tests/testthat/test-formula.R

In MultiFrailty: Shared Frailty Regression Models with Inverse Gaussian, Generalized Lindley, and Gamma Frailty Distributions

test_that("multifrailty formula interface works seamlessly with Surv()", {
  set.seed(123)
  df <- data.frame(
    time = rexp(60, rate = 0.1) + 0.1,
    status = sample(c(0, 1), 60, replace = TRUE),
    age = rnorm(60, mean = 50, sd = 10),
    sex = sample(c(0, 1), 60, replace = TRUE)
  )

  fit <- multifrailty(survival::Surv(time, status) ~ age + sex, data = df,
                      baseline = "weibull", frailty = "gamma")

  expect_s3_class(fit, "multifrailty")
  expect_s3_class(fit, "multifrailty_fit")
  expect_equal(fit$n_cov, 2)
  expect_true("age" %in% rownames(fit$coefficients))
  expect_true("sex" %in% rownames(fit$coefficients))
})