Feature: Additional LangGraph nodes coverage
  As a developer
  I want to exercise remaining uncovered branches in langgraph nodes
  So that code coverage for nodes.py increases

  Scenario: Conversation history handles empty messages
    Given a node with default history limits
    When I prepare the conversation history for empty input
    Then it should return empty history without truncation

  Scenario: Conversation history falls back on invalid limits
    Given a node with invalid history metadata and two messages
    When I prepare the conversation history with invalid limits
    Then it should return full history without truncation

  Scenario: Agent node without configured agent returns failure metadata 
    Given an agent node without an agent configured
    When I execute the node expecting an agent configuration error
    Then the result should include failed_node and error text


  Scenario: Agent receives empty input when no messages exist
    Given an agent node with no prior messages
    When I execute the agent node with empty history
    Then the agent should receive empty input and track node metadata

  Scenario: Agent merges nested metadata context and flags truncation
    Given an agent node with nested metadata context and long history
    When I execute the agent node with nested context
    Then the agent context should merge nested values and mark truncation

  Scenario: Agent error path captures processing failures
    Given an agent node whose handler raises an exception
    When I execute the failing agent node
    Then the agent response should contain the error string

  Scenario: Function node retries and reports missing function
    Given a function node missing a target with retry policy
    When I execute the function node with retries
    Then it should report failure after retries