tests/testthat/test-sim.R

In dymium-org/dymiumCore: A Toolkit for Building a Dynamic Microsimulation Model for Integrated Urban Modelling

test_that("sim works", {
  # create simple models
  birth_model <- list(yes = 0.1, no = 0.9)
  death_model <- list(yes = 0.1, no = 0.9)

  # prepare population data
  ind_data <-
    data.table::copy(toy_individuals) %>%
    .[, .give_birth := "no"]

  # create a World object, a container for all entities and models for simulation
  world <- World$new()
  world$add(x = Individual$new(.data = ind_data, id_col = "pid"))

  # create filters, this is a method for creating functions using `magrittr` and
  # data.table's syntax
  filter_eligible_females <-
    . %>%
    .[sex == "female" & age %between% c(18, 50)]

  filter_alive <-
    . %>%
    .[age != -1]

  microsimulation_pipeline <-
    . %>%
    # ageing
    mutate_entity(
      entity = "Individual",
      age := age + 1L,
      subset = age != -1L
    ) %>%
    # simulate birth decision
    transition(
      entity = "Individual",
      model = birth_model,
      attr = ".give_birth",
      preprocessing_fn = . %>% filter_eligible_females() %>% filter_alive()
    ) %>%
    # add newborns
    add_entity(
      entity = "Individual",
      newdata = toy_individuals[age == 0, ],
      target = .$entities$Individual$get_data()[.give_birth == "yes", .N]
    ) %>%
    # reset the birth decision variable
    mutate_entity(
      entity = "Individual",
      .give_birth := "no",
      subset = age != -1L
    ) %>%
    # simulate deaths
    transition(
      entity = "Individual",
      model = death_model,
      attr = "age",
      values = c(yes = -1L),
      preprocessing_fn = filter_alive
    ) %>%
    # log the total number of alive individuals at the end of the iteration
    add_log(
      desc = "count:Individual",
      value = .$entities$Individual$get_data()[age != -1L, .N]
    )

  n_iters <- 10

  sim(world = world, pipeline = microsimulation_pipeline, n_iters = n_iters, write.error.dump.folder = FALSE)

  expect_equal(world$get_time(), n_iters)

  expect_error(
    sim(world = 1, pipeline = microsimulation_pipeline, n_iters = 10),
    "Assertion on 'world' failed: Must be an R6 class,"
  )
  expect_error(
    sim(world = world, pipeline = microsimulation_pipeline, n_iters = 0),
    "Assertion on 'n_iters' failed: Must be >= 1."
  )
  expect_error(
    sim(world = world, pipeline = 1, n_iters = 10),
    "Assertion on 'pipeline' failed: Must be a function"
  )
})