feat(escape ansi): escape ansi ctrl codes from model output before displaying to user (#8636)

packages/cli/src/ui/utils/textUtils.ts

@@ -5,6 +5,7 @@
  */
 
 import stripAnsi from 'strip-ansi';
+import ansiRegex from 'ansi-regex';
 import { stripVTControlCharacters } from 'node:util';
 import stringWidth from 'string-width';
 
@@ -146,3 +147,70 @@ export const getCachedStringWidth = (str: string): number => {
 export const clearStringWidthCache = (): void => {
   stringWidthCache.clear();
 };
+
+const regex = ansiRegex();
+
+/* Recursively traverses a JSON-like structure (objects, arrays, primitives)
+ * and escapes all ANSI control characters found in any string values.
+ *
+ * This function is designed to be robust, handling deeply nested objects and
+ * arrays. It applies a regex-based replacement to all string values to
+ * safely escape control characters.
+ *
+ * To optimize performance, this function uses a "copy-on-write" strategy.
+ * It avoids allocating new objects or arrays if no nested string values
+ * required escaping, returning the original object reference in such cases.
+ *
+ * @param obj The JSON-like value (object, array, string, etc.) to traverse.
+ * @returns A new value with all nested string fields escaped, or the
+ * original `obj` reference if no changes were necessary.
+ */
+export function escapeAnsiCtrlCodes<T>(obj: T): T {
+  if (typeof obj === 'string') {
+    if (obj.search(regex) === -1) {
+      return obj; // No changes return original string
+    }
+
+    regex.lastIndex = 0; // needed for global regex
+    return obj.replace(regex, (match) =>
+      JSON.stringify(match).slice(1, -1),
+    ) as T;
+  }
+
+  if (obj === null || typeof obj !== 'object') {
+    return obj;
+  }
+
+  if (Array.isArray(obj)) {
+    let newArr: unknown[] | null = null;
+
+    for (let i = 0; i < obj.length; i++) {
+      const value = obj[i];
+      const escapedValue = escapeAnsiCtrlCodes(value);
+      if (escapedValue !== value) {
+        if (newArr === null) {
+          newArr = [...obj];
+        }
+        newArr[i] = escapedValue;
+      }
+    }
+    return (newArr !== null ? newArr : obj) as T;
+  }
+
+  let newObj: T | null = null;
+  const keys = Object.keys(obj);
+
+  for (const key of keys) {
+    const value = (obj as Record<string, unknown>)[key];
+    const escapedValue = escapeAnsiCtrlCodes(value);
+
+    if (escapedValue !== value) {
+      if (newObj === null) {
+        newObj = { ...obj };
+      }
+      (newObj as Record<string, unknown>)[key] = escapedValue;
+    }
+  }
+
+  return newObj !== null ? newObj : obj;
+}