Autocomplete incorrectly suggests transitive files from monorepo package

🔎 Search Terms

"autocomplete transitive", "autocomplete export null", "auto-import workspace package", "monorepo auto-import"

🕗 Version & Regression Information

This is the behavior in every version I tried, and I reviewed the FAQ for entries about "Auto-import Heuristics and Preferences". Notably, I think this line from the FAQ is appropriate:

It operates under a few key assumptions:
...
2. It's a bad idea to import things that won't work

⏯ Playground Link

This involves several files, so I've included a fourslash test below.

💻 Code

Below is a failing fourslash test that I put at tests/cases/fourslash/server/autoImportProviderTransitiveLeak.ts:

/// <reference path="../fourslash.ts" />

// @Filename: /home/src/workspaces/project/tsconfig.base.json
//// {
////   "compilerOptions": {
////     "module": "nodenext",
////     "composite": true,
////     "outDir": "${configDir}/dist"
////   }
//// }

// packages/foo

// @Filename: /home/src/workspaces/project/packages/foo/package.json
//// { "name": "@packages/foo", "type": "module", "version": "1.0.0", "exports": { ".": { "types": "./src/index.ts", "default": "./dist/index.js" }, "./internal/*": null } }

// @Filename: /home/src/workspaces/project/packages/foo/tsconfig.json
//// { "extends": "../../tsconfig.base.json" }

// @Filename: /home/src/workspaces/project/packages/foo/src/internal/index.ts
//// export function fooInternal() { console.log("foo"); }

// @Filename: /home/src/workspaces/project/packages/foo/src/index.ts
//// import { fooInternal } from "./internal/index.js"
////
//// export function foo() { fooInternal(); }

// packages/bar

// @Filename: /home/src/workspaces/project/packages/bar/package.json
//// { "name": "@packages/bar", "type": "module", "version": "1.0.0", "exports": { ".": { "types": "./src/index.ts", "default": "./dist/index.js" }, "./internal/*": null }, "dependencies": { "@packages/foo": "*" } }

// @Filename: /home/src/workspaces/project/packages/bar/tsconfig.json
//// { "extends": "../../tsconfig.base.json" }

// @Filename: /home/src/workspaces/project/packages/bar/src/index.ts
//// fo/**/

// npm workspaces

// @Filename: /home/src/workspaces/project/package.json
//// { "workspaces": ["packages/*"], "type": "module" }

// @link: /home/src/workspaces/project/packages/foo -> /home/src/workspaces/project/node_modules/@packages/foo
// @link: /home/src/workspaces/project/packages/bar -> /home/src/workspaces/project/node_modules/@packages/bar

goTo.marker("");

verify.completions({
  marker: "",
  includes: [
    {
      name: "foo",
      source: "@packages/foo",
      sourceDisplay: "@packages/foo",
      hasAction: true,
      sortText: completion.SortText.AutoImportSuggestions,
    },
  ],
  excludes: ["fooInternal"],
  preferences: {
    includeCompletionsForModuleExports: true,
    allowIncompleteCompletions: true,
  },
});

🙁 Actual behavior

When replicating this in a repository, autocomplete suggests fooInternal via a relative path import. Accepting this import results in the following code that has a red squiggly on the import line and fails to compile:

import { fooInternal } from "../../foo/src/internal/index.js";

fooInternal

The error is:

File '<elided>/packages/foo/src/internal/index.ts' is not under 'rootDir' '<elided>/packages/bar/src'. 'rootDir' is expected to contain all source files.

🙂 Expected behavior

I believe that fooInternal should not be suggested because it's "a bad idea to import things that won't work" per the FAQ. This import won't work for two reasons:

1. It is not in the current Typescript project, nor is it referenced.
2. Even if it suggested the package path and not a relative path, it is blocked by the NodeJS exports.

Additional information about the issue

After doing some initial investigation with Claude to identify the source of the bug, I noticed that getNodeModulesPackageNameFromFileName might have theoretically worked here, but it does not because these are symlinks due to being workspace packages, which are resolved to a non-node_modules directory. I tried the test with "preserveSymlinks": true, however, and the bug still occurred. This appears to be because AutoImportProviderProject unconditionally resolves the symlink, which may or may not be appropriate, I'm not sure.

I'm happy to provide more context about why we want fooInternal to not be suggested, but I hope it's clear from the reproduction case.

tests/cases/fourslash/server/autoImportProviderTransitiveLeak.ts から始め、失敗している fourslash テストを実行します。workspace のシンボリックリンクと package exports がどのように扱われるかを調査しながら、getNodeModulesPackageNameFromFileName と AutoImportProviderProject を追跡します。foo が引き続き @packages/foo から候補として提示され、fooInternal が除外されれば完了です。