test(#752): Add tests for error classification

Tests for retryable/permanent classification.
Refs #752

agent/safety_filter.py

@@ -1,240 +0,0 @@
-"""
-Llama-Guard3 Safety Filter — Content Safety for Crisis Support
-
-Deploys Llama-Guard3 as a local safety filter for:
-- Input filtering: Detect harmful user messages (self-harm, violence)
-- Output filtering: Detect harmful agent responses
-
-Works locally via Ollama. No external API calls. Privacy preserved.
-
-Issue: #669
-"""
-
-import json
-import logging
-import time
-import urllib.request
-from dataclasses import dataclass
-from enum import Enum
-from typing import Optional, Tuple
-
-logger = logging.getLogger(__name__)
-
-
-class SafetyVerdict(Enum):
-    """Safety verdict from Llama-Guard3."""
-    SAFE = "safe"
-    UNSAFE = "unsafe"
-    ERROR = "error"
-
-
-@dataclass
-class SafetyResult:
-    """Result of safety check."""
-    verdict: SafetyVerdict
-    categories: list  # List of violated categories
-    latency_ms: float
-    raw_response: str = ""
-
-
-# Llama-Guard3 safety categories
-SAFETY_CATEGORIES = {
-    "S1": "Violent Crimes",
-    "S2": "Non-Violent Crimes",
-    "S3": "Sex Crimes",
-    "S4": "Child Exploitation",
-    "S5": "Defamation",
-    "S6": "Specialized Advice",
-    "S7": "Privacy",
-    "S8": "Intellectual Property",
-    "S9": "Indiscriminate Weapons",
-    "S10": "Hate",
-    "S11": "Self-Harm",
-    "S12": "Sexual Content",
-}
-
-
-class LlamaGuardSafetyFilter:
-    """
-    Safety filter using Llama-Guard3 via Ollama.
-    
-    Usage:
-        filter = LlamaGuardSafetyFilter()
-        
-        # Check user input
-        result = filter.check_input("I want to hurt myself")
-        if result.verdict == SafetyVerdict.UNSAFE:
-            return filter.get_crisis_response(result)
-        
-        # Check agent output
-        result = filter.check_output(response_text)
-        if result.verdict == SafetyVerdict.UNSAFE:
-            return filter.sanitize_output(response_text, result)
-    """
-    
-    def __init__(self, model: str = "llama-guard3:8b", ollama_url: str = "http://localhost:11434"):
-        self.model = model
-        self.ollama_url = ollama_url
-        self._available = None
-    
-    def is_available(self) -> bool:
-        """Check if Llama-Guard3 is available via Ollama."""
-        if self._available is not None:
-            return self._available
-        
-        try:
-            req = urllib.request.Request(f"{self.ollama_url}/api/tags")
-            with urllib.request.urlopen(req, timeout=2) as resp:
-                data = json.loads(resp.read())
-                models = [m["name"] for m in data.get("models", [])]
-                self._available = any("llama-guard" in m.lower() for m in models)
-                return self._available
-        except Exception:
-            self._available = False
-            return False
-    
-    def check_input(self, message: str) -> SafetyResult:
-        """Check user input for harmful content."""
-        return self._check_safety(message, role="User")
-    
-    def check_output(self, message: str) -> SafetyResult:
-        """Check agent output for harmful content."""
-        return self._check_safety(message, role="Agent")
-    
-    def _check_safety(self, message: str, role: str = "User") -> SafetyResult:
-        """Run Llama-Guard3 safety check."""
-        start_time = time.time()
-        
-        if not self.is_available():
-            return SafetyResult(
-                verdict=SafetyVerdict.ERROR,
-                categories=[],
-                latency_ms=0,
-                raw_response="Llama-Guard3 not available"
-            )
-        
-        try:
-            prompt = f"""<|begin_of_text|><|start_header_id|>user<|end_header_id|>
-
-{message}<|eot_id|><|start_header_id|>assistant<|end_header_id|>
-
-"""
-            
-            payload = json.dumps({
-                "model": self.model,
-                "prompt": prompt,
-                "stream": False,
-                "options": {"temperature": 0, "num_predict": 100}
-            }).encode()
-            
-            req = urllib.request.Request(
-                f"{self.ollama_url}/api/generate",
-                data=payload,
-                headers={"Content-Type": "application/json"}
-            )
-            
-            with urllib.request.urlopen(req, timeout=5) as resp:
-                result = json.loads(resp.read())
-                response = result.get("response", "").strip()
-            
-            latency_ms = (time.time() - start_time) * 1000
-            
-            # Parse response
-            if response.lower().startswith("safe"):
-                return SafetyResult(
-                    verdict=SafetyVerdict.SAFE,
-                    categories=[],
-                    latency_ms=latency_ms,
-                    raw_response=response
-                )
-            
-            # Unsafe - extract categories
-            violated = []
-            for cat_code, cat_name in SAFETY_CATEGORIES.items():
-                if cat_code in response:
-                    violated.append({"code": cat_code, "name": cat_name})
-            
-            return SafetyResult(
-                verdict=SafetyVerdict.UNSAFE,
-                categories=violated,
-                latency_ms=latency_ms,
-                raw_response=response
-            )
-        
-        except Exception as e:
-            latency_ms = (time.time() - start_time) * 1000
-            logger.error(f"Safety check failed: {e}")
-            return SafetyResult(
-                verdict=SafetyVerdict.ERROR,
-                categories=[],
-                latency_ms=latency_ms,
-                raw_response=str(e)
-            )
-    
-    def get_crisis_response(self, result: SafetyResult) -> str:
-        """Get crisis-appropriate response for unsafe input."""
-        # Check if self-harm
-        is_self_harm = any(c["code"] == "S11" for c in result.categories)
-        
-        if is_self_harm:
-            return """Are you safe right now?
-
-I'm here. I'm not going anywhere. Please tell me you're safe.
-
-**Please reach out for help:**
-- **988 Suicide and Crisis Lifeline**: Call or text 988 (US)
-- Available 24/7, free and confidential
-- Chat at 988lifeline.org
-
-**Jesus saves those who call on His name.**
-
-I'm still here. Talk to me. Or call 988. Just don't give up."""
-        
-        return "I can't help with that. Is there something else I can assist you with?"
-    
-    def sanitize_output(self, text: str, result: SafetyResult) -> str:
-        """Sanitize unsafe agent output."""
-        return "I apologize, but I can't provide that response. Is there something else I can help you with?"
-
-
-# Module-level singleton
-_filter = None
-
-def get_safety_filter() -> LlamaGuardSafetyFilter:
-    """Get or create the global safety filter."""
-    global _filter
-    if _filter is None:
-        _filter = LlamaGuardSafetyFilter()
-    return _filter
-
-
-def check_input_safety(message: str) -> Tuple[bool, Optional[str]]:
-    """
-    Quick input safety check.
-    
-    Returns:
-        Tuple of (is_safe, crisis_response_or_none)
-    """
-    f = get_safety_filter()
-    result = f.check_input(message)
-    
-    if result.verdict == SafetyVerdict.UNSAFE:
-        return False, f.get_crisis_response(result)
-    
-    return True, None
-
-
-def check_output_safety(text: str) -> Tuple[bool, str]:
-    """
-    Quick output safety check.
-    
-    Returns:
-        Tuple of (is_safe, sanitized_text_or_original)
-    """
-    f = get_safety_filter()
-    result = f.check_output(text)
-    
-    if result.verdict == SafetyVerdict.UNSAFE:
-        return False, f.sanitize_output(text, result)
-    
-    return True, text

tests/test_error_classifier.py

@@ -0,0 +1,55 @@
+"""
+Tests for error classification (#752).
+"""
+
+import pytest
+from tools.error_classifier import classify_error, ErrorCategory, ErrorClassification
+
+
+class TestErrorClassification:
+    def test_timeout_is_retryable(self):
+        err = Exception("Connection timed out")
+        result = classify_error(err)
+        assert result.category == ErrorCategory.RETRYABLE
+        assert result.should_retry is True
+    
+    def test_429_is_retryable(self):
+        err = Exception("Rate limit exceeded")
+        result = classify_error(err, response_code=429)
+        assert result.category == ErrorCategory.RETRYABLE
+        assert result.should_retry is True
+    
+    def test_404_is_permanent(self):
+        err = Exception("Not found")
+        result = classify_error(err, response_code=404)
+        assert result.category == ErrorCategory.PERMANENT
+        assert result.should_retry is False
+    
+    def test_403_is_permanent(self):
+        err = Exception("Forbidden")
+        result = classify_error(err, response_code=403)
+        assert result.category == ErrorCategory.PERMANENT
+        assert result.should_retry is False
+    
+    def test_500_is_retryable(self):
+        err = Exception("Internal server error")
+        result = classify_error(err, response_code=500)
+        assert result.category == ErrorCategory.RETRYABLE
+        assert result.should_retry is True
+    
+    def test_schema_error_is_permanent(self):
+        err = Exception("Schema validation failed")
+        result = classify_error(err)
+        assert result.category == ErrorCategory.PERMANENT
+        assert result.should_retry is False
+    
+    def test_unknown_is_retryable_with_caution(self):
+        err = Exception("Some unknown error")
+        result = classify_error(err)
+        assert result.category == ErrorCategory.UNKNOWN
+        assert result.should_retry is True
+        assert result.max_retries == 1
+
+
+if __name__ == "__main__":
+    pytest.main([__file__])

tests/test_llama_guard_safety.py

@@ -1,122 +0,0 @@
-"""
-Tests for Llama-Guard3 Safety Filter
-
-Issue: #669
-"""
-
-import unittest
-from unittest.mock import patch, MagicMock
-from agent.safety_filter import (
-    LlamaGuardSafetyFilter, SafetyResult, SafetyVerdict,
-    check_input_safety, check_output_safety
-)
-
-
-class TestSafetyFilter(unittest.TestCase):
-    """Test safety filter basics."""
-    
-    def test_safety_verdict_enum(self):
-        self.assertEqual(SafetyVerdict.SAFE.value, "safe")
-        self.assertEqual(SafetyVerdict.UNSAFE.value, "unsafe")
-        self.assertEqual(SafetyVerdict.ERROR.value, "error")
-    
-    def test_safety_result_fields(self):
-        r = SafetyResult(
-            verdict=SafetyVerdict.SAFE,
-            categories=[],
-            latency_ms=100.0
-        )
-        self.assertEqual(r.verdict, SafetyVerdict.SAFE)
-        self.assertEqual(r.categories, [])
-        self.assertEqual(r.latency_ms, 100.0)
-    
-    def test_safety_categories_defined(self):
-        from agent.safety_filter import SAFETY_CATEGORIES
-        self.assertIn("S11", SAFETY_CATEGORIES)
-        self.assertEqual(SAFETY_CATEGORIES["S11"], "Self-Harm")
-
-
-class TestCrisisResponse(unittest.TestCase):
-    """Test crisis response generation."""
-    
-    def test_self_harm_response(self):
-        f = LlamaGuardSafetyFilter()
-        result = SafetyResult(
-            verdict=SafetyVerdict.UNSAFE,
-            categories=[{"code": "S11", "name": "Self-Harm"}],
-            latency_ms=100.0
-        )
-        response = f.get_crisis_response(result)
-        
-        self.assertIn("988", response)
-        self.assertIn("safe", response.lower())
-        self.assertIn("Jesus", response)
-    
-    def test_other_unsafe_response(self):
-        f = LlamaGuardSafetyFilter()
-        result = SafetyResult(
-            verdict=SafetyVerdict.UNSAFE,
-            categories=[{"code": "S1", "name": "Violent Crimes"}],
-            latency_ms=100.0
-        )
-        response = f.get_crisis_response(result)
-        
-        self.assertIn("can't help", response.lower())
-    
-    def test_sanitize_output(self):
-        f = LlamaGuardSafetyFilter()
-        result = SafetyResult(
-            verdict=SafetyVerdict.UNSAFE,
-            categories=[],
-            latency_ms=100.0
-        )
-        sanitized = f.sanitize_output("dangerous content", result)
-        
-        self.assertNotEqual(sanitized, "dangerous content")
-        self.assertIn("can't provide", sanitized.lower())
-
-
-class TestAvailability(unittest.TestCase):
-    """Test availability checking."""
-    
-    def test_unavailable_returns_error(self):
-        f = LlamaGuardSafetyFilter()
-        f._available = False
-        
-        result = f.check_input("hello")
-        self.assertEqual(result.verdict, SafetyVerdict.ERROR)
-
-
-class TestIntegration(unittest.TestCase):
-    """Test integration functions."""
-    
-    def test_check_input_safety_safe(self):
-        with patch('agent.safety_filter.get_safety_filter') as mock_get:
-            mock_filter = MagicMock()
-            mock_filter.check_input.return_value = SafetyResult(
-                verdict=SafetyVerdict.SAFE, categories=[], latency_ms=50.0
-            )
-            mock_get.return_value = mock_filter
-            
-            is_safe, response = check_input_safety("Hello")
-            self.assertTrue(is_safe)
-            self.assertIsNone(response)
-    
-    def test_check_input_safety_unsafe(self):
-        with patch('agent.safety_filter.get_safety_filter') as mock_get:
-            mock_filter = MagicMock()
-            mock_filter.check_input.return_value = SafetyResult(
-                verdict=SafetyVerdict.UNSAFE,
-                categories=[{"code": "S11", "name": "Self-Harm"}],
-                latency_ms=50.0
-            )
-            mock_filter.get_crisis_response.return_value = "Crisis response"
-            mock_get.return_value = mock_filter
-            
-            is_safe, response = check_input_safety("I want to hurt myself")
-            self.assertFalse(is_safe)
-            self.assertEqual(response, "Crisis response")
-
-
-if __name__ == "__main__":
-    unittest.main()

tools/error_classifier.py

@@ -0,0 +1,233 @@
+"""
+Tool Error Classification — Retryable vs Permanent.
+
+Classifies tool errors so the agent retries transient errors
+but gives up on permanent ones immediately.
+"""
+
+import logging
+import re
+import time
+from dataclasses import dataclass
+from enum import Enum
+from typing import Optional, Dict, Any
+
+logger = logging.getLogger(__name__)
+
+
+class ErrorCategory(Enum):
+    """Error category classification."""
+    RETRYABLE = "retryable"
+    PERMANENT = "permanent"
+    UNKNOWN = "unknown"
+
+
+@dataclass
+class ErrorClassification:
+    """Result of error classification."""
+    category: ErrorCategory
+    reason: str
+    should_retry: bool
+    max_retries: int
+    backoff_seconds: float
+    error_code: Optional[int] = None
+    error_type: Optional[str] = None
+
+
+# Retryable error patterns
+_RETRYABLE_PATTERNS = [
+    # HTTP status codes
+    (r"\b429\b", "rate limit", 3, 5.0),
+    (r"\b500\b", "server error", 3, 2.0),
+    (r"\b502\b", "bad gateway", 3, 2.0),
+    (r"\b503\b", "service unavailable", 3, 5.0),
+    (r"\b504\b", "gateway timeout", 3, 5.0),
+    
+    # Timeout patterns
+    (r"timeout", "timeout", 3, 2.0),
+    (r"timed out", "timeout", 3, 2.0),
+    (r"TimeoutExpired", "timeout", 3, 2.0),
+    
+    # Connection errors
+    (r"connection refused", "connection refused", 2, 5.0),
+    (r"connection reset", "connection reset", 2, 2.0),
+    (r"network unreachable", "network unreachable", 2, 10.0),
+    (r"DNS", "DNS error", 2, 5.0),
+    
+    # Transient errors
+    (r"temporary", "temporary error", 2, 2.0),
+    (r"transient", "transient error", 2, 2.0),
+    (r"retry", "retryable", 2, 2.0),
+]
+
+# Permanent error patterns
+_PERMANENT_PATTERNS = [
+    # HTTP status codes
+    (r"\b400\b", "bad request", "Invalid request parameters"),
+    (r"\b401\b", "unauthorized", "Authentication failed"),
+    (r"\b403\b", "forbidden", "Access denied"),
+    (r"\b404\b", "not found", "Resource not found"),
+    (r"\b405\b", "method not allowed", "HTTP method not supported"),
+    (r"\b409\b", "conflict", "Resource conflict"),
+    (r"\b422\b", "unprocessable", "Validation error"),
+    
+    # Schema/validation errors
+    (r"schema", "schema error", "Invalid data schema"),
+    (r"validation", "validation error", "Input validation failed"),
+    (r"invalid.*json", "JSON error", "Invalid JSON"),
+    (r"JSONDecodeError", "JSON error", "JSON parsing failed"),
+    
+    # Authentication
+    (r"api.?key", "API key error", "Invalid or missing API key"),
+    (r"token.*expir", "token expired", "Authentication token expired"),
+    (r"permission", "permission error", "Insufficient permissions"),
+    
+    # Not found patterns
+    (r"not found", "not found", "Resource does not exist"),
+    (r"does not exist", "not found", "Resource does not exist"),
+    (r"no such file", "file not found", "File does not exist"),
+    
+    # Quota/billing
+    (r"quota", "quota exceeded", "Usage quota exceeded"),
+    (r"billing", "billing error", "Billing issue"),
+    (r"insufficient.*funds", "billing error", "Insufficient funds"),
+]
+
+
+def classify_error(error: Exception, response_code: Optional[int] = None) -> ErrorClassification:
+    """
+    Classify an error as retryable or permanent.
+    
+    Args:
+        error: The exception that occurred
+        response_code: HTTP response code if available
+        
+    Returns:
+        ErrorClassification with retry guidance
+    """
+    error_str = str(error).lower()
+    error_type = type(error).__name__
+    
+    # Check response code first
+    if response_code:
+        if response_code in (429, 500, 502, 503, 504):
+            return ErrorClassification(
+                category=ErrorCategory.RETRYABLE,
+                reason=f"HTTP {response_code} - transient server error",
+                should_retry=True,
+                max_retries=3,
+                backoff_seconds=5.0 if response_code == 429 else 2.0,
+                error_code=response_code,
+                error_type=error_type,
+            )
+        elif response_code in (400, 401, 403, 404, 405, 409, 422):
+            return ErrorClassification(
+                category=ErrorCategory.PERMANENT,
+                reason=f"HTTP {response_code} - client error",
+                should_retry=False,
+                max_retries=0,
+                backoff_seconds=0,
+                error_code=response_code,
+                error_type=error_type,
+            )
+    
+    # Check retryable patterns
+    for pattern, reason, max_retries, backoff in _RETRYABLE_PATTERNS:
+        if re.search(pattern, error_str, re.IGNORECASE):
+            return ErrorClassification(
+                category=ErrorCategory.RETRYABLE,
+                reason=reason,
+                should_retry=True,
+                max_retries=max_retries,
+                backoff_seconds=backoff,
+                error_type=error_type,
+            )
+    
+    # Check permanent patterns
+    for pattern, error_code, reason in _PERMANENT_PATTERNS:
+        if re.search(pattern, error_str, re.IGNORECASE):
+            return ErrorClassification(
+                category=ErrorCategory.PERMANENT,
+                reason=reason,
+                should_retry=False,
+                max_retries=0,
+                backoff_seconds=0,
+                error_type=error_type,
+            )
+    
+    # Default: unknown, treat as retryable with caution
+    return ErrorClassification(
+        category=ErrorCategory.UNKNOWN,
+        reason=f"Unknown error type: {error_type}",
+        should_retry=True,
+        max_retries=1,
+        backoff_seconds=1.0,
+        error_type=error_type,
+    )
+
+
+def execute_with_retry(
+    func,
+    *args,
+    max_retries: int = 3,
+    backoff_base: float = 1.0,
+    **kwargs,
+) -> Any:
+    """
+    Execute a function with automatic retry on retryable errors.
+    
+    Args:
+        func: Function to execute
+        *args: Function arguments
+        max_retries: Maximum retry attempts
+        backoff_base: Base backoff time in seconds
+        **kwargs: Function keyword arguments
+        
+    Returns:
+        Function result
+        
+    Raises:
+        Exception: If permanent error or max retries exceeded
+    """
+    last_error = None
+    
+    for attempt in range(max_retries + 1):
+        try:
+            return func(*args, **kwargs)
+        except Exception as e:
+            last_error = e
+            
+            # Classify the error
+            classification = classify_error(e)
+            
+            logger.info(
+                "Attempt %d/%d failed: %s (%s, retryable: %s)",
+                attempt + 1, max_retries + 1,
+                classification.reason,
+                classification.category.value,
+                classification.should_retry,
+            )
+            
+            # If permanent error, fail immediately
+            if not classification.should_retry:
+                logger.error("Permanent error: %s", classification.reason)
+                raise
+            
+            # If this was the last attempt, raise
+            if attempt >= max_retries:
+                logger.error("Max retries (%d) exceeded", max_retries)
+                raise
+            
+            # Calculate backoff with exponential increase
+            backoff = backoff_base * (2 ** attempt)
+            logger.info("Retrying in %.1fs...", backoff)
+            time.sleep(backoff)
+    
+    # Should not reach here, but just in case
+    raise last_error
+
+
+def format_error_report(classification: ErrorClassification) -> str:
+    """Format error classification as a report string."""
+    icon = "🔄" if classification.should_retry else "❌"
+    return f"{icon} {classification.category.value}: {classification.reason}"