rules_r: fix binary_image and write tests

binary_image rule has been broken after the flag
incompatible_depset_is_not_iterable was flipped.

This change fixes the implementation and also introduces some tests for
images. In writing these tests, another breakage has been discovered
because of the flag flip of experimental_remap_main_repo. This bug will
be fixed at a later date.

R/container/binary.bzl

@@ -35,7 +35,7 @@ def _binary_layer_impl(ctx):
         directory = "/",
         file_map = {
             _layer_file_path(ctx, f): f
-            for f in ctx.attr.binary[OutputGroupInfo][ctx.attr.layer_type]
+            for f in ctx.attr.binary[OutputGroupInfo][ctx.attr.layer_type].to_list()
         },
     )
 

tests/container/BUILD

@@ -42,13 +42,13 @@ sh_test(
     size = "small",
     srcs = ["image_test.sh"],
     data = [
+        ":binary_image",
+        ":binary_image_explicit_layers",
         ":library_archive",
         ":library_image",
     ],
 )
 
-# TODO: Introduce tests for binary_image after moving to rules_docker.
-
 r_binary_image(
     name = "binary_image",
     base = "@r_base//image",

tests/container/image_test.sh

@@ -33,11 +33,13 @@ check() {
     echo "${TAR}" not found.
     exit 1
   fi
-  echo "Looking for file ${FILE_TO_CHECK} in ${TAR}:"
+  printf "Looking for file %s in %s: " "${FILE_TO_CHECK}" "${TAR}"
   if tar -tf "${TAR}" "${FILE_TO_CHECK}" >/dev/null 2>/dev/null; then
-    $EXPECT || (echo "Found but not expecting!" && exit 1)
+    ($EXPECT && echo "Found and expecting") || (echo "Found but not expecting!" && exit 1)
   elif $EXPECT; then
     echo "Not found!" && exit 1
+  else
+    echo "Not found and not expecting"
   fi
 }
 
@@ -49,4 +51,40 @@ check "library_image_internal-layer.tar" "./grail/r-libs/bitops/DESCRIPTION" "fa
 check "library_archive.tar.gz" "./grail/r-libs/exampleC/DESCRIPTION" "false"
 check "library_archive.tar.gz" "./grail/r-libs/bitops/DESCRIPTION" "true"
 
-echo "Found!"
+# TODO: Making an image by repo is not working as intended because all files
+# are also present in the topmost layer.
+
+# Check binary script and R library packages.
+check "binary_image-layer.tar" "/app/binary/binary" "true"
+check "binary_image-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/binary/binary.R" "true"
+check "binary_image-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/exampleA/lib/exampleA/DESCRIPTION" "true"
+check "binary_image-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/exampleB/lib/exampleB/DESCRIPTION" "true"
+check "binary_image-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/exampleC/lib/exampleC/DESCRIPTION" "true"
+check "binary_image-layer.tar" "./app/binary/binary.runfiles/R_bitops/lib/bitops/DESCRIPTION" "true"
+check "binary_image-layer.tar" "./app/binary/binary.runfiles/R_R6/lib/R6/DESCRIPTION" "true"
+
+# TODO: Making an image by explicit layers is currently broken because the
+# package files are not symlinked correctly because of change in behavior re
+# remap_main_repo.
+
+# Check that explicitly layered packages are not in the top layer, but in one layer below.
+check "binary_image_explicit_layers-layer.tar" "/app/binary/binary" "true"
+check "binary_image_explicit_layers-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/binary/binary.R" "true"
+check "binary_image_explicit_layers-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/exampleA/lib/exampleA/DESCRIPTION" "true"
+check "binary_image_explicit_layers-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/exampleB/lib/exampleB/DESCRIPTION" "true"
+check "binary_image_explicit_layers-layer.tar" "./app/binary/binary.runfiles/com_grail_rules_r_tests/exampleC/lib/exampleC/DESCRIPTION" "true"
+check "binary_image_explicit_layers-layer.tar" "./app/binary/binary.runfiles/R_bitops/lib/bitops/DESCRIPTION" "false"
+check "binary_image_explicit_layers-layer.tar" "./app/binary/binary.runfiles/R_R6/lib/R6/DESCRIPTION" "false"
+#check "binary_image_explicit_layers.0-layer.tar" "./app/binary/binary.runfiles/R_bitops/lib/bitops/DESCRIPTION" "true"
+check "binary_image_explicit_layers.0-layer.tar" "./app/binary/binary.runfiles/R_R6/lib/R6/DESCRIPTION" "false"
+check "binary_image_explicit_layers.1-layer.tar" "./app/binary/binary.runfiles/R_bitops/lib/bitops/DESCRIPTION" "false"
+#check "binary_image_explicit_layers.1-layer.tar" "./app/binary/binary.runfiles/R_R6/lib/R6/DESCRIPTION" "true"
+
+# TODO: fix image by explicit layers (see also TODO above).
+
+if docker --version; then
+  binary_image.executable
+  # binary_image_explicit_layers.executable
+fi
+
+echo "SUCCESS!"