tests/testthat/test-bootstrap.R

In weightflow: Declarative API for Staged Survey Weights

test_that("bootstrap_weights returns a replicate matrix of the right shape", {
  spec <- weighting_spec(sample_survey, base_weights = pw) |>
    step_calibrate(method = "raking",
                   margins = list(region = c(table(population$region))))
  boot <- bootstrap_weights(spec, replicates = 15, strata = "region",
                            psu = "psu", seed = 7, progress = FALSE)
  expect_s3_class(boot, "weightflow_boot")
  expect_equal(dim(boot$replicates), c(nrow(sample_survey), 15))
  expect_equal(length(boot$weights), nrow(sample_survey))
})

test_that("bootstrap estimates have positive standard errors", {
  spec <- weighting_spec(sample_survey, base_weights = pw) |>
    step_nonresponse(respondent = responded, method = "weighting_class",
                     by = "region") |>
    step_calibrate(method = "raking",
                   margins = list(region = c(table(population$region))))
  boot <- bootstrap_weights(spec, replicates = 20, strata = "region",
                            psu = "psu", seed = 11, progress = FALSE)
  # Use a continuous outcome: its weighted mean is not pinned by the margins,
  # so it genuinely varies across replicates (unlike a calibration-implied total).
  est <- boot_mean(boot, "income")
  expect_true(est$se > 0)
  expect_true(est$ci_lower < est$estimate && est$estimate < est$ci_upper)
})

test_that("a single-PSU stratum is handled with a warning, not an error", {
  d <- sample_survey
  d$region <- as.character(d$region)
  d$region[1] <- "Solo"; d$psu[1] <- -999          # a lone PSU in its own stratum
  spec <- weighting_spec(d, base_weights = pw)
  expect_warning(
    bootstrap_weights(spec, replicates = 5, strata = "region", psu = "psu",
                      seed = 3, progress = FALSE),
    "single PSU")
})

test_that("collect_replicate_weights returns point + replicate columns", {
  spec <- weighting_spec(sample_survey, base_weights = pw) |>
    step_calibrate(method = "raking",
                   margins = list(region = c(table(population$region))))
  boot <- bootstrap_weights(spec, replicates = 12, strata = "region",
                            psu = "psu", seed = 5, progress = FALSE)
  df <- collect_replicate_weights(boot)
  expect_true(all(df$.weight > 0))
  expect_equal(sum(grepl("^rep_", names(df))), 12)
  expect_equal(attr(df, "R"), 12)
  expect_equal(nrow(df), sum(boot$weights > 0))
})