@phase1 @domain @unit_of_work @uow_coverage_boost
Feature: UnitOfWork coverage boost for uncovered code paths
  As a developer maintaining the UnitOfWork infrastructure
  I want thorough coverage of engine creation, checkpoint repository, and refresh
  So that all code paths in unit_of_work.py are exercised

  # ---------------------------------------------------------------------------
  # Engine creation: non-SQLite URL (lines 90-93)
  # ---------------------------------------------------------------------------

  @uow_non_sqlite_engine
  Scenario: UnitOfWork creates engine for non-SQLite database URL
    Given a UnitOfWork configured with a non-SQLite database URL
    When I access the engine property with mocked create_engine
    Then the engine should be created via the non-SQLite code path
    And the engine should not use SQLite-specific connect_args

  # ---------------------------------------------------------------------------
  # Engine creation: fresh in-memory SQLite not yet cached (lines 71-76)
  # ---------------------------------------------------------------------------

  @uow_fresh_memory_engine
  Scenario: UnitOfWork creates new in-memory engine when cache is empty
    Given the in-memory engine cache is cleared
    And a UnitOfWork configured with an in-memory SQLite URL
    When I access the in-memory engine property with mocked migrations
    Then a new in-memory engine should be created and cached
    And the cached engine should use SERIALIZABLE isolation

  # ---------------------------------------------------------------------------
  # Checkpoint repository access (lines 244-248)
  # ---------------------------------------------------------------------------

  @uow_checkpoints_repo
  Scenario: UnitOfWorkContext exposes checkpoints repository
    Given a UnitOfWorkContext backed by a mock session
    When I access the checkpoints repository from the context
    Then the checkpoints repository should be a CheckpointRepository instance

  @uow_checkpoints_repo_cached
  Scenario: UnitOfWorkContext caches checkpoints repository on repeated access
    Given a UnitOfWorkContext backed by a mock session
    When I access the checkpoints repository from the context twice
    Then both accesses should return the same CheckpointRepository instance

  # ---------------------------------------------------------------------------
  # refresh() method (line 312)
  # ---------------------------------------------------------------------------

  @uow_refresh_entity
  Scenario: UnitOfWorkContext.refresh delegates to session refresh
    Given a UnitOfWorkContext backed by a mock session
    When I call refresh with a dummy entity
    Then session.refresh should have been called with that entity

  # ---------------------------------------------------------------------------
  # Non-SQLite engine options verification (lines 90-93)
  # ---------------------------------------------------------------------------

  @uow_non_sqlite_engine_options
  Scenario: Non-SQLite engine uses default options without isolation_level override
    Given a UnitOfWork configured with a postgresql-style database URL
    When I trigger engine creation with mocked dependencies
    Then create_engine should have been called without isolation_level
    And create_engine should have been called with future=True

  # ---------------------------------------------------------------------------
  # In-memory engine cache hit vs miss (lines 70-78)
  # ---------------------------------------------------------------------------

  @uow_memory_engine_cache_hit
  Scenario: UnitOfWork reuses cached in-memory engine on second instantiation
    Given the in-memory engine cache is cleared
    And a first UnitOfWork has already created an in-memory engine
    When a second UnitOfWork accesses its engine property
    Then the second engine should be the same object as the first
