Potential fix for code scanning alert no. 19: Incomplete string escaping or encoding

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: involvex

src/tests/mocks/edge-case-generators.ts

@@ -65,12 +65,14 @@ export function generateWhitespaceVariations(base: string): string[] {
 }
 
 export function generateNewlineVariations(content: string): string[] {
+  const escapeForDoubleQuoted = (s: string): string =>
+    s.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
   return [
-    content.replace(/"/g, '\\"'),
-    content.replace(/"/g, '\\"').replace(/\n/g, "\r\n"),
-    content.replace(/"/g, '\\"').replace(/\n/g, "\r"),
-    content.replace(/"/g, '\\"').replace(/\n/g, "\n\n"),
-    content.replace(/"/g, '\\"').replace(/\n/g, "\r\n\r\n"),
+    escapeForDoubleQuoted(content),
+    escapeForDoubleQuoted(content).replace(/\n/g, "\r\n"),
+    escapeForDoubleQuoted(content).replace(/\n/g, "\r"),
+    escapeForDoubleQuoted(content).replace(/\n/g, "\n\n"),
+    escapeForDoubleQuoted(content).replace(/\n/g, "\r\n\r\n"),
     `${content}\n`,
     `${content}\r\n`,
     `${content}\n\n`,