Error scenario testing: network failures, timeouts, malformed responses

Description

Comprehensive error handling and edge case testing for network failures and protocol anomalies.

Scenarios to Test

1. Connection Failures

   • Connection refused (service down)
   • Connection timeout (slow/unreachable host)
   • Connection reset by peer
   • DNS resolution failures

2. Protocol Errors

   • Malformed SMTP responses
   • Incomplete LDAP responses
   • DNS answer truncation (TC bit)
   • Invalid TLS certificates

3. Timeout Scenarios

   • Socket timeout during read
   • Subprocess timeout (tool execution > 900s)
   • DNS query timeout
   • Partial response before timeout

4. Resource Constraints

   • Too many open file descriptors
   • Memory exhaustion during parallel execution
   • Thread pool saturation (all workers busy)

Requirements

• Mock network errors using pytest fixtures
• Test graceful degradation
• Verify error logging and reporting
• Ensure framework continues after failures
• Test fallback mechanisms (SMTP → POP3 → IMAP)

Files to Create

• tests/test_error_scenarios.py
• tests/mocks/network_errors.py
• tests/fixtures/malformed_responses.py

Success Criteria

• All network error types handled gracefully
• No uncaught exceptions
• Clear error messages in output
• Framework continues executing other tools on single-tool failure

Create tests/test_error_scenarios.py with pytest fixtures, plus tests/mocks/network_errors.py and tests/fixtures/malformed_responses.py. Start by reviewing the existing test suite and current error-handling paths, then cover the listed network, protocol, timeout, and resource failures. Done means graceful handling, clear reporting, continued execution after individual failures, and verified fallback behavior.