stat.isFIFO() is wrongly marked as always false on Windows, even when piping into a node process
Nobody has claimed this yet.
- Dominant language
- JavaScript
- Stars
- 122k
- Forks
- 37.3k
- Avg merge
- 4d 2h
- Merged PRs (30d)
- 283
Description
Version
v22.14.0
Platform
Microsoft Windows NT 10.0.26120.0 x64 [although this is on ARM64]
Subsystem
No response
What steps will reproduce the bug?
Running echo '{}' | node -e 'console.log(require("fs").fstatSync(0).mode)' in PowerShell (as cmd doesn't seem to support pipes via the usual syntax) returns 4096, and checking fs.constants, S_IFIFO is set to 4096.
How often does it reproduce? Is there a required condition?
Seems to be all the time on Windows when you try to pipe something in, which is due to a (I assume legacy?) check here: https://github.com/nodejs/node/blob/c3b6f949748b49ef25b0239bd4582d29976fdbad/lib/internal/fs/utils.js#L538-L541
What is the expected behavior? Why is that the expected behavior?
On Windows, stat.isFIFO() should correctly handle pipes and stat.isFIFO() should correctly return true when piped in
What do you see instead?
stat.isFIFO() always returns false on Windows, even if the mode has the flag set
Additional information
I would love to submit a PR to fix this, but I am not sure if those checks are there for a reason or for legacy purposes (it seems that at least the S_ISFIFO is now exposed but it wasn't before [?]), and if it can be edited safely.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Run the reported PowerShell pipeline on Windows, then inspect the platform-specific checks in lib/internal/fs/utils.js around lines 538-541. Determine why FIFO detection excludes Windows pipes and verify that stat.isFIFO() returns true for the piped stdin case without changing other file-type checks.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript, node.js
- Domain
- operating-systems
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 55/100