testthat::test_that(
  desc = "Test that the convinience functions calibrates the data correctly",
  code = {

    testthat::expect_false(
      setequal(
        zoo::index(FGIndex),
        zoo::index(BTC)
      )
    )

    # 2) to align the indices,
    # we use the convincience functions
    # by splitting the FGI by the BTC index.
    FGIndex <- split_window(
      xts = FGIndex,
      by  = zoo::index(BTC),

      # Remove upper bounds of the
      # index to avoid overlap between
      # the dates.
      #
      # This ensures that the FGI is split
      # according to start of each weekly
      # BTC candle
      bounds = 'upper'
    )

    # 3) as splitWindow returns a list
    # it needs to passed into calibrateWindow
    # to ensure comparability
    FGIndex <- calibrate_window(
      list = FGIndex,

      # As each element in the list can include
      # more than one row, each element needs to be aggregated
      # or summarised.
      #
      # using xts::first gives the first element
      # of each list, along with its values
      FUN  = xts::first
    )


    # 3) check if candles aligns
    # accordingly
    testthat::expect_equal(
      zoo::index(BTC),
      zoo::index(FGIndex)
    )

  }
)