Document 'rasters' type as char/list

R/stack_rasters.R

@@ -5,12 +5,12 @@
 #' to create and does not require much space, but does require the input rasters
 #' not be moved or altered. Run
 #' `sf::gdal_utils("warp", output_filename, "some_path.tif")` to turn the output
-#' VRT into a standalone TIF file.
+#' VRT into a standalone TIFF file.
 #'
-#' @param rasters A list of rasters to combine into a single multi-band raster,
-#' either as SpatRaster objects from [terra::rast()] or character file paths
-#' to files that can be read by [terra::rast()]. Rasters will be "stacked" upon
-#' one another, preserving values. They must share CRS.
+#' @param rasters A list or character vector of file paths to rasters to combine
+#' into a single multi-band raster. Files will be read by [terra::rast()].
+#' Rasters will be "stacked" upon one another, preserving values.
+#' They must share a CRS.
 #' @param output_filename The location to save the final "stacked" raster. Must be
 #' a VRT file.
 #' @inheritParams rlang::args_dots_empty
@@ -52,6 +52,14 @@ stack_rasters <- function(rasters,
                           band_names) {
   rlang::check_dots_empty()
 
+  tryCatch(
+    check_type_and_length(rasters = list()),
+    error = function(e) check_type_and_length(
+      rasters = character(),
+      call = rlang::caller_env(4)
+    )
+  )
+
   out_dir <- dirname(output_filename)
 
   if (!(reference_raster %in% seq_along(rasters) ||

tests/testthat/_snaps/stack_rasters.md

@@ -0,0 +1,9 @@
+# stack_rasters fails when rasters are not character vectors
+
+    Code
+      stack_rasters(r1)
+    Condition
+      Error in `stack_rasters()`:
+      ! Some input arguments weren't the right class or length:
+      * rasters should be a character, but is a SpatRaster.
+

tests/testthat/test-stack_rasters.R

@@ -87,3 +87,11 @@ test_that("stack_rasters fails when rasters don't share a CRS", {
     class = "rsi_multiple_crs"
   )
 })
+
+test_that("stack_rasters fails when rasters are not character vectors", {
+  r1 <- terra::rast(matrix(rnorm(100), 10))
+  expect_snapshot(
+    stack_rasters(r1),
+    error = TRUE
+  )
+})