Fix ErrNeedsAutoImports panic when autoImportFileExcludePatterns changes (#2812)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: andrewbranch <3277153+andrewbranch@users.noreply.github.com>

Author: Copilot

internal/ls/autoimport/registry.go

@@ -673,7 +673,9 @@ func (b *registryBuilder) updateIndexes(ctx context.Context, change RegistryChan
 			dependencies := b.computeDependenciesForNodeModulesDirectory(change, allResolvedPackageNames, dirName, dirPath)
 			bucketState := nodeModulesBucket.Value().state
 			// !!! Optimization: handle different dependency set via granular updates
-			needsFullRebuild := bucketState.multipleFilesDirty || !nodeModulesBucket.Value().DependencyNames.Equals(dependencies)
+			needsFullRebuild := bucketState.multipleFilesDirty ||
+				!nodeModulesBucket.Value().DependencyNames.Equals(dependencies) ||
+				!core.UnorderedEqual(bucketState.fileExcludePatterns, b.userPreferences.AutoImportFileExcludePatterns)
 			dirtyPackages := bucketState.DirtyPackages()
 			canDoGranularUpdate := !needsFullRebuild && dirtyPackages.Len() > 0
 
@@ -701,7 +703,8 @@ func (b *registryBuilder) updateIndexes(ctx context.Context, change RegistryChan
 	if project, hasProject := b.projects.Get(projectPath); hasProject {
 		program := b.host.GetProgramForProject(projectPath)
 		resolvedPackageNames := allResolvedPackageNames[projectPath]
-		shouldRebuild := project.Value().state.hasDirtyFileBesides(change.RequestedFile)
+		shouldRebuild := project.Value().state.hasDirtyFileBesides(change.RequestedFile) ||
+			!core.UnorderedEqual(project.Value().state.fileExcludePatterns, b.userPreferences.AutoImportFileExcludePatterns)
 		if !shouldRebuild && project.Value().state.newProgramStructure > 0 {
 			// Check if resolved package names changed, or if there are new non-node_modules files.
 			// If so, we need to rebuild both the project bucket and potentially node_modules buckets.

internal/ls/autoimport/registry_test.go

@@ -6,8 +6,10 @@ import (
 	"testing"
 
 	"github.com/microsoft/typescript-go/internal/collections"
+	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/ls/autoimport"
 	"github.com/microsoft/typescript-go/internal/ls/lsconv"
+	"github.com/microsoft/typescript-go/internal/ls/lsutil"
 	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
 	"github.com/microsoft/typescript-go/internal/project"
 	"github.com/microsoft/typescript-go/internal/testutil/autoimporttestutil"
@@ -497,6 +499,63 @@ export declare const otherValue: string;`,
 		nodeModulesBucket = singleBucket(t, stats.NodeModulesBuckets)
 		assert.Equal(t, nodeModulesBucket.State.Dirty(), false, "bucket should be clean after rebuild")
 	})
+
+	t.Run("changed fileExcludePatterns triggers bucket rebuild", func(t *testing.T) {
+		t.Parallel()
+		fixture := autoimporttestutil.SetupLifecycleSession(t, lifecycleProjectRoot, 1)
+		session := fixture.Session()
+		project := fixture.SingleProject()
+		mainFile := project.File(0)
+
+		ctx := context.Background()
+
+		// Open file and build auto-imports initially
+		session.DidOpenFile(ctx, mainFile.URI(), 1, mainFile.Content(), lsproto.LanguageKindTypeScript)
+		_, err := session.GetLanguageServiceWithAutoImports(ctx, mainFile.URI())
+		assert.NilError(t, err)
+
+		// Verify buckets are clean after initial build
+		stats := autoImportStats(t, session)
+		projectBucket := singleBucket(t, stats.ProjectBuckets)
+		nodeModulesBucket := singleBucket(t, stats.NodeModulesBuckets)
+		assert.Equal(t, false, projectBucket.State.Dirty())
+		assert.Equal(t, false, nodeModulesBucket.State.Dirty())
+
+		// IsPreparedForImportingFile should return true with no exclude patterns
+		snapshot, release := session.Snapshot()
+		defaultProject := snapshot.GetDefaultProject(mainFile.URI())
+		assert.Assert(t, defaultProject != nil)
+		projectPath := defaultProject.ConfigFilePath()
+		preferences := lsutil.NewDefaultUserPreferences()
+		preferences.IncludeCompletionsForModuleExports = core.TSTrue
+		preferences.IncludeCompletionsForImportStatements = core.TSTrue
+		isPrepared := snapshot.AutoImportRegistry().IsPreparedForImportingFile(mainFile.FileName(), projectPath, preferences)
+		release()
+		assert.Assert(t, isPrepared)
+
+		// Change the file exclude patterns preference
+		newPreferences := lsutil.NewDefaultUserPreferences()
+		newPreferences.IncludeCompletionsForModuleExports = core.TSTrue
+		newPreferences.IncludeCompletionsForImportStatements = core.TSTrue
+		newPreferences.AutoImportFileExcludePatterns = []string{"**/node_modules/**/*.d.ts"}
+		session.Configure(lsutil.NewUserConfig(newPreferences))
+
+		// IsPreparedForImportingFile should return false since exclude patterns changed
+		snapshot2, release2 := session.Snapshot()
+		isPrepared2 := snapshot2.AutoImportRegistry().IsPreparedForImportingFile(mainFile.FileName(), projectPath, newPreferences)
+		release2()
+		assert.Assert(t, !isPrepared2)
+
+		// After GetLanguageServiceWithAutoImports, buckets should be rebuilt
+		_, err = session.GetLanguageServiceWithAutoImports(ctx, mainFile.URI())
+		assert.NilError(t, err)
+
+		// IsPreparedForImportingFile should return true now that buckets are rebuilt
+		snapshot3, release3 := session.Snapshot()
+		isPrepared3 := snapshot3.AutoImportRegistry().IsPreparedForImportingFile(mainFile.FileName(), projectPath, newPreferences)
+		release3()
+		assert.Assert(t, isPrepared3, "IsPreparedForImportingFile should return true after bucket rebuild with new fileExcludePatterns")
+	})
 }
 
 const (