Auto-import does not suggest updates from symlinked monorepo package sources

[ericnorris]

Extension Version

0.20260124.1

VS Code Version

1.108.2

Operating system Version

macOS 15.7

Steps to reproduce

I've written a failing fourslash test to demonstrate the issue:

package fourslash_test

import (
	"testing"

	"github.com/microsoft/typescript-go/internal/fourslash"
	. "github.com/microsoft/typescript-go/internal/fourslash/tests/util"
	"github.com/microsoft/typescript-go/internal/ls"
	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
	"github.com/microsoft/typescript-go/internal/testutil"
)

const TestAutoImportSymlinkedMonorepoSourceUpdateScenario = `
// @Filename: /home/src/workspaces/project/tsconfig.base.json
{
  "compilerOptions": {
    "module": "nodenext",
    "moduleResolution": "nodenext",
	"composite": true
  }
}

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

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

// @Filename: /home/src/workspaces/project/packages/foo/src/index.ts
/*fooEdit*/

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

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

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

func TestAutoImportSymlinkedMonorepoSourceUpdate(t *testing.T) {
	t.Parallel()

	defer testutil.RecoverAndFail(t, "Panic on fourslash test")

	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, TestAutoImportSymlinkedMonorepoSourceUpdateScenario)

	defer done()

	// force auto import to build the cache
	f.BaselineAutoImportsCompletions(t, []string{"fooCompletion"})

	// add the new function
	f.GoToMarker(t, "fooEdit")
	f.Insert(t, "\nexport function foo() {}")

	// function should show up
	f.VerifyCompletions(t, "fooCompletion", &fourslash.CompletionsExpectedList{
		IsIncomplete: false,
		ItemDefaults: &fourslash.CompletionsExpectedItemDefaults{
			CommitCharacters: &DefaultCommitCharacters,
			EditRange:        Ignored,
		},
		Items: &fourslash.CompletionsExpectedItems{
			Includes: []fourslash.CompletionsExpectedItem{
				&lsproto.CompletionItem{
					Label:               "foo",
					AdditionalTextEdits: fourslash.AnyTextEdits,
					SortText:            PtrTo(string(ls.SortTextLocationPriority)),
				},
			},
		},
	})
}

I placed it at internal/fourslash/tests/autoImportSymlinkedMonorepoSourceUpdate_test.go.

Issue

It seems that the auto-import cache doesn't update for edits to symlinked workspace packages in a monorepo when types in a package.json points to the source Typescript. I would expect that it would, as this would make working in a monorepo pretty seamless for developers.

I'm happy to give more context about the related issues I've filed (#2581, and one in the Typescript repository) if that helps!