Check for duplicate function definitions

Scans a directory for R files and identifies any function definitions that appear multiple times (by name). This is useful in endpoint analysis pipelines to prevent accidental function redefinitions that could cause unexpected behavior. The check is case-sensitive (i.e., func_name and Func_name are considered distinct).

Usage

check_duplicate_functions(dir)

Arguments

dir

The directory where the custom functions are defined

Value

Run for side-effects. Returns NULL invisibly if no duplicates are found. If duplicate functions are detected, an error is thrown with details about which functions are duplicated.

Examples

if (FALSE) { # \dontrun{
  # Create a temporary directory for demonstration
  tmp_dir <- tempdir()

  # Valid case: no duplicate function names
  writeLines("
    compute_n_subjects <- function(dat, ...) {
      nrow(dat)
    }
  ", file.path(tmp_dir, "stat_functions_1.R"))

  writeLines("
    compute_event_rate <- function(dat, ...) {
      sum(dat$is_event) / nrow(dat)
    }
  ", file.path(tmp_dir, "stat_functions_2.R"))

  # Check passes - no duplicates found
  check_duplicate_functions(tmp_dir)

  # Invalid case: duplicate function names cause error
  writeLines("
    compute_n_subjects <- function(dat, ...) {
      sum(!is.na(dat$id))  # Different implementation
    }
  ", file.path(tmp_dir, "stat_functions_2.R"))

  # This will error with message about "compute_n_subjects" being duplicated
  check_duplicate_functions(tmp_dir)
} # }