Cherry-pick PR #39924 into release-4.0

Component commits:
45d9eb5 place first import after header

d35d719 don't insert before non-header

Author: jessetrinity

src/services/textChanges.ts

@@ -384,8 +384,8 @@ namespace ts.textChanges {
             }
         }
 
-        public insertNodeBefore(sourceFile: SourceFile, before: Node, newNode: Node, blankLineBetween = false): void {
-            this.insertNodeAt(sourceFile, getAdjustedStartPosition(sourceFile, before, {}), newNode, this.getOptionsForInsertNodeBefore(before, newNode, blankLineBetween));
+        public insertNodeBefore(sourceFile: SourceFile, before: Node, newNode: Node, blankLineBetween = false, options: ConfigurableStartEnd = {}): void {
+            this.insertNodeAt(sourceFile, getAdjustedStartPosition(sourceFile, before, options), newNode, this.getOptionsForInsertNodeBefore(before, newNode, blankLineBetween));
         }
 
         public insertModifierBefore(sourceFile: SourceFile, modifier: SyntaxKind, before: Node): void {

src/services/utilities.ts

@@ -1913,7 +1913,10 @@ namespace ts {
             for (const newImport of sortedNewImports) {
                 const insertionIndex = OrganizeImports.getImportDeclarationInsertionIndex(existingImportStatements, newImport);
                 if (insertionIndex === 0) {
-                    changes.insertNodeBefore(sourceFile, existingImportStatements[0], newImport, /*blankLineBetween*/ false);
+                    // If the first import is top-of-file, insert after the leading comment which is likely the header.
+                    const options = existingImportStatements[0] === sourceFile.statements[0] ?
+                    { leadingTriviaOption: textChanges.LeadingTriviaOption.Exclude } : {};
+                    changes.insertNodeBefore(sourceFile, existingImportStatements[0], newImport, /*blankLineBetween*/ false, options);
                 }
                 else {
                     const prevImport = existingImportStatements[insertionIndex - 1];

tests/cases/fourslash/importNameCodeFix_HeaderComment1.ts

@@ -0,0 +1,26 @@
+/// <reference path="fourslash.ts" />
+
+// @Filename: /a.ts
+////export const foo = 0;
+
+// @Filename: /b.ts
+////export const bar = 0;
+
+// @Filename: /c.ts
+/////*--------------------
+//// *  Copyright Header
+//// *--------------------*/
+////
+////import { bar } from "./b";
+////foo;
+
+goTo.file("/c.ts");
+verify.importFixAtPosition([
+`/*--------------------
+ *  Copyright Header
+ *--------------------*/
+
+import { foo } from "./a";
+import { bar } from "./b";
+foo;`,
+]);

tests/cases/fourslash/importNameCodeFix_HeaderComment2.ts

@@ -0,0 +1,32 @@
+/// <reference path="fourslash.ts" />
+
+// @Filename: /a.ts
+////export const foo = 0;
+
+// @Filename: /b.ts
+////export const bar = 0;
+
+// @Filename: /c.ts
+/////*--------------------
+//// *  Copyright Header
+//// *--------------------*/
+////
+////const afterHeader = 1;
+////
+////// non-header comment
+////import { bar } from "./b";
+////foo;
+
+goTo.file("/c.ts");
+verify.importFixAtPosition([
+`/*--------------------
+ *  Copyright Header
+ *--------------------*/
+
+const afterHeader = 1;
+
+import { foo } from "./a";
+// non-header comment
+import { bar } from "./b";
+foo;`,
+]);