Summary

Improves the task handler validation logic in A2AServerBuilder to provide more flexible configuration while maintaining proper validation based on agent capabilities.

Problem

The previous validation logic was too strict - it always required a background task handler to be configured, even when streaming was enabled. This prevented valid configurations where only a streaming handler was needed.

Solution

The validation now follows a three-step approach:

1. Check if at least one handler exists: First validates that either a polling or streaming task handler is configured
2. Validate streaming requirements: If streaming is enabled in agent capabilities, ensure a streaming handler is configured
3. Validate background requirements: If streaming is not enabled, ensure a background/polling handler is configured

Changes

server/server_builder.go:322-342

• First checks if both handlers are nil → returns general error message
• Then checks streaming-specific requirements
• Finally checks background-specific requirements
• Provides clear, actionable error messages for each case

server/server_builder_test.go:431

• Updated test assertion to expect the new general error message when no handlers are configured

Benefits

• ✅ Allows streaming-only configurations when appropriate
• ✅ Allows background-only configurations when streaming is disabled
• ✅ Provides clear, context-specific error messages
• ✅ Maintains backward compatibility with existing code

Test Plan

All existing tests pass, including:

• TestA2AServerBuilder_Build_RequiresTaskHandlers - validates all error cases
• Tests for streaming-only and background-only configurations
• Tests for invalid configurations

🤖 Generated with Claude Code