library(survival)

test_that("kmest: estimate and standard error", {
  df1 <- kmest(aml, stratum="x", time="time", event="status",
               conftype="none")
  
  df2 <- summary(survfit(Surv(time, status) ~ x, data=aml, 
                         conf.type="none"))
  
  expect_equal(df1$survival, df2$surv)
  expect_equal(df1$stderr, df2$std.err)
})


test_that("kmest: confidence interval", {
  for (conftype in c("plain", "log", "log-log", "arcsin")) {
    df1 <- kmest(aml, stratum="x", time="time", event="status",
                 conftype=conftype)
    
    df2 <- summary(survfit(Surv(time, status) ~ x, data=aml, 
                           conf.type=conftype))
    
    expect_equal(df1$lower, df2$lower)
    expect_equal(df1$upper, df2$upper)  
  }
})