microsoft · Noamaan Mulla (noamaanMulla-03) · Sep 15, 2026
diff --git a/tsc/internal/fourslash/tests/codeFixConvertToTypeOnlyImportComments_test.go b/tsc/internal/fourslash/tests/codeFixConvertToTypeOnlyImportComments_test.go
@@ -0,0 +1,31 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/TypeScript/tsc/internal/fourslash"
+	"github.com/microsoft/TypeScript/tsc/internal/testutil"
+)
+
+func TestCodeFixConvertToTypeOnlyImportPreservesComments(t *testing.T) {
+	t.Parallel()
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+	const content = `// @module: esnext
+// @verbatimModuleSyntax: true
+// @Filename: /foo.ts
+export type foo = "foo";
+// @Filename: /index.ts
+// upper comment
+/*left comment*/ import { fo/**/o } from "./foo"; // right comment
+// lower comment`
+	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	defer done()
+	f.GoToMarker(t, "")
+	f.VerifyCodeFix(t, fourslash.VerifyCodeFixOptions{
+		Description: "Use 'import type'",
+		NewFileContent: `// upper comment
+/*left comment*/ import type { foo } from "./foo"; // right comment
+// lower comment`,
+		Index: 0,
+	})
+}
diff --git a/tsc/internal/ls/codeactions.go b/tsc/internal/ls/codeactions.go
@@ -70,6 +70,7 @@ type CombinedCodeActions struct {
 // codeFixProviders is the list of all registered code fix providers
 var codeFixProviders = []*CodeFixProvider{
 	ImportFixProvider,
+	ConvertToTypeOnlyImportProvider,
 	IsolatedDeclarationsFixProvider,
 	FixClassIncorrectlyImplementsInterfaceProvider,
 	// Add more code fix providers here as they are implemented

diff --git a/tsc/internal/ls/codeactions_converttotypeonlyimport.go b/tsc/internal/ls/codeactions_converttotypeonlyimport.go
@@ -0,0 +1,76 @@
+package ls
+
+import (
+	"context"
+
+	"github.com/microsoft/TypeScript/tsc/internal/ast"
+	"github.com/microsoft/TypeScript/tsc/internal/astnav"
+	"github.com/microsoft/TypeScript/tsc/internal/core"
+	"github.com/microsoft/TypeScript/tsc/internal/diagnostics"
+	"github.com/microsoft/TypeScript/tsc/internal/locale"
+	"github.com/microsoft/TypeScript/tsc/internal/ls/change"
+	"github.com/microsoft/TypeScript/tsc/internal/scanner"
+)
+
+const convertToTypeOnlyImportFixID = "convertToTypeOnlyImport"
+
+var convertToTypeOnlyImportErrorCodes = []int32{
+	diagnostics.X_0_is_a_type_and_must_be_imported_using_a_type_only_import_when_verbatimModuleSyntax_is_enabled.Code(),
+	diagnostics.X_0_resolves_to_a_type_only_declaration_and_must_be_imported_using_a_type_only_import_when_verbatimModuleSyntax_is_enabled.Code(),
+}
+
+var ConvertToTypeOnlyImportProvider = &CodeFixProvider{
+	ErrorCodes:     convertToTypeOnlyImportErrorCodes,
+	GetCodeActions: getConvertToTypeOnlyImportCodeActions,
+	FixIds:         []string{convertToTypeOnlyImportFixID},
+}
+
+func getConvertToTypeOnlyImportCodeActions(ctx context.Context, fixContext *CodeFixContext) ([]*CodeAction, error) {
+	importDeclaration := getImportDeclarationForSoleSpecifier(fixContext.SourceFile, fixContext.Span.Pos())
+	if importDeclaration == nil {
+		return nil, nil
+	}
+
+	tracker := change.NewTracker(ctx, fixContext.Program.Options(), fixContext.LS.FormatOptions(), fixContext.LS.converters)
+	// Do not reprint the import declaration: its attached trivia would be emitted
+	// again while the original comments remain outside the replacement range.
+	scan := scanner.GetScannerForSourceFile(fixContext.SourceFile, importDeclaration.Pos())
+	if scan.Token() != ast.KindImportKeyword {
+		return nil, nil
+	}
+	position := scan.TokenEnd()
+	tracker.ReplaceTextRangeWithText(fixContext.SourceFile, core.NewTextRange(position, position), " type")
+
+	changes, unmappable := tracker.GetChanges()
+	if len(unmappable) != 0 {
+		return nil, nil
+	}
+	return []*CodeAction{{
+		Description: diagnostics.Use_import_type.Localize(locale.FromContext(ctx)),
+		Changes:     changes[fixContext.SourceFile.OriginalFileName()],
+		FixID:       convertToTypeOnlyImportFixID,
+	}}, nil
+}
+
+// getImportDeclarationForSoleSpecifier limits this text-only edit to the
+// `import { Foo } from "..."` shape, where adding `type` changes no other import.
+func getImportDeclarationForSoleSpecifier(sourceFile *ast.SourceFile, pos int) *ast.Node {
+	token := astnav.GetTokenAtPosition(sourceFile, pos)
+	if token == nil || token.Parent == nil || token.Parent.Kind != ast.KindImportSpecifier {
+		return nil
+	}
+	specifier := token.Parent
+	if specifier.Parent == nil || specifier.Parent.Kind != ast.KindNamedImports || specifier.Parent.Parent == nil || specifier.Parent.Parent.Kind != ast.KindImportClause || specifier.Parent.Parent.Parent == nil || specifier.Parent.Parent.Parent.Kind != ast.KindImportDeclaration {
+		return nil
+	}
+
+	namedImports := specifier.Parent.AsNamedImports()
+	if len(namedImports.Elements.Nodes) != 1 || namedImports.Elements.Nodes[0] != specifier {
+		return nil
+	}
+	importClause := specifier.Parent.Parent.AsImportClause()
+	if importClause.IsTypeOnly() || importClause.Name() != nil {
+		return nil
+	}
+	return specifier.Parent.Parent.Parent
+}