community: Add ZenGuard tool (#22959)

** Description**
This is the community integration of ZenGuard AI - the fastest
guardrails for GenAI applications. ZenGuard AI protects against:

- Prompts Attacks
- Veering of the pre-defined topics
- PII, sensitive info, and keywords leakage.
- Toxicity
- Etc.

**Twitter Handle** : @zenguardai

- [x] **Add tests and docs**: If you're adding a new integration, please
include
  1. Added an integration test
  2. Added colab


- [x] **Lint and test**: Run `make format`, `make lint` and `make test`
from the root of the package(s) you've modified.

---------

Co-authored-by: Nuradil <nuradil.maksut@icloud.com>
Co-authored-by: Nuradil <133880216+yaksh0nti@users.noreply.github.com>

libs/community/tests/integration_tests/tools/zenguard/test_zenguard.py

@@ -0,0 +1,104 @@
+import os
+from typing import Any, Dict, List
+
+import pytest
+
+from langchain_community.tools.zenguard.tools import Detector, ZenGuardTool
+
+
+@pytest.fixture()
+def zenguard_tool() -> ZenGuardTool:
+    if os.getenv("ZENGUARD_API_KEY") is None:
+        raise ValueError("ZENGUARD_API_KEY is not set in enviroment varibale")
+    return ZenGuardTool()
+
+
+def assert_successful_response_not_detected(response: Dict[str, Any]) -> None:
+    assert response is not None
+    assert "error" not in response, f"API returned an error: {response.get('error')}"
+    assert response.get("is_detected") is False, f"Prompt was detected: {response}"
+
+
+def assert_detectors_response(
+    response: Dict[str, Any],
+    detectors: List[Detector],
+) -> None:
+    assert response is not None
+    for detector in detectors:
+        common_response = next(
+            (
+                resp["common_response"]
+                for resp in response["responses"]
+                if resp["detector"] == detector.value
+            )
+        )
+        assert (
+            "err" not in common_response
+        ), f"API returned an error: {common_response.get('err')}"  # noqa: E501
+        assert (
+            common_response.get("is_detected") is False
+        ), f"Prompt was detected: {common_response}"  # noqa: E501
+
+
+def test_prompt_injection(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple prompt injection test"
+    detectors = [Detector.PROMPT_INJECTION]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_pii(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple PII test"
+    detectors = [Detector.PII]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_allowed_topics(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple allowed topics test"
+    detectors = [Detector.ALLOWED_TOPICS]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_banned_topics(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple banned topics test"
+    detectors = [Detector.BANNED_TOPICS]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_keywords(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple keywords test"
+    detectors = [Detector.KEYWORDS]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_secrets(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple secrets test"
+    detectors = [Detector.SECRETS]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_toxicity(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple toxicity test"
+    detectors = [Detector.TOXICITY]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_successful_response_not_detected(response)
+
+
+def test_all_detectors(zenguard_tool: ZenGuardTool) -> None:
+    prompt = "Simple all detectors test"
+    detectors = [
+        Detector.ALLOWED_TOPICS,
+        Detector.BANNED_TOPICS,
+        Detector.KEYWORDS,
+        Detector.PII,
+        Detector.PROMPT_INJECTION,
+        Detector.SECRETS,
+        Detector.TOXICITY,
+    ]
+    response = zenguard_tool.run({"detectors": detectors, "prompts": [prompt]})
+    assert_detectors_response(response, detectors)