test_that("merge example", {
  # example from original dsr package
  # An example of calculating directly standardized rates
  # Data from Table 1, Page 132 of Schoenbach (2000)

  # State specific death counts and fu

  # US standard population
  df_ref  <- data.frame(age_group =c('0-14','15-24','25-44','45-64','65-80'),
                        pop=c(23961000,15420000,21353000,19601000,10685000))

  expect_no_error(my_results <- mergeAgeGroups(df_ref, newGroups = c("0-24", "25-64", "65-80")))
})

test_that("age group format error", {

  df_ref  <- data.frame(age_group = c('0-14','15-24','25-44','45-64','65-80'),
                        pop = c(23961000,15420000,21353000,19601000,10685000))

  # Directly Standardized Rates (per 1000) - 95% CI's using the gamma method
  expect_error(my_results <- mergeAgeGroups(df_ref, c("0-15", "16-64", "65-80"),
                                            age = "age_group",
                                            pop = "pop"))

})

test_that("refdata is dataframe", {

  df_ref  <- list(pop = c(23961000,15420000,21353000,19601000,10685000),
                  age = c(0,19,32,48,62))

  # Directly Standardized Rates (per 1000) - 95% CI's using the gamma method
  expect_error(my_results <- mergeAgeGroups(df_ref, newGroups = c("0-14", "15-64", "65-80")))

})


test_that("newGroups is vector", {

  df_ref  <- data.frame(age_group = c('0-14','15-24','25-44','45-64','65-80'),
                        pop = c(23961000,15420000,21353000,19601000,10685000))

  # Directly Standardized Rates (per 1000) - 95% CI's using the gamma method
  expect_error(my_results <- mergeAgeGroups(df_ref, newGroups = data.frame("0-14", "15-64", "65-80")))

})

test_that("age and pop columns in data frame", {

  df_ref  <- data.frame(pop = c(23961000,15420000,21353000,19601000,10685000))

  # Directly Standardized Rates (per 1000) - 95% CI's using the gamma method
  expect_error(my_results <- mergeAgeGroups(df_ref, newGroups = c("0-15", "16-64", "65-80")))

  df_ref  <- data.frame(age_group = c('0-14','15-24','25-44','45-64','65-80'))

  # Directly Standardized Rates (per 1000) - 95% CI's using the gamma method
  expect_error(my_results <- mergeAgeGroups(df_ref, newGroups = c("0-15", "16-64", "65-80")))

})

test_that("no NA values", {

  df_ref  <- data.frame(age_group = c('0-14','15-24','25-44','45-64','65+'),
                        pop = c(23961000,15420000,21353000,19601000,10685000))

  # Directly Standardized Rates (per 1000) - 95% CI's using the gamma method
  expect_error(my_results <- mergeAgeGroups(df_ref, newGroups = c("0-15", "16-64", "65-80")))

})

test_that("strata works", {

  df_ref  <- data.frame(age_group = rep(c('0-14','15-24','25-44','45-64','65-80'), 2),
                        pop = rep(c(23961000,15420000,21353000,19601000,10685000),2),
                        sex = rep(c("Male", "Female"),5))

  expect_no_error(my_results <- mergeAgeGroups(df_ref,
                                               newGroups = c("0-24", "25-64", "65-80"),
                                               strata = "sex"))

  expect_error(my_results <- mergeAgeGroups(df_ref,
                                               newGroups = c("0-24", "25-64", "65-80"),
                                               strata = "country"))

})

test_that("age group checks", {

  df_ref  <- data.frame(age_group = rep(c('0-14','15-24','25-44','45-64','65+'), 2),
                        pop = rep(c(23961000,15420000,21353000,19601000,10685000),2),
                        sex = rep(c("Male", "Female"),5))




  expect_error(my_results <- mergeAgeGroups(df_ref,
                                            newGroups = c("0-24", "25-64", "65-80"),
                                            strata = "sex"))
})

test_that("missing event", {

  df_ref  <- data.frame(age_group = rep(c('0-14','15-24','25-44','45-64','65+'), 2),
                        pop = rep(c(23961000,15420000,21353000,19601000,10685000),2),
                        sex = rep(c("Male", "Female"),5))




  expect_error(my_results <- mergeAgeGroups(df_ref,
                                            newGroups = c("0-24", "25-64", "65-80"),
                                            strata = "sex",
                                            event = "death"))
})