VFile Property Checker

vfile-is is a utility package within the unified/vfile ecosystem, designed to facilitate checking properties of `vfile` objects. It allows developers to assert whether a virtual file matches specific criteria, supporting a range of tests including glob patterns against `file.path`, direct string matches against `file.basename` or `file.extname`, custom predicate functions, or object-based comparisons against various `vfile` fields like `stem`, `extname`, or `basename`. The current stable version is 3.0.0, which mandates Node.js 16 or newer and is ESM-only. The package maintains a steady release cadence, often aligning with updates to the core `vfile` library. Its key differentiators include its integration with the `vfile` standard, offering a streamlined API (`is` and `convert`) for robust and composable file testing, which helps in building unified-based tools by providing a consistent way to filter or categorize files.