No explicit file lock release when write() throws an exception #153
Description
What is the issue with the File System Standard?
https://fs.spec.whatwg.org/#write-a-chunk throws when getting a non-FileSystemWriteChunkType:
Let input be the result of converting chunk to a FileSystemWriteChunkType. If this throws an exception, then return a promise rejected with that exception.
But the spec does not say whether this exception should release the lock. In fact, the release only happens within:
- closeAlgorithm (step 4.2.2.4.1 in https://fs.spec.whatwg.org/#create-a-new-filesystemwritablefilestream)
- abortAlgorithm (step 5.1.1 in https://fs.spec.whatwg.org/#create-a-new-filesystemwritablefilestream)
- close() method (https://fs.spec.whatwg.org/#dom-filesystemsyncaccesshandle-close)
Errors from writeAlgorithm does not release the lock at all per the spec, as returning a rejected promise is not enough, which leads to a permanent lock as there's no GC-triggered lock release either.
The FS spec probably can get some algorithm to return a promise that waits for the lock release and use it for each exception, but that's sad as the implementations should do extra care for every implementation-specific error conditions. Could be nice if the Streams spec had some async hook to handle the error.