Fix an off-by-one error in getBaseDirectoriesFromRootDirs

[PhoebeSzmucer]

Fixes #55232

I couldn't find where this is tested (if it even is). If someone can help me out with that I can write a test.

[sheetalkamat]

You would need to add test in src/testRunner/unittests/tsserver/autoImportProvider.ts following example of one of the test case there.

[PhoebeSzmucer]

You would need to add test in src/testRunner/unittests/tsserver/autoImportProvider.ts following example of one of the test case there.

Isn't that for auto-import and not path completion? Or do these go through the same code path?

[PhoebeSzmucer]

I added a throw statement to getBaseDirectoriesFromRootDirs and the only test that failed was tests/cases/fourslash/completionForStringLiteralRelativeImport4.ts

[PhoebeSzmucer]

@microsoft-github-policy-service agree company="Palantir"

[PhoebeSzmucer]

@sheetalkamat I added a fourslash test that failed before and succeeds now

[PhoebeSzmucer]

@sheetalkamat any chance this can make it to the 5.2 release?

[jakebailey]

5.2 was branched off a while ago and main is now targeting 5.3; see #54298. Given this bug isn't a regression from 5.1, I wouldn't expect to see it backported unless it's causing major ecosystem pain.

[PhoebeSzmucer]

I had to also add removeTrailingDirectorySeparator here because otherwise some tests got broken due to duplicated entries with mismatched trailing slashes. It's probably a good idea to return consistent results anyway.