Fix Jinja2 template errors from invalid parameter/block names with special characters (SKY-7356) (#4644)

skyvern/utils/strings.py

@@ -1,5 +1,6 @@
 import os
 import random
+import re
 import string
 import uuid
 
@@ -18,3 +19,30 @@ def is_uuid(string: str) -> bool:
         return True
     except ValueError:
         return False
+
+
+def sanitize_identifier(value: str, default: str = "identifier") -> str:
+    """Sanitizes a string to be a valid Python/Jinja2 identifier.
+
+    Replaces non-alphanumeric characters (except underscores) with underscores,
+    collapses consecutive underscores, strips leading/trailing underscores,
+    and prepends an underscore if the result starts with a digit.
+
+    Args:
+        value: The raw value to sanitize.
+        default: Fallback value if everything is stripped.
+
+    Returns:
+        A sanitized string that is a valid Python identifier.
+    """
+    sanitized = re.sub(r"[^a-zA-Z0-9_]", "_", value)
+    sanitized = re.sub(r"_+", "_", sanitized)
+    sanitized = sanitized.strip("_")
+
+    if sanitized and sanitized[0].isdigit():
+        sanitized = "_" + sanitized
+
+    if not sanitized:
+        sanitized = default
+
+    return sanitized