fix (qp_dilute): always return data.frame

R/utils.R

@@ -37,7 +37,7 @@ make_pipette_vol <- function(x) {
 #' @param quiet Logical. If FALSE, will warn when dilution is impossible to do
 #'   without concentrating sample.
 #'
-#' @return a named list, with `sample_to_add` as the volume of sample to add,
+#' @return a data.frame, with `sample_to_add` as the volume of sample to add,
 #'   and `add_to` as the volume to dilute the sample into.
 #'
 #' @examples
@@ -52,6 +52,6 @@ dilute <- function(c1,
   v1 <- (c2 * v2) / c1
   x <- data.frame(sample_to_add = v1, add_to = v2 - v1)
   if (round_for_pipettes)
-    x <- apply(x, 2, make_pipette_vol)
-  x
+    x <- apply(x, 2, make_pipette_vol, simplify = FALSE)
+  as.data.frame(x)
 }

tests/testthat/test-qp_dilute.R

@@ -1,7 +1,3 @@
-test_that("multiplication works", {
-  expect_equal(2 * 2, 4)
-})
-
 test_that("length_is_recyclable works", {
   expect_true(length_is_recyclable(1, iris[1, ]))
   expect_true(length_is_recyclable(1, iris[1:2, ]))
@@ -36,3 +32,11 @@ test_that("NULL target_conc uses lowest concentration", {
   expect_equal(out$sample_to_add, c(6, 3, 2, 1.5))
   expect_equal(out$add_to, c(-4, -1, 0, 0.5))
 })
+
+test_that("output type same regardless of input len", {
+  short <- data.frame(.pred_conc = 1) |>
+    qp_dilute(target_conc = 1, target_vol = 2)
+  long <- data.frame(.pred_conc = c(1, 2)) |>
+    qp_dilute(target_conc = 1, target_vol = 2)
+  expect_equal(class(short), class(long))
+})