Add check for 0 dimensions when converting to Seurat (#393)

* Add check for 0 dimensions to as_Seurat()

* Add test for converting 0 dim AnnData to Seurat

Author: lazappi

R/as_Seurat.R

@@ -145,6 +145,16 @@ as_Seurat <- function(
     )
   }
 
+  if (any(dim(adata) == 0)) {
+    cli_abort(c(
+      paste(
+        "{.arg adata} must have non-zero dimensions in both axes",
+        "to be converted to a {.cls Seurat} object"
+      ),
+      "i" = "Dimensions are: [{adata$n_obs()}, {adata$n_vars()}]"
+    ))
+  }
+
   object_metadata_mapping <- get_mapping(
     object_metadata_mapping,
     .as_Seurat_guess_object_metadata,

tests/testthat/test-as_Seurat.R

@@ -179,3 +179,12 @@ test_that("as_Seurat works with unnamed mappings", {
     )
   )
 })
+
+test_that("as_Seurat works with a 0 dim AnnData", {
+  adata <- AnnData(X = as(matrix(nrow = 10, ncol = 0), "dgCMatrix"))
+
+  expect_error(
+    adata$as_Seurat(layers_mapping = c(counts = NA)),
+    "must have non-zero dimensions"
+  )
+})