Duplicate import path completions when multiple root directories are present

[PhoebeSzmucer]

🔎 Search Terms

autocomplete, duplicate suggestions, duplicate imports, root dirs

🕗 Version & Regression Information

• This is the behavior in every version I tried, but was made worse after Fix an off-by-one error in getBaseDirectoriesFromRootDirs #55233 (v5.3-beta and later)

💻 Code

When rootDirs are src/ and build/dts, and the directory structure is following:

app/
  src/
    index.ts
    dir/
      a.module.scss
  build/
    dts/
      index.d.ts
      dir/
        a.module.scss.d.ts

🙁 Actual behavior

Import completions when invoked from index.ts (using import {} from "./) have a duplicate entry for dir

🙂 Expected behavior

Only a single entry for dir is present.

Additional information about the issue

The bug occurs because when we're combining completions from the point of view of each root dir, we're not deduplicating the entries.

This issue has existed for a long time, but it was made more obvious after #55233 fixed a related bug.