testing the step

R/step_adjust_latency.R

@@ -301,7 +301,7 @@ bake.step_adjust_latency <- function(object, new_data, ...) {
     # locf doesn't need to mess with the metadata at all, it just forward-fills the requested columns
     rel_keys <- setdiff(key_colnames(new_data), "time_value")
     unnamed_columns <- object$columns %>% unname()
-    new_data %>%
+    new_data <- new_data %>%
       pad_to_end(rel_keys, object$forecast_date) %>%
       # group_by_at(rel_keys) %>%
       arrange(time_value) %>%

tests/testthat/test-step_adjust_latency.R

@@ -165,6 +165,58 @@ test_that("epi_adjust_latency correctly extends the ahead", {
   expect_equal(length(fit2$fit$fit$fit$coefficients), 6)
 })
 
+test_that("epi_adjust_latency correctly locfs", {
+  r1 <- epi_recipe(x) %>%
+    step_adjust_latency(method = "locf") %>%
+    step_epi_lag(death_rate, lag = c(0, 6, 11)) %>%
+    step_epi_lag(case_rate, lag = c(1, 5)) %>%
+    step_epi_ahead(death_rate, ahead = ahead)
+
+  # directly checking the shifts
+  baked_x <- r1 %>%
+    prep(real_x) %>%
+    bake(real_x)
+  # map each column to its last non-NA value
+  last_dates <- baked_x %>%
+    tidyr::pivot_longer(cols = contains("rate"), values_drop_na = TRUE) %>%
+    group_by(name) %>%
+    summarise(last_date = max(time_value)) %>%
+    arrange(desc(last_date))
+  expect_equal(
+    last_dates,
+    tribble(
+      ~name, ~last_date,
+      "lag_11_death_rate", max_time + 11,
+      "lag_6_death_rate", max_time + 6,
+      "lag_5_case_rate", max_time + 5,
+      "lag_1_case_rate", max_time + 1,
+      "case_rate", max_time,
+      "death_rate", max_time,
+      "lag_0_death_rate", max_time + 0,
+      "ahead_7_death_rate", max_time - 7,
+    )
+  )
+  # we expect a 5-fold repetition of the last values found in the original
+  # epi_df
+  last_real <- real_x %>%
+    group_by(geo_value) %>%
+    arrange(time_value) %>%
+    slice_tail() %>%
+    ungroup() %>%
+    select(case_rate, death_rate) %>%
+    uncount(5)
+  # pulling just the region between the last day and the prediction day
+  filled_values <-
+    baked_x %>%
+    filter(
+      time_value > max(real_x$time_value),
+      time_value <= attributes(real_x)$metadata$as_of
+    ) %>%
+    ungroup() %>%
+    select(case_rate, death_rate)
+  expect_equal(last_real, filled_values)
+})
+
 test_that("epi_adjust_latency extends multiple aheads", {
   aheads <- 1:3
   r3 <- epi_recipe(x) %>%