FileHandle 类

而是，始终显式关闭 FileHandle。 Node.js 将来可能会更改此行为。

A FileHandle object is a wrapper for a numeric file descriptor. Instances of FileHandle are distinct from numeric file descriptors in that they provide an object oriented API for working with files.

If a FileHandle is not closed using the filehandle.close() method, it might automatically close the file descriptor and will emit a process warning, thereby helping to prevent memory leaks. Please do not rely on this behavior because it is unreliable and the file may not be closed. Instead, always explicitly close FileHandles. Node.js may change this behavior in the future.

Instances of the FileHandle object are created internally by the fsPromises.open() method.

Unlike the callback-based API (fs.fstat(), fs.fchown(), fs.fchmod(), and so on), a numeric file descriptor is not used by the promise-based API. Instead, the promise-based API uses the FileHandle class in order to help avoid accidental leaking of unclosed file descriptors after a Promise is resolved or rejected.