fixing the global flags issue in joomla_template_scan and drupal_theme_scan (#1091)

* fixing the global flags issue in joomla template and drupal theme scans, and adding a regex validation testcase

* ruff fixes

nettacker/modules/scan/drupal_theme.yaml

@@ -37,5 +37,5 @@ payloads:
           condition_type: or
           conditions:
             content:
-              regex: \/(?i)\bthemes\b\/(.+?)\/
+              regex: (?i)\/\bthemes\b\/(.+?)\/
               reverse: false

nettacker/modules/scan/joomla_template.yaml

@@ -40,5 +40,5 @@ payloads:
           condition_type: or
           conditions:
             content:
-              regex: \/(?i)\badministrator\/templates\b\/(.+?)\/|\/(?i)templates\/(.+?)\/
+              regex: (?i)\/\badministrator\/templates\b\/(.+?)\/|\/templates\/(.+?)\/
               reverse: false

tests/test_yaml_regexes.py

@@ -0,0 +1,87 @@
+import os
+import re
+
+import pytest
+import yaml
+
+BASE_DIRS = ["nettacker/modules/vuln", "nettacker/modules/scan"]
+DUMMY_TEST_STRING = (
+    "This is a random string for testing regex 220-You are user number HTTP/1.1 200 OK"
+)
+
+
+def get_yaml_files():
+    for base in BASE_DIRS:
+        for file in os.listdir(base):
+            if file.endswith(".yaml"):
+                yield os.path.join(base, file)
+
+
+def load_yaml(file_path):
+    with open(file_path, "r") as f:
+        return yaml.safe_load(f)
+
+
+def extract_http_regexes(payloads):
+    regexes = []
+    for payload in payloads:
+        if payload.get("library") != "http":
+            continue
+        for step in payload.get("steps", []):
+            conditions = step.get("response", {}).get("conditions", {})
+            if "content" in conditions and "regex" in conditions["content"]:
+                regexes.append(conditions["content"]["regex"])
+    return regexes
+
+
+def extract_socket_regexes(file_name, payloads):
+    regexes = []
+
+    for payload in payloads:
+        if payload.get("library") != "socket":
+            continue
+        for step in payload.get("steps", []):
+            conditions = step.get("response", {}).get("conditions", {})
+
+            if "service" in conditions:  # for port.yaml
+                services = conditions["service"]
+                for service_block in services.values():
+                    if isinstance(service_block, dict) and "regex" in service_block:
+                        regexes.append(service_block["regex"])
+
+            elif "time_response" in conditions:  # for icmp.yaml
+                tr = conditions["time_response"]
+                if isinstance(tr, dict) and "regex" in tr:
+                    regexes.append(tr["regex"])
+
+    return regexes
+
+
+def is_valid_regex(regex: str) -> bool:
+    try:
+        pattern = re.compile(regex)
+        re.findall(pattern, DUMMY_TEST_STRING)
+        return True
+    except Exception:
+        return False
+
+
+@pytest.mark.parametrize("yaml_file", list(get_yaml_files()))
+def test_yaml_regexes_valid(yaml_file):
+    data = load_yaml(yaml_file)
+    payloads = data.get("payloads", [])
+
+    if not payloads:
+        pytest.skip(f"No payloads found in {yaml_file}")
+
+    if payloads[0].get("library") == "http":
+        regexes = extract_http_regexes(payloads)
+    elif payloads[0].get("library") == "socket":
+        file_name = os.path.basename(yaml_file)
+        regexes = extract_socket_regexes(file_name, payloads)
+    else:
+        pytest.skip(f"Unknown library type in {yaml_file}")
+        return
+
+    for regex in regexes:
+        assert is_valid_regex(regex), f"Invalid regex in {yaml_file}: `{regex}`"