adjusting onLoad and test suite for winbuilder

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: umap
 Title: Uniform Manifold Approximation and Projection
-Version: 0.2.4.2
+Version: 0.2.5.0
 Authors@R: 
     person("Tomasz", "Konopka", , "[email protected]", role = c("aut", "cre"))
 Author: Tomasz Konopka [aut, cre]

R/umap.R

@@ -18,26 +18,31 @@
 NULL
 
 
-# These lines are required to control access to the umap python module
-#
+# For interfacing with python and "umap-learn"
+#' @importFrom reticulate py_module_available import
+NULL
+
+
 # This implements a "soft" requirement for python and the umap module
 # i.e. the package should work when those components are absent
 # but gain additional functionality when those components are present
 #' interface to umap-learn via reticulate
 #'
 #' @keywords internal
 #' @noRd
-#' @importFrom reticulate py_module_available import
 python.umap = NULL
 .onLoad = function(libname, pkgname) {
-  has.pkg.umap = reticulate::py_module_available("umap")
-  if (has.pkg.umap) {
-    # assignment in parent environment!
+  # this "try" block is necessary because:
+  # a system that python but not umap-learn stops during the test suite
+  # with the following sequence of commands (devtools)
+  # document(); test(); test()
+  # note that test() only fails at second round
+  try({
     python.umap <<- reticulate::import("umap", delay_load=TRUE)
-  }
+  }, silent=TRUE)
 }
 
-
+  
 #' Default configuration for umap 
 #'
 #' A list with parameters customizing a UMAP embedding. Each component of the

tests/testthat/test_python.R

@@ -19,10 +19,16 @@ rownames(d.test) = paste0("Test", seq_len(nrow(d.test)))
 # Only test if umap is available as python package
 
 
-if (reticulate::py_module_available("umap")) {
-  # Note: a more elegant approach with skip() does not seem to work
-  # devtools::test() stops when skip() is invoked
-
+# this "try" block is necessary because:
+# a system that does not have python at all will generate a warning,
+# which can generate a NOTE during R CMD check (winbuilder)
+has.umap.learn = FALSE
+try({
+  has.umap.learn = reticulate::py_module_available("umap")
+}, silent=TRUE)
+
+
+if (has.umap.learn) {  
   # create initial embedding
   u1 = umap(d.train, method="umap-learn", n_neighbors=10)