moveToNewFile: Fix bug for VariableDeclaration missing initializer (#24214)

Author: Andy

src/services/refactors/moveToNewFile.ts

@@ -433,7 +433,7 @@ namespace ts.refactor {
     }
     function isVariableDeclarationInImport(decl: VariableDeclaration) {
         return isSourceFile(decl.parent.parent.parent) &&
-            isRequireCall(decl.initializer, /*checkArgumentIsStringLiteralLike*/ true);
+            decl.initializer && isRequireCall(decl.initializer, /*checkArgumentIsStringLiteralLike*/ true);
     }
 
     function filterImport(i: SupportedImport, moduleSpecifier: StringLiteralLike, keep: (name: Identifier) => boolean): SupportedImportStatement | undefined {

tests/cases/fourslash/moveToNewFile_variableDeclarationWithNoInitializer.ts

@@ -0,0 +1,19 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: /a.ts
+////export {};
+////let x;
+////[|const y = x;|]
+
+verify.moveToNewFile({
+    newFileContents: {
+        "/a.ts":
+`export {};
+export let x;
+`,
+
+        "/y.ts":
+`import { x } from "./a";
+const y = x;`,
+    },
+});