add tests

R/data_expand.R

@@ -8,6 +8,9 @@
 #' @param data A data frame.
 #' @param expand The name of the column that contains the counts of replications
 #' for each row.
+#' @param remove_na Logical, if `TRUE`, missing values (`NA`) in the column
+#' provided in `expand` are removed from the data frame. If `FALSE` and `expand`
+#' contains missing values, the function will throw an error.
 #' @param ... Currently not used.
 #' @inheritParams find_columns
 #'
@@ -65,6 +68,19 @@ data_expand <- function(data,
   # also remove "expand" from "select" string
   select <- setdiff(select, expand)
 
+  # if user doesn't want to remove "NA", but replicates contain "NA",
+  # give informative error here
+  if (!remove_na && anyNA(replicates)) {
+    insight::format_error(
+      "The column provided in `expand` contains missing values, but `remove_na` is set to `FALSE`.",
+      "Please set `remove_na` to `TRUE` or remove the missing values from the data frame."
+    )
+  }
+
+  # remove rows where "expand" is NA
+  data <- data[!is.na(replicates), ]
+  replicates <- replicates[!is.na(replicates)]
+
   # fin
   as.data.frame(do.call(cbind, lapply(data[select], function(variable) {
     unlist(Map(rep, variable, replicates), use.names = FALSE)

tests/testthat/test-data_expand.R

@@ -0,0 +1,35 @@
+test_that("data_expand: simple use case", {
+  data(mtcars)
+  d <- as.data.frame(head(mtcars))
+  out <- data_expand(d, "carb")
+  expect_identical(dim(out), c(13L, 10L))
+  expect_identical(out$disp, c(160, 160, 160, 160, 160, 160, 160, 160, 108, 258, 360, 360, 225))
+  expect_named(out, c("mpg", "cyl", "disp", "hp", "drat", "wt", "qsec", "vs", "am", "gear"))
+
+  d$mpg[5] <- NA
+  out <- data_expand(d, "carb")
+  expect_identical(dim(out), c(13L, 10L))
+  expect_identical(out$mpg, c(21, 21, 21, 21, 21, 21, 21, 21, 22.8, 21.4, NA, NA, 18.1))
+  expect_named(out, c("mpg", "cyl", "disp", "hp", "drat", "wt", "qsec", "vs", "am", "gear"))
+
+  d$carb[3] <- NA
+  out <- data_expand(d, "carb", remove_na = TRUE)
+  expect_identical(dim(out), c(12L, 10L))
+  expect_identical(out$mpg, c(21, 21, 21, 21, 21, 21, 21, 21, 21.4, NA, NA, 18.1))
+  expect_named(out, c("mpg", "cyl", "disp", "hp", "drat", "wt", "qsec", "vs", "am", "gear"))
+
+  out <- data_expand(d, "carb", select = c("disp", "hp"), remove_na = TRUE)
+  expect_identical(dim(out), c(12L, 2L))
+  expect_identical(out$disp, c(160, 160, 160, 160, 160, 160, 160, 160, 258, 360, 360, 225))
+  expect_named(out, c("disp", "hp"))
+})
+
+test_that("data_expand: errors", {
+  data(mtcars)
+  d <- as.data.frame(head(mtcars))
+  expect_error(data_expand(d), regex = "No column")
+  expect_error(data_expand(d, expand = c("mpg", "gear")), regex = "a single string")
+  expect_error(data_expand(d, expand = "geas"), regex = "The column provided")
+  d$carb[3] <- NA
+  expect_error(data_expand(d, "carb"), regex = "missing values")
+})