--- a
+++ b/tests/testthat/test-subset.R
@@ -0,0 +1,26 @@
+# Testing functions of subsetting ####
+test_that("subset", {
+  
+  # get data
+  data("visium_data")
+  
+  # subset based on assay
+  subset(visium_data, assays = "Assay1")
+  subset(visium_data, assays = "Visium")
+  expect_error(subset(visium_data, assays = "Visium2"))
+  
+  # subset based on samples
+  subset(visium_data, samples = "Anterior1")
+  expect_error(subset(visium_data, samples = "Anterior2"))
+  
+  # subset based on assay
+  subset(visium_data, spatialpoints = c("GTTATATTATCTCCCT-1_Assay1", "GTTTGGGTTTCGCCCG-1_Assay1"))
+  expect_error(subset(visium_data, spatialpoints = c("point")))
+  
+  # subset based on features
+  subset(visium_data, features = c("Map3k19", "Rab3gap1"))
+  expect_error(subset(visium_data, features = c("feature")))
+  
+  # return
+  expect_equal(1,1L)
+})
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