Copying a Link from One File to Another Link to the Same File errors out in `isSrcSubdir`

[cowsandmilk]

• Operating System: MacOS, Linux
• Node.js version: 20.8.0, 18
• fs-extra version: 11.1.1

Set up

touch testFile
ln -s testFile testLink1
ln -s testFile testLink2

Then, in node:

fs.copy('testLink1', 'testLink2');
Uncaught Error: Cannot copy 'testFile' to a subdirectory of itself, 'testFile'.

There are no directories involved here. The call to copyLink would succeed perfectly fine and do the correct thing in this case.

[RyanZim]

Yeah, that's a bug. Out of curiosity, how does Node's experimental fs.cp behave here?

[cowsandmilk]

how does Node's experimental fs.cp behave here?

apparently a similar error as fs-extra

> fs.cpSync('testLink1', 'testLink2')
Uncaught:
SystemError [ERR_FS_CP_EINVAL]: Invalid src or dest: cp returned EINVAL (cannot copy /private/tmp/node_fs_test/testFile to a subdirectory of self /private/tmp/node_fs_test/testFile) testLink2
    at __node_internal_captureLargerStackTrace (node:internal/errors:497:5)
    at new SystemError (node:internal/errors:257:5)
    at new NodeError (node:internal/errors:368:7)
    at onLink (node:internal/fs/cp/cp-sync:315:11)
    at getStats (node:internal/fs/cp/cp-sync:181:12)
    at checkParentDir (node:internal/fs/cp/cp-sync:159:10)
    at cpSyncFn (node:internal/fs/cp/cp-sync:61:10)
    at Object.cpSync (node:fs:2987:3) {
  code: 'ERR_FS_CP_EINVAL',
  info: {
    message: 'cannot copy /private/tmp/node_fs_test/testFile to a subdirectory of self /private/tmp/node_fs_test/testFile',
    path: 'testLink2',
    syscall: 'cp',
    errno: 22,
    code: 'EINVAL'
  },
  errno: [Getter/Setter: 22],
  syscall: [Getter/Setter: 'cp'],
  path: [Getter/Setter: 'testLink2']
}

[RyanZim]

Yeah, fs.cp is based on fse.copy, so apparently this bug is both places. Should be raised as an issue on Node as well, so we can both fix it.

Just to make sure I understand this, in this particular case, performing a copy wouldn't actually change anything about the makeup of the filesystem, correct?

cc @manidlou

[cowsandmilk]

performing a copy wouldn't actually change anything about the makeup of the filesystem, correct?

that would be my expectation

[bstst]

it does indeed look like there's an issue here.

I have an electron app packaged with vite. the @electron-forge/vite-plugin does fs.copy on the files of packages in the package.json file. My project has a dependency on the @smile-cdr/fhirts package. I get this error ("src:" and "dst:" are my debug logs, just as the "catch me" tracer):

src: /Users/martin/Projects/CENSORED/node_modules/@istanbuljs/load-nyc-config/node_modules/js-yaml
dst: /var/folders/bm/ytnswbdd57b5dm28zg7x8ysc0000gn/T/electron-packager/tmp-8AxS5d/Electron.app/Contents/Resources/app/node_modules/@istanbuljs/load-nyc-config/node_modules/js-yaml

Trace: catch me
    at /Users/martin/Projects/CENSORED/node_modules/fs-extra/lib/copy/copy.js:213:19
    at FSReqCallback.oncomplete (node:fs:200:23)

An unhandled rejection has occurred inside Forge:
Error: Cannot copy '../../../../../../esprima/bin/esvalidate.js' to a subdirectory of itself, '../../../../../../esprima/bin/esvalidate.js'.
at /Users/martin/Projects/CENSORED/node_modules/fs-extra/lib/copy/copy.js:214:21
    at FSReqCallback.oncomplete (node:fs:200:23)