@tdd_issue @tdd_issue_10496
Feature: AutoDebug node functions must not mutate state in-place
  As a LangGraph developer
  I want AutoDebug node functions to return new state dicts
  So that the LangGraph node contract is respected and state isolation is maintained

  Background:
    Given the auto debug state mutation module is imported

  Scenario: _analyze_error does not mutate the original state object
    Given an auto debug agent for mutation testing
    And an initial auto debug state for mutation testing
    When I call _analyze_error and capture the result
    Then the returned state should be a different object from the input state
    And the original state messages list should be unchanged

  Scenario: _analyze_error returns expected keys in partial state dict
    Given an auto debug agent for mutation testing
    And an initial auto debug state for mutation testing
    When I call _analyze_error and capture the result
    Then the returned state must contain key "messages"
    And the analyze_error update should contain non-empty LLM content

  Scenario: _generate_fix does not mutate the original state object
    Given an auto debug agent for mutation testing
    And a state with an error analysis for mutation testing
    When I call _generate_fix and capture the result
    Then the returned state should be a different object from the input state
    And the original state current_fix should be unchanged

  Scenario: _generate_fix returns expected keys in partial state dict
    Given an auto debug agent for mutation testing
    And a state with an error analysis for mutation testing
    When I call _generate_fix and capture the result
    Then the returned state must contain key "current_fix"
    And the generated fix should contain the LLM JSON content

  Scenario: _validate_fix does not mutate the original state object
    Given an auto debug agent for mutation testing
    And a state with a current fix for mutation testing
    When I call _validate_fix and capture the result
    Then the returned state should be a different object from the input state
    And the original state fix_validated should be unchanged

  Scenario: _validate_fix (invalid) returns expected keys in partial state dict
    Given an auto debug agent for mutation testing
    And a state with a current fix and invalid validation for mutation testing
    When I call _validate_fix and capture the result
    Then the returned state must contain key "fix_validated"
    And the returned state must contain key "attempted_fixes"
    And the invalid validation result should come from the LLM JSON content

  Scenario: _validate_fix with valid fix consumes LLM JSON content
    Given an auto debug agent for mutation testing
    And a state with a current fix for mutation testing
    When I call _validate_fix and capture the result
    Then the returned state must contain key "fix_validated"
    And the validation result should come from the LLM JSON content

  Scenario: _validate_fix with invalid fix does not mutate attempted_fixes in-place
    Given an auto debug agent for mutation testing
    And a state with a current fix and invalid validation for mutation testing
    When I call _validate_fix and capture the result
    Then the returned state should be a different object from the input state
    And the original state attempted_fixes list should be unchanged

  Scenario: _finalize does not mutate the original state object
    Given an auto debug agent for mutation testing
    And a state ready for finalization for mutation testing
    When I call _finalize and capture the result
    Then the returned state should be a different object from the input state
    And the original state result should be unchanged

  Scenario: _finalize returns expected keys in partial state dict
    Given an auto debug agent for mutation testing
    And a state ready for finalization for mutation testing
    When I call _finalize and capture the result
    Then the returned state must contain key "result"