fix(50888): Organize Imports may delete preceding comments when all members of all import statements are unused (#50983)

* fix(50888): preserve preceding comments of the deleted import

* update tests

Author: a-tarasyuk

src/services/organizeImports.ts

@@ -145,6 +145,7 @@ export function organizeImports(
             // Consider the first node to have trailingTrivia as we want to exclude the
             // "header" comment.
             changeTracker.deleteNodes(sourceFile, oldImportDecls, {
+                leadingTriviaOption: textChanges.LeadingTriviaOption.Exclude,
                 trailingTriviaOption: textChanges.TrailingTriviaOption.Include,
             }, /*hasTrailingComment*/ true);
         }

tests/cases/fourslash/organizeImports14.ts

@@ -0,0 +1,33 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: /a.ts
+////export const foo = 1;
+
+// @filename: /b.ts
+/////**
+//// * Module doc comment
+//// *
+//// * @module
+//// */
+////
+////// comment 1
+////
+////// comment 2
+////
+////import { foo } from "./a";
+////import { foo } from "./a";
+////import { foo } from "./a";
+
+goTo.file("/b.ts");
+verify.organizeImports(
+`/**
+ * Module doc comment
+ *
+ * @module
+ */
+
+// comment 1
+
+// comment 2
+
+`);

tests/cases/fourslash/organizeImports15.ts

@@ -0,0 +1,31 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: /a.ts
+////export const foo = 1;
+
+// @filename: /b.ts
+/////**
+//// * Module doc comment
+//// *
+//// * @module
+//// */
+////
+////// comment 1
+////
+////// comment 2
+////
+////import { foo } from "./a";
+
+goTo.file("/b.ts");
+verify.organizeImports(
+`/**
+ * Module doc comment
+ *
+ * @module
+ */
+
+// comment 1
+
+// comment 2
+
+`);