feat(epi_slide_opt): adjust [.]new_col_name = error guidance

R/slide.R

@@ -646,7 +646,7 @@ epi_slide_opt <- function(
   if ("new_col_name" %in% provided_args || ".new_col_name" %in% provided_args) {
     cli::cli_abort(
       "epi_slide_opt: the argument `new_col_name` is not supported for `epi_slide_opt`. If you want to customize
-      the output column names, use `dplyr::rename` after the slide.",
+      the output column names, use `.prefix =`, `.suffix =`, or `.new_col_**names** =`.",
       class = "epiprocess__epi_slide_opt__new_name_not_supported"
     )
   }

R/utils.R

@@ -1137,7 +1137,7 @@ time_delta_to_n_steps <- function(time_delta, time_type) {
       week = "weeks",
       cli_abort("difftime objects not supported for time_type {format_chr_with_quotes(time_type)}")
     )
-    units(time_delta) <- output_units # converts number accordingly, doesn't just set attr
+    units(time_delta) <- output_units # converts number to represent same duration; not just attr<-
     n_steps <- vec_data(time_delta)
     if (!is_bare_integerish(n_steps)) {
       cli_abort("`time_delta` did not appear to contain only integerish numbers
@@ -1164,7 +1164,7 @@ time_delta_to_n_steps <- function(time_delta, time_type) {
 time_type_unit_abbrs <- c(
   day = "d",
   week = "w",
-  yearmon = "m"
+  yearmonth = "m"
 )
 
 time_type_unit_abbr <- function(time_type) {

tests/testthat/test-epi_slide.R

@@ -755,3 +755,61 @@ test_that("no dplyr warnings from selecting multiple columns", {
   )
   expect_equal(multi_slid_select, multi_slid)
 })
+
+test_that("epi_slide_opt output naming features", {
+  multi_columns <- dplyr::bind_rows(
+    dplyr::tibble(geo_value = "ak", time_value = test_date + 1:200, value = 1:200, value2 = -1:-200),
+    dplyr::tibble(geo_value = "al", time_value = test_date + 1:5, value = -(1:5), value2 = 1:5)
+  ) %>%
+    as_epi_df() %>%
+    group_by(geo_value)
+  multi_columns_weekly <- dplyr::bind_rows(
+    dplyr::tibble(geo_value = "ak", time_value = test_date + 7*(1:200), value = 1:200, value2 = -1:-200),
+    dplyr::tibble(geo_value = "al", time_value = test_date + 7*(1:5), value = -(1:5), value2 = 1:5)
+  ) %>%
+    as_epi_df() %>%
+    group_by(geo_value)
+  yearmonthly <-
+    tibble::tibble(geo_value = 1,
+                   time_value = tsibble::make_yearmonth(2000, 1) + 1:30 - 1,
+                   value = 1:30 %% 2 == 0) %>%
+    as_epi_df() %>%
+    group_by(geo_value)
+
+  # Auto-naming:
+  # * Changing .f and .window_size:
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, frollmean, .window_size = 14) %>% names(),
+    c(names(multi_columns), "value2_14dav")
+  )
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_mean, .window_size = as.difftime(14, units = "days")) %>% names(),
+    c(names(multi_columns), "value2_14dav")
+  )
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_sum, .window_size = Inf) %>% names(),
+    c(names(multi_columns), "value2_running_sum")
+  )
+  # * Changing .f and .align:
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_min, .window_size = 14, .align = "center") %>% names(),
+    c(names(multi_columns), "value2_14dcmin")
+  )
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_max, .window_size = 14, .align = "left") %>% names(),
+    c(names(multi_columns), "value2_14dlmax")
+  )
+  # * Changing .f, time_type, .window_size:
+  expect_equal(
+    multi_columns_weekly %>% epi_slide_opt(value2, slide_prod, .window_size = 2) %>% names(),
+    c(names(multi_columns_weekly), "value2_2wprod")
+  )
+  expect_equal(
+    multi_columns_weekly %>% epi_slide_opt(value2, slide_prod, .window_size = as.difftime(2, units = "weeks")) %>% names(),
+    c(names(multi_columns_weekly), "value2_2wprod")
+  )
+  expect_equal(
+    yearmonthly %>% epi_slide_opt(value, slide_any, .window_size = 3) %>% names(),
+    c(names(yearmonthly), "value_3many") # not the best name, but super unlikely anyway
+  )
+})