Updated API for check_list_elements() (#131)

**What changes are proposed in this pull request?**
- I started programming with this function in gtsummary, and it was
cumbersome to perform multi checks in one call to the function, and it
was more difficult to read. So I've updated the function to perform
checks on one named list at a time.

**Reference GitHub issue associated with pull request.** _e.g., 'closes
#1'_
closes #124


--------------------------------------------------------------------------------

Reviewer Checklist (if item does not apply, mark is as complete)

- [ ] Ensure all package dependencies are installed:
`devtools::install_dev_deps()`
- [ ] PR branch has pulled the most recent updates from master branch:
`usethis::pr_merge_main()`
- [ ] If a bug was fixed, a unit test was added.
- [ ] Run `pkgdown::build_site()`. Check the R console for errors, and
review the rendered website.
- [ ] Code coverage is suitable for any new functions/features:
`devtools::test_coverage()`
- [ ] `usethis::use_spell_check()` runs with no spelling errors in
documentation

When the branch is ready to be merged:
- [ ] Update `NEWS.md` with the changes from this pull request under the
heading "`# cards (development version)`". If there is an issue
associated with the pull request, reference it in parentheses at the end
update (see `NEWS.md` for examples).
- [ ] Increment the version number using `usethis::use_version(which =
"dev")`
- [ ] Run `usethis::use_spell_check()` again
- [ ] Approve Pull Request
- [ ] Merge the PR. Please use "Squash and merge".

R/ard_continuous.R

@@ -81,13 +81,11 @@ ard_continuous <- function(data,
   )
 
   check_list_elements(
-    statistics = function(x) is.list(x) && is_named(x) && every(x, is.function),
+    x = statistics,
+    predicate = function(x) is.list(x) && is_named(x) && every(x, is.function),
     error_msg =
-      list(
-        statistics =
-          c("Error in the argument {.arg {arg_name}} for variable {.val {variable}}.",
-            "i" = "Value must be a named list of functions."
-          )
+      c("Error in the argument {.arg {arg_name}} for variable {.val {variable}}.",
+        "i" = "Value must be a named list of functions."
       )
   )
 
@@ -152,7 +150,9 @@ ard_continuous <- function(data,
   df_results |>
     dplyr::mutate(context = "continuous") |>
     tidy_ard_column_order() %>%
-    {structure(., class = c("card", class(.)))} # styler: off
+    {
+      structure(., class = c("card", class(.)))
+    }
 }
 
 
@@ -163,7 +163,7 @@ ard_continuous <- function(data,
 #' they do not begin with `"...ard_"` and end with `"..."`
 #'
 #' @param x data frame
-#' @param env environment for error messaging
+#' @param call frame for error messaging
 #' @param exceptions character string of column names to exclude from checks
 #'
 #' @return invisible
@@ -293,19 +293,21 @@ ard_continuous <- function(data,
             x[c("variable", "stat_name")] |>
             dplyr::filter(.data$variable %in% .env$variable) |>
             unique() %>%
-            {stats::setNames(as.list(.[["stat_name"]]), .[["stat_name"]])} # styler: off
+            {
+              stats::setNames(as.list(.[["stat_name"]]), .[["stat_name"]])
+            }
 
           compute_formula_selector(
             data = lst_stat_names,
             x = enlst_arg
           ) %>%
-            # styler: off
-            {dplyr::tibble(
-              variable = variable,
-              stat_name = names(.),
-              "{new_column}" := unname(.)
-            )}
-          # styler: on
+            {
+              dplyr::tibble(
+                variable = variable,
+                stat_name = names(.),
+                "{new_column}" := unname(.)
+              )
+            }
         }
       ) |>
       dplyr::bind_rows()

R/process_selectors.R

@@ -20,9 +20,8 @@
 #' - `compute_formula_selector()`: used in `process_formula_selectors()` to
 #'   evaluate a single argument.
 #'
-#' - `check_list_elements()`: accepts named arguments where the name is a list
-#'   that exists in the env, and the argument value is a predicate function
-#'   used to the values of the list.
+#' - `check_list_elements()`: used to check the class/type/values of the list
+#'   elements, primarily those processed with `process_formula_selectors()`
 #'
 #' @param data (`data.frame`)\cr
 #'   a data frame
@@ -38,14 +37,18 @@
 #'     a function.
 #' @param env (`environment`)\cr
 #'   env to save the results to. Default is the calling environment.
-#' @param x ([`formula-list-selector`][syntax])\cr
-#'   a named list, list of formulas, or a single formula that will be
-#'   converted to a named list.
+#' @param x
+#'  - `compute_formula_selector()`: ([`formula-list-selector`][syntax])\cr
+#'    a named list, list of formulas, or a single formula that will be
+#'    converted to a named list.
+#'  - `check_list_elements()`: (`named list`)\cr
+#'    a named list
+#' @param predicate a predicate function that returns `TRUE` or `FALSE`
 #' @param arg_name (`string`)\cr
 #'   a string with the argument named being processed. Used
 #'   in error messaging. Default is `caller_arg(x)`
 #' @param error_msg (`character`)\cr
-#'   a named list where the list elements are strings that will
+#'   a character vector that will
 #'   be used in error messaging when mis-specified arguments are passed. Elements
 #'   `"{arg_name}"` and `"{variable}"` are available using glue syntax for messaging.
 #' @param strict (`logical` scalar)\cr
@@ -220,23 +223,20 @@ compute_formula_selector <- function(data, x, arg_name = caller_arg(x), env = ca
 
 #' @name process_selectors
 #' @export
-check_list_elements <- function(..., error_msg = list(), env = caller_env()) {
-  dots <- dots_list(...)
-
+check_list_elements <- function(x,
+                                predicate,
+                                error_msg = NULL,
+                                env = rlang::caller_env(),
+                                arg_name = rlang::caller_arg(x)) {
   imap(
-    dots,
-    function(predicate_fn, arg_name) {
-      imap(
-        get(arg_name, envir = env),
-        function(lst_element, variable) {
-          if (!isTRUE(predicate_fn(lst_element))) {
-            msg <-
-              error_msg[[arg_name]] %||%
-              "The value for argument {.arg {arg_name}} and variable {.val {variable}} is not the expected type."
-            cli::cli_abort(message = msg)
-          }
-        }
-      )
+    x,
+    function(lst_element, variable) {
+      if (!isTRUE(predicate(lst_element))) {
+        msg <-
+          error_msg %||%
+          "The value for argument {.arg {arg_name}} and variable {.val {variable}} is not the expected type."
+        cli::cli_abort(message = msg, call = env)
+      }
     }
   )
 

tests/testthat/_snaps/ard_continuous.md

@@ -51,7 +51,7 @@
     Code
       ard_continuous(mtcars, variables = "mpg", statistics = ~ list(mean = "this is a string"))
     Condition
-      Error:
+      Error in `ard_continuous()`:
       ! Error in the argument `statistics` for variable "mpg".
       i Value must be a named list of functions.