--- a
+++ b/tests/testthat/test-coordsystem.R
@@ -0,0 +1,35 @@
+# Testing functions of manipulating images ####
+test_that("coords_system", {
+  
+  # get data
+  data("visium_data")
+  data("xenium_data")
+  
+  # get coordinate systems
+  vrSpatialNames(visium_data)
+  vrSpatialNames(visium_data[["Assay1"]])
+  vrSpatialNames(visium_data, assay = "Assay1")
+  vrSpatialNames(visium_data, assay = "all")
+  
+  # set coordinate systems
+  vrMainSpatial(visium_data[["Assay1"]]) <- "main"
+  vrMainSpatial(visium_data[["Assay1"]]) <- c("main", "H&E")
+  expect_error(vrMainSpatial(visium_data[["Assay1"]]) <- c("main", "DAPI"))
+  expect_error(vrMainSpatial(visium_data[["Assay1"]]) <- c("main2", "H&E"))
+  vrMainSpatial(visium_data) <- c("main", "H&E")
+  vrMainSpatial(visium_data, assay = "Assay1") <- c("main", "H&E")
+  
+  # set coordinate system when ignore is specified
+  expect_warning(vrMainSpatial(visium_data[["Assay1"]], ignore = TRUE) <- "main2")
+  expect_error(vrMainSpatial(visium_data[["Assay1"]], ignore = FALSE) <- "main2")
+  
+  # mergeddata
+  mergeddata <- merge(xenium_data, visium_data, verbose = FALSE)
+  expect_true(nrow(vrSpatialNames(mergeddata, assay = "all")) == 2)
+  vrMainSpatial(mergeddata) <- c("main", "H&E")
+  vrMainAssay(mergeddata) <- "Xenium"
+  expect_error(vrMainSpatial(mergeddata) <- c("main", "H&E"))
+
+  # return
+  expect_equal(1,1L)
+})
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