Add minio tests to macOS test job

dev/tasks/homebrew-formulae/travis.osx.r.yml

@@ -45,9 +45,11 @@ before_install:
 - sed -i.bak -E -e 's@https://github.com/apache/arrow.git"$@{{ arrow.remote }}.git", :revision => "{{ arrow.head }}"@' tools/apache-arrow.rb && rm -f tools/apache-arrow.rb.bak
 # Sometimes crossbow gives a remote URL with .git and sometimes not. Make sure there's only one
 - sed -i.bak -E -e 's@.git.git@.git@' tools/apache-arrow.rb && rm -f tools/apache-arrow.rb.bak
+# Get minio for S3 testing
+- brew install minio/stable/minio
 script:
-- Rscript -e 'install.packages("rcmdcheck")'
+- Rscript -e 'install.packages(c("rcmdcheck", "sys"))'
 # Note that this is not --as-cran. CRAN doesn't do macOS checks --as-cran
-- travis_wait Rscript -e "rcmdcheck::rcmdcheck(build_args = '--no-build-vignettes', args = c('--no-manual', '--ignore-vignettes', '--run-donttest'), error_on = 'warning', check_dir = 'check')"
+- travis_wait Rscript -e "minio_dir <- tempfile(); dir.create(minio_dir); pid <- exec_background("minio", c("server", minio_dir)); on.exit(tools::pskill(pid)); rcmdcheck::rcmdcheck(build_args = '--no-build-vignettes', args = c('--no-manual', '--ignore-vignettes', '--run-donttest'), error_on = 'warning', check_dir = 'check')"
 # If there's a build failure, it's probably in this log. Let's print it regardless though
 - cat check/arrow.Rcheck/00install.out

r/README.md

@@ -179,6 +179,9 @@ features in the package build (S3 support, compression libraries, etc.).
 Others are generally skipped by default but can be enabled with environment
 variables or other settings:
 
+* All tests are skipped on Linux if the package builds without the C++ libarrow.
+  To make the build fail if libarrow is not available (as in, to test that
+  the C++ build was successful), set `TEST_R_WITH_ARROW=TRUE`
 * Some tests are disabled unless `ARROW_R_DEV=TRUE`
 * Tests that require allocating >2GB of memory to test Large types are disabled
   unless `ARROW_LARGE_MEMORY_TESTS=TRUE`