address review: escape newline/carriage return, add unit tests

Also escape \n and \r in the module specifier, since an unescaped
newline would produce an unterminated string literal in the generated
file. Adds two test cases covering quote/backslash and newline/
carriage-return escaping in insertImport's output.

Author: herdiyana256

packages/schematics/angular/utility/ast-utils.ts

@@ -77,7 +77,11 @@ export function insertImport(
   // if there are no imports or 'use strict' statement, insert import at beginning of file
   const insertAtBeginning = allImports.length === 0 && useStrict.length === 0;
   const separator = insertAtBeginning ? '' : `;${eol}`;
-  const escapedFileName = fileName.replace(/\\/g, '\\\\').replace(/'/g, "\\'");
+  const escapedFileName = fileName
+    .replace(/\\/g, '\\\\')
+    .replace(/'/g, "\\'")
+    .replace(/\n/g, '\\n')
+    .replace(/\r/g, '\\r');
   const toInsert =
     `${separator}import ${open}${importExpression}${close}` +
     ` from '${escapedFileName}'${insertAtBeginning ? `;${eol}` : ''}`;

packages/schematics/angular/utility/ast-utils_spec.ts

@@ -768,6 +768,24 @@ describe('ast utils', () => {
 
       expect(result).toBe(fileContent);
     });
+
+    it('should escape single quotes and backslashes in the module specifier', () => {
+      const fileContent = '';
+      const source = getTsSource(filePath, fileContent);
+      const change = insertImport(source, filePath, 'Component', "foo'bar\\baz");
+      const result = applyChanges(filePath, fileContent, [change]).trim();
+
+      expect(result).toBe("import { Component } from 'foo\\'bar\\\\baz';");
+    });
+
+    it('should escape newlines and carriage returns in the module specifier', () => {
+      const fileContent = '';
+      const source = getTsSource(filePath, fileContent);
+      const change = insertImport(source, filePath, 'Component', 'foo\nbar\rbaz');
+      const result = applyChanges(filePath, fileContent, [change]).trim();
+
+      expect(result).toBe(`import { Component } from 'foo\\nbar\\rbaz';`);
+    });
   });
 
   describe('hasTopLevelIdentifier', () => {