TypeError: fsevents.watch is not a function

[mutantcornholio]

Describe the bug

fsevents@~2.3.3 is an optional dependency for vite, and vite can run fine without it.
However, if some other package adds fsevents@1, vite breaks:

file:///Users/cornholio/dev/tmp/vite-bug/node_modules/vite/dist/node/chunks/dep-CB_7IfJ-.js:43399
  const stop = fsevents.watch(path, callback);
                        ^

TypeError: fsevents.watch is not a function
    at createFSEventsInstance (file:///Users/cornholio/dev/tmp/vite-bug/node_modules/vite/dist/node/chunks/dep-CB_7IfJ-.js:43399:25)
    at setFSEventsListener (file:///Users/cornholio/dev/tmp/vite-bug/node_modules/vite/dist/node/chunks/dep-CB_7IfJ-.js:43455:16)
    at FsEventsHandler._watchWithFsEvents (file:///Users/cornholio/dev/tmp/vite-bug/node_modules/vite/dist/node/chunks/dep-CB_7IfJ-.js:43659:18)
    at FsEventsHandler.initWatch (file:///Users/cornholio/dev/tmp/vite-bug/node_modules/vite/dist/node/chunks/dep-CB_7IfJ-.js:43735:23)
    at FsEventsHandler._addToFsEvents (file:///Users/cornholio/dev/tmp/vite-bug/node_modules/vite/dist/node/chunks/dep-CB_7IfJ-.js:43824:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

Node.js v22.6.0

Reproduction

probably not reproducible on linux, as fsevents is a mac package

Steps to reproduce

npm init
# remixd depends on chokidar@2.1.8, which depends on fsevents@^1.2.7
npm install --save vite @remix-project/remixd

System Info

node v22.6.0
npm 10.9.0
macOS 14.7.1

Used Package Manager

npm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[bluwy]

Isn't this more of a bug in the package manager where it's not installing or providing the correct version of fsevents for Vite?

[mutantcornholio]

Ideally, yes.
It can be solved on package manager level, and I think yarn's PnP shouldn't be susceptible, for example.
I wouldn't get my hopes up about npm fixing it though anytime soon. It's just the way node_modules work, and I think a lot of code in the industry actually expects it to work like that.

UPD: wait a second... I was under impression that vite's using fsevents directly (as it lists fsevents in its optionalDependencies), but it looks like it uses fsevents via chokidar instead? Probably should be directed to chokidar then..
I even found an (unfortunately closed) issue there paulmillr/chokidar#1180

[bluwy]

I wouldn't get my hopes up about npm fixing it though anytime soon. It's just the way node_modules work, and I think a lot of code in the industry actually expects it to work like that.

Why not? npm is not giving us the right version based on the semver range we've specified and this looks like a legitimate bug. Is this already reported on npm or other package managers?

About chokidar, I doubt they'll make any fix soon as v4 already removed fsevents. We're still on v3 which uses it because there's regressions in v4 that were not ready yet.

I feel like it's better to place the effort into fixing the source of the issue than patching or adding workarounds.

[mutantcornholio]

After running the repro with --verbose, I see that it actually fails to compile fsevents@2.3.3:

npm info run fsevents@1.2.13 install node_modules/fsevents node install.js
npm info run fsevents@2.3.3 install node_modules/rollup/node_modules/fsevents node-gyp rebuild
npm info run fsevents@2.3.3 install node_modules/vite/node_modules/fsevents node-gyp rebuild
npm info run fsevents@2.3.3 install { code: 1, signal: null }
npm verbose reify failed optional dependency /Users/cornholio/dev/tmp/2/node_modules/rollup/node_modules/fsevents
npm info run fsevents@2.3.3 install { code: 1, signal: null }
npm verbose reify failed optional dependency /Users/cornholio/dev/tmp/2/node_modules/vite/node_modules/fsevents

I think it might be related to npm/cli#4859

[sapphi-red]

I also think that this should be fixed on the package manager side.
In addition, fsevents@2 was released 6 years ago so I assume there won't be many users encountering this.