bugfix on empty data. closes #112

qfes · Jan 31, 2024 · d416b33 · d416b33
1 parent 47b7fdc
commit d416b33
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Showing 4 changed files with 34 additions and 5 deletions.
diff --git a/R/geometry.R b/R/geometry.R
@@ -94,9 +94,12 @@ interleave_xy <- function(xy, dims = "xy") {
 stack_xy <- function(xy, dims = "xy") {
   xy_dims <- unclass(xy)
   # add / remove z
-  xy_dims$z <- if (dims == "xyz" || dims == "XYZ") xy_dims$z %??% 0
-
-  cbind(xy_dims$x, xy_dims$y, xy_dims$z)
+  # NOTE: length-0 z isn't dropped when x and y are length-0
+  if (dims == "xyz" || dims == "XYZ") {
+    cbind(xy_dims$x, xy_dims$y, xy_dims$z %??% 0)
+  } else {
+    cbind(xy_dims$x, xy_dims$y)
+  }
 }
 
 

diff --git a/R/layer_table.R b/R/layer_table.R
@@ -50,7 +50,7 @@ deckgl_table <- function(object, dims = "xy", ...) {
     other_cols <- vctrs::vec_slice(other_cols, feature_sizes$feature_id)
   }
 
-  n_features <- sum(feature_sizes$n_geom %??% nrow(data))
+  n_features <- sum(feature_sizes$n_geom %||% nrow(data))
   list(
     # number of features
     length = jsonlite::unbox(n_features),
@@ -106,7 +106,7 @@ deckgl_geom <- function(coords, dims = "xy", ...) {
   # optimised path for all length = 1 geometries
   # row-major matrix is equivalent to, but
   # simpler and faster to serialise than a list of coords
-  if (max(geom_runs$size) <= 1L) {
+  if (max(geom_runs$size, 0L) <= 1L) {
     return(stack_xy(coords$xy, dims))
   }
 

diff --git a/R/utils.R b/R/utils.R
@@ -69,6 +69,10 @@ n_unique <- function(x, na_rm = FALSE) {
 
 vec_runs <- function(x) {
   size <- vctrs::vec_run_sizes(x)
+  if (vctrs::vec_is_empty(size)) {
+    return (vctrs::new_data_frame(list(loc = integer(), size = integer())))
+  }
+
   len <- length(size)
   loc <- cumsum(vctrs::vec_c(1L, size[seq_len(len - 1L)]))
   vctrs::new_data_frame(list(loc = loc, size = size))

diff --git a/tests/testthat/test-layer_table.R b/tests/testthat/test-layer_table.R
@@ -407,3 +407,25 @@ test_that("deckgl_table works for multipolygons", {
     )
   )
 })
+
+test_that("deckgl_table works for empty data frames", {
+  expect_identical(
+    deckgl_table(vctrs::data_frame()),
+    list(length = jsonlite::unbox(0L), lengths = NULL, columns = list())
+  )
+
+  expect_identical(
+    deckgl_table(vctrs::data_frame(foo = integer())),
+    list(length = jsonlite::unbox(0L), lengths = NULL, columns = list(foo = integer()))
+  )
+
+  expect_equal(
+    deckgl_table(vctrs::data_frame(point = wk::wkt("POINT EMPTY"))),
+    list(length = jsonlite::unbox(0L), lengths = NULL, columns = list(point = cbind(double(), double())))
+  )
+
+  expect_identical(
+    deckgl_table(vctrs::data_frame(point = wk::wkt("POINT EMPTY"), foo = integer())),
+    list(length = jsonlite::unbox(0L), lengths = NULL, columns = list(point = cbind(double(), double()), foo = integer()))
+  )
+})