iborazzi]

Description

Adds unit test coverage for readJsonBodyOption in src/parse.ts.

Details

• Tests reading and parsing a valid JSON file.
• Tests error handling when the specified JSON file does not exist.
• Tests error handling when the file contains invalid JSON.

[ryanio]

Thanks, readJsonBodyOption was untested and now it is not.

This repo is a read-only mirror, so the tests are recreated in our internal monorepo with you credited as co-author. Two small changes on the way in: the file arrived with a UTF-8 BOM, which our format check rejects, and I moved the temp directory from a Date.now() suffix to mkdtempSync so two concurrent runs cannot collide on the same path.

Closing in favor of the internal change, which ships in the next release.